Inter-satellite baseline measurement method and device based on multi-reference joint calibration

Abstract

The invention discloses an inter-satellite baseline measurement method and device based on multi-reference joint calibration, and belongs to the technical field of space measurement. The method is realized by an inter-satellite baseline measurement device in the measurement system, and the measurement system further comprises a three-axis turntable, a laser vision fusion measurement device and a star sensor, the laser vision fusion measuring device rotates along with the rotation of the three-axis turntable; searching an auxiliary star target based on the three-axis turntable and the vision measurement module so as to enable the auxiliary star target to be located in a view field designated area of the vision measurement module; a laser ranging module and a vision measurement module are utilized to fuse and measure baseline data between the target and the auxiliary star target; the baseline data is obtained after mutual calibration of the laser ranging module and the vision measurement module; and performing attitude transmission by utilizing inertial attitudes of the star sensor and the vision measurement module on the same reference and combining the baseline data so as to obtain baseline data between the first position of the primary satellite and the second position of the auxiliary satellite. According to the invention, high-precision inter-satellite baseline measurement can be realized.

Description

Technical Field

[0001] The present invention relates to the field of space measurement technology, and in particular to an inter-satellite baseline measurement method and device based on multi-reference joint calibration. Background Art

[0002] When a distributed satellite formation works in collaboration, it is necessary to perform inter-satellite baseline measurement. In the related art, inter-satellite baseline measurement is achieved through GNSS navigation on the satellite. However, the inter-satellite baseline measurement obtained by GNSS navigation has poor accuracy, and a more accurate inter-satellite baseline measurement method is needed. Summary of the invention

[0003] The present invention provides an inter-satellite baseline measurement method and device based on multi-reference joint calibration, which can solve the problem of poor inter-satellite baseline measurement accuracy in related technologies. The technical solution is as follows:

[0004] On the one hand, a method for measuring intersatellite baselines based on multi-reference joint calibration is provided, which is implemented by an intersatellite baseline measurement device in a measurement system, wherein the measurement system is located in a main satellite of a distributed satellite formation, and the measurement system further comprises: a three-axis turntable, a laser vision fusion measurement device, and a star sensor; the laser vision fusion measurement device comprises: a laser ranging module and a visual measurement module; the laser vision fusion measurement device is fixedly connected to the three-axis turntable, and the laser vision fusion measurement device rotates with the rotation of the three-axis turntable; the method comprises:

[0005] Searching for the auxiliary satellite target based on the three-axis turntable and the visual measurement module so that the auxiliary satellite target is located in the specified area of ​​the field of view of the visual measurement module;

[0006] The laser ranging module and the visual measurement module are used to fuse and measure the baseline data between the laser vision fusion measurement device and the auxiliary satellite target; the baseline data is obtained after the laser ranging module and the visual measurement module are calibrated with each other;

[0007] The inertial attitude of the star sensor and the visual measurement module on the same reference is used to perform attitude transfer in combination with the baseline data to obtain the baseline data between the first position of the primary satellite and the second position of the auxiliary satellite.

[0008] On the other hand, an intersatellite baseline measurement device based on multi-reference joint calibration is provided, which is located in a measurement system, wherein the measurement system is located in a main satellite of a distributed satellite formation, and the measurement system further comprises: a three-axis turntable, a laser vision fusion measurement device and a star sensor; the laser vision fusion measurement device comprises: a laser ranging module and a visual measurement module; the laser vision fusion measurement device is fixedly connected to the three-axis turntable, and the laser vision fusion measurement device rotates with the rotation of the three-axis turntable; the intersatellite baseline measurement device comprises:

[0009] A target search unit, used for searching the auxiliary satellite target based on the three-axis turntable and the visual measurement module, so that the auxiliary satellite target is located in a designated area of ​​the field of view of the visual measurement module;

[0010] A fusion measurement unit, used to obtain the baseline data between the laser vision fusion measurement device and the auxiliary satellite target obtained by the fusion measurement of the laser ranging module and the vision measurement module; the baseline data is obtained after the laser ranging module and the vision measurement module are calibrated with each other;

[0011] The attitude transfer calculation unit is used to obtain the inertial attitude of the star sensor and the visual measurement module on the same reference, and perform attitude transfer in combination with the baseline data to obtain the baseline data between the first position of the primary satellite and the second position of the auxiliary satellite.

[0012] On the other hand, a measurement system is provided, the measurement system is located in the main satellite of the distributed satellite formation, the measurement system further comprises: a three-axis turntable, a laser vision fusion measurement device and a star sensor; the laser vision fusion measurement device comprises: a laser ranging module and a visual measurement module; the laser vision fusion measurement device is fixedly connected to the three-axis turntable, and the laser vision fusion measurement device rotates following the rotation of the three-axis turntable;

[0013] The inter-satellite baseline measurement device is used to search for the auxiliary satellite target based on the three-axis turntable and the visual measurement module, so that the auxiliary satellite target is located in the specified area of ​​the field of view of the visual measurement module; obtain the baseline data between the laser vision fusion measurement device and the auxiliary satellite target obtained by the fusion measurement of the laser ranging module and the visual measurement module; the baseline data is obtained after the laser ranging module and the visual measurement module are calibrated with each other; obtain the inertial attitude of the star sensor and the visual measurement module on the same reference, combine the baseline data for attitude transfer, and obtain the baseline data between the first position of the primary satellite and the second position of the auxiliary satellite.

[0014] On the other hand, a computer device is provided, comprising a memory and a processor, wherein the memory is used to store a computer program, and the processor is used to execute the computer program stored in the memory to implement the steps of the above-mentioned inter-satellite baseline measurement method based on multi-reference joint calibration.

[0015] On the other hand, a computer-readable storage medium is provided, wherein a computer program is stored in the storage medium, and when the computer program is executed by a processor, the steps of the above-mentioned inter-satellite baseline measurement method based on multi-reference joint calibration are implemented.

[0016] On the other hand, a computer program product is provided, including a computer program, which, when executed by a processor, implements the steps of the above-mentioned inter-satellite baseline measurement method based on multi-reference joint calibration.

[0017] The technical solution provided by the present invention can at least bring the following beneficial effects:

[0018] The auxiliary satellite target is searched by using a three-axis turntable and a visual measurement module, so that the auxiliary satellite target is located in the specified area of ​​the field of view of the visual measurement module, thereby improving the measurement accuracy of the visual measurement module and the laser ranging module, and the visual measurement module and the laser ranging module perform fusion measurement on the baseline data, and the baseline data is obtained after the laser ranging module and the visual measurement module are calibrated mutually, which further improves the measurement accuracy. Furthermore, the inertial attitude of the star sensor and the visual measurement module on the same reference is measured, and the attitude transfer is performed in combination with the baseline data of the fusion measurement to obtain the baseline data between the first position of the main satellite and the second position of the auxiliary satellite, thereby eliminating the intermediate error, suppressing the error accumulation, and realizing the high-precision inter-satellite baseline measurement. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0020] Figure 1 This is a flow chart of an inter-satellite baseline measurement method based on multi-reference joint calibration provided by an embodiment of the present invention;

[0021] Figure 2 It is a structural diagram of an inter-satellite baseline measurement device based on multi-reference joint calibration provided by one embodiment of the present invention;

[0022] Figure 3 It is a hardware architecture diagram of a computer device provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0023] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0024] Please refer to Figure 1 An intersatellite baseline measurement method based on multi-reference joint calibration provided by an embodiment of the present invention is implemented by an intersatellite baseline measurement device in a measurement system, the measurement system is located in the main satellite of a distributed satellite formation, the measurement system further comprises: a three-axis turntable, a laser vision fusion measurement device and a star sensor; the laser vision fusion measurement device comprises: a laser ranging module and a visual measurement module; the laser vision fusion measurement device is fixedly connected to the three-axis turntable, and the laser vision fusion measurement device rotates with the rotation of the three-axis turntable; the method comprises:

[0025] Step 100, searching for the auxiliary satellite target based on the three-axis turntable and the visual measurement module, so that the auxiliary satellite target is located in the designated area of ​​the field of view of the visual measurement module;

[0026] Step 102, using the laser ranging module and the visual measurement module to fuse and measure the baseline data between the laser vision fusion measurement device and the auxiliary satellite target; the baseline data is obtained after the laser ranging module and the visual measurement module are calibrated with each other;

[0027] Step 104 , using the inertial attitude of the star sensor and the visual measurement module on the same reference, combined with the baseline data, attitude transfer is performed to obtain the baseline data between the first position of the primary satellite and the second position of the auxiliary satellite.

[0028] In the embodiment of the present invention, a three-axis turntable and a visual measurement module are used to search for an auxiliary satellite target, so that the auxiliary satellite target is located in a designated area of ​​the visual measurement module's field of view, thereby improving the measurement accuracy of the visual measurement module and the laser ranging module, and the visual measurement module and the laser ranging module perform fusion measurement on baseline data, and the baseline data is obtained after the laser ranging module and the visual measurement module are calibrated with each other, further improving the measurement accuracy, and further, the inertial attitude of the star sensor and the visual measurement module on the same reference is measured, and the attitude transfer is performed in combination with the baseline data of the fusion measurement, so as to obtain the baseline data between the first position of the primary satellite and the second position of the auxiliary satellite, thereby eliminating intermediate errors, suppressing error accumulation, and realizing high-precision inter-satellite baseline measurement.

[0029] In the embodiment of the present invention, a three-axis turntable, a laser vision fusion measurement device and a star sensor are introduced on the satellite platform of the main satellite. By rotating the three-axis turntable, the laser vision fusion measurement device can be aligned with the auxiliary satellite target, thereby achieving accurate measurement. In addition, the laser vision fusion measurement device includes a visual measurement module and a laser ranging module. The visual measurement module is used to measure the baseline data in two dimensions, and the laser ranging module is used to measure the baseline data in one dimension. The two are fused to obtain three-dimensional baseline data; and the star sensor and the visual measurement module are used to realize attitude transfer with a common reference, which can suppress error accumulation. It can be seen that this scheme can achieve high-precision inter-satellite baseline measurement through multi-reference joint calibration.

[0030] Described below Figure 1 How the various steps are performed.

[0031] First, for step 100 , the auxiliary satellite target is searched based on the three-axis turntable and the vision measurement module, so that the auxiliary satellite target is located within the specified area of ​​the field of view of the vision measurement module.

[0032] In an embodiment of the present invention, a distributed satellite formation includes multiple satellites, including a primary satellite and an auxiliary satellite. The primary satellite needs to measure the baseline data between the primary satellite and the auxiliary satellite. During the measurement, a target is set on the auxiliary satellite for the primary satellite to achieve the measurement of the baseline data through the target.

[0033] In the embodiment of the present invention, the visual measurement module calculates the posture of the auxiliary satellite target relative to the visual measurement module by photographing the auxiliary satellite target, so it is necessary to ensure that the auxiliary satellite target is located within the field of view of the visual measurement module.

[0034] This step may specifically include steps A1-A3:

[0035] A1: Acquire the current field of view image based on the visual measurement module, and determine whether there is an auxiliary satellite target in the current field of view image; if there is, execute step A2; if not, execute step A3;

[0036] A2: Determine whether the auxiliary satellite target is located in the specified area of ​​the current field of view image; if not, based on the position of the auxiliary satellite target in the current field of view image, control the three-axis turntable to make the auxiliary satellite target located in the specified area;

[0037] The designated area is the central area of ​​the current field of view image.

[0038] In the embodiment of the present invention, when the auxiliary satellite target is located in the current field of view image of the visual measurement module, the visual measurement module can calculate the posture of the auxiliary satellite target relative to the visual measurement module based on the auxiliary satellite target. However, if the auxiliary satellite target is located in the specified area of ​​the current field of view image of the visual measurement module, it can effectively eliminate error factors such as imaging distortion and improve the accuracy of the measurement result.

[0039] If the auxiliary satellite target is not located in the specified area of ​​the current field of view image, the three-axis turntable can be controlled to rotate according to the position of the auxiliary satellite target in the current field of view image so that the auxiliary satellite target is located in the specified area. The control amount of the three-axis turntable can be calculated by the current posture of the three-axis turntable, the installation matrix of the laser vision fusion measurement device on the three-axis turntable, and the current posture of the auxiliary satellite target, so as to realize the adjustment of the three-axis rotation to the target direction.

[0040] A3: Control the three-axis turntable to rotate according to the set program, and execute step A1 after the rotation is completed.

[0041] Among them, the setting procedure can be that the field of view area of ​​each rotation of the three-axis turntable is smaller than the field of view area of ​​the visual measurement module. For example, the field of view area of ​​the visual measurement module is A1×B1, and the field of view area of ​​each rotation of the three-axis turntable is A2×B2, A2<A1, B2<B1. In this way, it can be determined that after each rotation of the three-axis turntable, the capture of the auxiliary satellite target will not be missed due to the excessive rotation field of view area. In addition, the setting procedure requires that the three-axis turntable rotates multiple times to enable the field of view area of ​​the visual measurement module to cover the entire space area, so that the auxiliary satellite target can be captured as soon as possible.

[0042] The embodiment of the present invention realizes the initial capture of the auxiliary satellite target through the three-axis turntable and the vision measurement module, and provides initial pointing information for the precise measurement of the laser vision fusion measurement device. The laser vision fusion measurement device is fixedly connected to the three-axis turntable and can rotate with the rotation of the three-axis turntable. Compared with the fixed posture measurement, the measurement range is expanded, thereby improving the measurement accuracy.

[0043] Then, for step 102, the laser ranging module and the visual measurement module are used to fuse and measure the baseline data between the laser vision fusion measurement device and the auxiliary satellite target; the baseline data is obtained after the laser ranging module and the visual measurement module are calibrated with each other.

[0044] In the embodiment of the present invention, the laser distance measurement module and the visual measurement module measure the target respectively. The following describes the measurement methods of the two respectively.

[0045] First, the laser ranging module is described.

[0046] In order to improve the measurement accuracy of the laser ranging module, in one embodiment of the present invention, the laser ranging module includes: a photoelectric balance detector and a laser unit; the laser unit is used to emit frequency modulated continuous wave laser and femtosecond laser.

[0047] Then, the measurement method of the laser ranging module may include: using a photoelectric balanced detector to process the interference mixing signal of the frequency modulated continuous wave laser and the femtosecond laser to obtain the two-phase orthogonal quantity of the beat frequency of the two lasers; and using the two-phase orthogonal quantity of the beat frequency of the two lasers to resolve the frequency of the calibrated frequency modulated continuous wave laser; and using the frequency of the calibrated frequency modulated continuous wave laser to calculate the baseline data between the auxiliary satellite target.

[0048] In the related technology, the frequency of the frequency modulated continuous wave laser FMCW is given directly, but the frequency modulated continuous wave laser has nonlinear distortion, which leads to poor accuracy of the calculation results directly using the given frequency. Therefore, a femtosecond laser is introduced to calibrate the frequency of the frequency modulated continuous wave laser with high precision through frequency mixing, so that the calibrated frequency can be used to calculate the high-precision baseline data between the auxiliary satellite target.

[0049] The visual measurement module is then described.

[0050] In an embodiment of the present invention, the measurement method of the visual measurement module may include: using the visual measurement module to extract the coordinate position of the auxiliary satellite target in the image coordinate system for the current visual image, and using the coordinate position to calculate the posture of the auxiliary satellite target.

[0051] Among them, m array target points are set on the auxiliary satellite target, and the visual measurement module images the m array target points. By constructing 2m nonlinear equations, the posture of the auxiliary satellite target relative to the laser vision fusion measurement device can be calculated.

[0052] Since there are interference errors in both monocular vision and laser ranging, the embodiment of the present invention combines visual measurement and laser ranging to complete ranging and attitude measurement. Among them, monocular vision can measure the distance through the relationship between pixel coordinates and the actual size of the auxiliary satellite target, while laser ranging can measure the distance by emitting laser pulses. The measurement results of the two are used to transform the coordinate system, so as to realize the fusion of measurement data under the two measurement systems of laser and vision, and obtain the position and attitude of the auxiliary satellite target in the visual coordinate system. It can be seen that through fusion measurement, the shortcomings of single measurement method can be compensated and the accuracy and reliability of measurement results can be improved.

[0053] It should be noted that the translation vector and rotation matrix between the laser ranging module and the visual measurement module are pre-calibrated with high precision, so the accurate fusion of the measurement data of the two can be achieved through coordinate system transformation.

[0054] Furthermore, in order to achieve the measurement benchmark of the visual measurement module and the laser ranging module, in one embodiment of the present invention, the auxiliary star target includes at least three corner cube prisms, and the at least three corner cube prisms form a three-dimensional configuration; the laser ranging module and the visual measurement module share the auxiliary star target; in addition, the visual measurement module is also configured with an illumination light source, and the target has high reflectivity in the illumination band of the visual measurement module and the working band of the laser ranging module, and can be used for visual imaging and laser ranging at the same time, so that the visual measurement module and the laser ranging module have the same measurement benchmark for the auxiliary star target, thereby improving the measurement accuracy.

[0055] Assume that the auxiliary satellite target coordinate system is the target coordinate system O T -X T Y T Z T , the body coordinate system of the visual measurement module is the visual measurement coordinate system O C -X C Y C Z C , the main coordinate system of the laser ranging module is the laser measurement coordinate system O L -X L Y L Z L , the rotation matrix from the target coordinate system to the visual measurement coordinate system is The translation vector from the visual measurement coordinate system to the target coordinate system is: The rotation matrix from the visual measurement coordinate system to the laser measurement coordinate system is: The translation vector from the laser measurement coordinate system to the visual measurement coordinate system is: in, and Can be obtained through external calibration means, and To be measured.

[0056] The auxiliary star target is the feature point of the auxiliary star target. The coordinates of the i-th target in the target coordinate system are [X i T ,Y i T ,Z i T ] H (i=1,2,…,N, N is the number of targets), the coordinates in the visual measurement coordinate system are denoted as [X i C ,Y i C ,Z i C ] H, where the symbol H represents the transpose of a matrix or vector. The Euler angles from the target coordinate system to the visual measurement coordinate system are denoted as γ, α, and β. The three angles determine the rotation matrix The value of; translation vector Then it is recorded as [x,y,z] H , γ, α, β, x, y, z are the six unknown quantities to be solved, and Y i C and Z i C are all functions of these six unknown quantities.

[0057] Then the fusion measurement method of step 102 includes:

[0058] Step 1020: acquiring a target image obtained by imaging the auxiliary satellite target using a visual measurement module, extracting the two-dimensional coordinates of the target in the image plane coordinate system from the target image, and determining the orientation of the target in the visual measurement coordinate system according to the two-dimensional coordinates of the target;

[0059] Step 1022: according to the orientation of the ranging target in the visual measurement coordinate system, the coordinate transformation relationship between the visual measurement coordinate system and the laser measurement coordinate system is used to obtain the orientation of the ranging target in the laser measurement coordinate system; according to the orientation of the ranging target in the laser measurement coordinate system, the light beam transmission direction of the laser ranging module is adjusted so that the light beam points to the ranging target, and then the distance of the ranging target is measured by the laser ranging module; the ranging target is part of the target or all the targets in the cooperative target array;

[0060] Step 1024: using the coordinate transformation relationship between the visual measurement coordinate system and the laser measurement coordinate system, convert the distance of the ranging target to the three-dimensional position of the ranging target in the visual measurement coordinate system;

[0061] Step 1026: For the ranging target, a ranging equation is established according to the three-dimensional position of the ranging target and the coordinate transformation relationship between the visual measurement coordinate system and the target coordinate system; for the non-ranging target, a non-ranging equation is established according to the two-dimensional coordinates of the non-ranging target in the image plane coordinate system and the pinhole imaging model; the equation group formed by all targets is solved to obtain the actual baseline data between the visual measurement module and the auxiliary satellite target.

[0062] It can be understood that the imaging of the auxiliary satellite target by the visual measurement module is completed when the illumination light source illuminates the auxiliary satellite target.

[0063] The distance to the target is measured by the laser ranging module. Finally, the measurement results of the laser ranging module and the visual measurement module need to be integrated. Therefore, the coordinate transformation relationship between the visual measurement coordinate system and the laser measurement coordinate system can be used to convert the distance of the ranging target into the three-dimensional position of the ranging target in the visual measurement coordinate system.

[0064] Assuming that the number of ranging targets is m and the serial number of the ranging targets is N-m+1-N, then according to the three-dimensional position of the ranging targets, the equations corresponding to these ranging targets in the above equations can be directly replaced to obtain a nonlinear equation group consisting of 2N+m equations; that is:

[0065] The non-range measurement equation established for the non-range measurement target (the serial number of the non-range measurement target is 1-Nm) is:

[0066]

[0067] The distance measurement equation established for the distance measurement target (the sequence number of the distance measurement target is N-m+1-N) is:

[0068]

[0069] Among them, γ, α, β are the Euler angles from the target coordinate system to the visual measurement coordinate system; [x, y, z] H is the translation vector from the visual measurement coordinate system to the target coordinate system; is the two-dimensional coordinate of the target in the image plane coordinate system; is the coordinate of the i-th target in the visual measurement coordinate system; is to convert the distance of the i-th target to the three-dimensional position in the visual measurement coordinate system; F is the focal length of the visual measurement module; N is the total number of targets in the cooperative target array, N is an integer not less than 3; m is the number of ranging targets, m is an integer not less than 1 and not greater than N, the 1st to (Nm)th targets are non-ranging targets, and the (N-m+1)th to Nth targets are ranging targets;

[0070] in, is the coordinate of the i-th target in the target coordinate system, It is the rotation matrix from the target coordinate system to the visual measurement coordinate system, which is determined by the Euler angle.

[0071] In the nonlinear equation group composed of the above 2N+m equations, the target information measured by the laser ranging module can impose effective constraints on the distance to the target position for target measurement, make up for the shortcomings of the traditional visual measurement module, and improve the measurement accuracy of the relative position of the target in the z-axis direction in the iterative calculation results.

[0072] Finally, for step 104, the inertial attitudes of the star sensor and the visual measurement module on the same reference are used in combination with the baseline data to perform attitude transfer to obtain the baseline data between the first position of the primary satellite and the second position of the auxiliary satellite.

[0073] The inter-satellite baseline data required in practical applications is not the baseline data between the target and the laser vision fusion measurement device, but the baseline data between the first position of the primary satellite and the second position of the auxiliary satellite. For example, the first position and the second position are both antennas, which means that the baseline data between the primary satellite antenna and the auxiliary satellite antenna needs to be measured.

[0074] If the baseline data measured by the laser vision fusion measurement device is directly used to transfer the attitude between the first position of the primary satellite and the first position of the auxiliary satellite, there will be pointing errors of the servo mechanism when driving the three-axis turntable, installation errors of the laser vision fusion measurement device, thermal drift, etc. that affect the measurement accuracy. Therefore, in the embodiment of the present invention, a star sensor is introduced to complete the common reference attitude transfer of the star sensor and the visual measurement module to eliminate intermediate errors and suppress error accumulation.

[0075] Specifically, this step 104 may include:

[0076] B1: Use the visual measurement module to determine the first inertial posture of the vehicle relative to the inertial space;

[0077] B2: Use the star sensor to determine its second inertial attitude relative to the inertial space, and use the installation matrix of the star sensor on the primary star and the second inertial attitude of the star sensor to calculate the third inertial attitude of the primary star relative to the inertial space;

[0078] B3: Based on the first inertial attitude of the visual measurement module and the third inertial attitude of the main star, the attitude of the visual measurement module relative to the main star is calculated;

[0079] B4: using the baseline data between the laser vision fusion measurement device and the auxiliary satellite target, combined with the posture of the visual measurement module relative to the main star body, the posture of the auxiliary satellite target relative to the main star body is calculated;

[0080] B5: The baseline data of the first position of the main satellite and the second position of the auxiliary satellite are calculated by using the direction of the main satellite body relative to the first position of the main satellite and the direction of the auxiliary satellite target relative to the second position of the auxiliary satellite.

[0081] In the embodiment of the present invention, the orientation of the primary star body relative to the primary star first position may be determined based on the installation matrix of the primary star first position on the primary star.

[0082] The direction of the auxiliary satellite target relative to the auxiliary satellite's second position can be obtained in the following two ways:

[0083] Method 1: Acquisition of prior information based on high-precision ground calibration;

[0084] Method 2: Obtain based on on-orbit calibration.

[0085] In the first method, the prior information of high-precision ground calibration can be directly used to obtain the direction of the auxiliary satellite target relative to the second position of the auxiliary satellite.

[0086] In the second method, a visual measurement module is set on the auxiliary satellite target, a star sensor is set on the auxiliary satellite, and then the direction of the auxiliary satellite target relative to the second position of the auxiliary satellite is obtained by the following calibration method:

[0087] C1: The fourth inertial attitude of the auxiliary satellite target relative to the inertial space is determined by the visual measurement module on the auxiliary satellite target;

[0088] C2: The star sensor on the auxiliary satellite determines its fifth inertial attitude relative to the inertial space, and uses the installation matrix of the star sensor on the auxiliary satellite and the fifth inertial attitude to calculate the sixth inertial attitude of the auxiliary star body relative to the inertial space;

[0089] C3: Calculate the attitude of the auxiliary satellite target relative to the auxiliary satellite body using the fourth inertial attitude and the sixth inertial attitude;

[0090] C4: Determine the direction of the auxiliary star body relative to the second position of the auxiliary satellite using the installation matrix of the second position of the auxiliary satellite on the auxiliary satellite;

[0091] C5: Determine the direction of the auxiliary satellite target relative to the auxiliary satellite second position by using the posture of the auxiliary satellite target relative to the auxiliary satellite body and the direction of the auxiliary satellite body relative to the auxiliary satellite second position.

[0092] After obtaining the orientation of the primary star body relative to the primary star's first position and the orientation of the secondary star target relative to the secondary star's second position, the baseline data of the primary star's first position and the secondary star's second position can be calculated.

[0093] In the embodiment of the present invention, the inertial attitude is used as the absolute reference and the intermediate transfer amount, which can suppress the accumulation of errors and realize the high-precision inter-satellite baseline measurement under the condition of multiple measurement references.

[0094] In one embodiment of the present invention, after calculating the baseline data between the first position of the primary satellite and the second position of the auxiliary satellite, it may also include: according to the baseline data between the first position of the primary satellite and the second position of the auxiliary satellite, controlling the three-axis turntable to follow the baseline direction to obtain the baseline measurement result in real time.

[0095] By controlling the three-axis turntable to follow the direction of the baseline, continuous tracking of the baseline and rapid output of measurement results can be achieved, thereby improving the availability of on-orbit baseline measurement results.

[0096] Similarly, the control quantity that controls the three-axis turntable to follow the baseline direction can be solved by the installation matrix of the three-axis turntable, the current angle of the three-axis turntable and the baseline direction to calculate the command angle of the three-axis turntable, thereby controlling the three-axis turntable to adjust the three-axis angle according to the command angle.

[0097] Based on the same inventive concept as the above-mentioned inter-satellite baseline measurement method based on multi-reference joint calibration, an embodiment of the present invention provides an inter-satellite baseline measurement device based on multi-reference joint calibration, which is located in a measurement system, and the measurement system is located in the main satellite of a distributed satellite formation. The measurement system also includes: a three-axis turntable, a laser vision fusion measurement device and a star sensor; the laser vision fusion measurement device includes: a laser ranging module and a visual measurement module; the laser vision fusion measurement device is fixedly connected to the three-axis turntable, and the laser vision fusion measurement device rotates with the rotation of the three-axis turntable; the system also includes an inter-satellite baseline measurement device based on multi-reference joint calibration; please refer to Figure 2 , the inter-satellite baseline measurement device comprises:

[0098] A target search unit 200 is used to search for auxiliary satellite targets based on a three-axis turntable and a visual measurement module so that the auxiliary satellite targets are located within a designated area of ​​the visual field of the visual measurement module;

[0099] A fusion measurement unit 202 is used to obtain baseline data between the laser vision fusion measurement device and the auxiliary satellite target obtained by fusion measurement of the laser ranging module and the vision measurement module; the baseline data is obtained after mutual calibration of the laser ranging module and the vision measurement module;

[0100] The attitude transfer calculation unit 204 is used to obtain the inertial attitude of the star sensor and the visual measurement module on the same reference, and perform attitude transfer in combination with the baseline data to obtain the baseline data between the first position of the primary satellite and the second position of the auxiliary satellite.

[0101] In one embodiment of the present invention, the target search unit is specifically configured to perform the following operations:

[0102] A1: Acquire the current field of view image based on the visual measurement module, and determine whether there is an auxiliary satellite target in the current field of view image; if there is, execute step A2; if not, execute step A3;

[0103] A2: Determine whether the auxiliary satellite target is located in the specified area of ​​the current field of view image; if not, based on the position of the auxiliary satellite target in the current field of view image, control the three-axis turntable to make the auxiliary satellite target located in the specified area;

[0104] A3: Control the three-axis turntable to rotate according to the set program, and execute step A1 after the rotation is completed.

[0105] In one embodiment of the present invention, the laser ranging module comprises: a photoelectric balance detector and a laser unit; the laser unit is used to emit frequency modulated continuous wave laser and femtosecond laser;

[0106] The measurement method of the laser ranging module includes:

[0107] The interference mixing signals of the frequency modulated continuous wave laser and the femtosecond laser are processed by using a photoelectric balanced detector to obtain the two-phase orthogonal quantity of the beat frequency of the two lasers; and the two-phase orthogonal quantity of the beat frequency of the two lasers is used to resolve the frequency of the calibrated frequency modulated continuous wave laser; and the baseline data between the auxiliary satellite target is calculated by using the frequency of the calibrated frequency modulated continuous wave laser.

[0108] In one embodiment of the present invention, the posture transfer calculation unit is specifically used to perform the following operations:

[0109] Determine the first inertial posture of the body relative to the inertial space by using the visual measurement module;

[0110] Using the star sensor to determine its own second inertial attitude relative to the inertial space, and using the installation matrix of the star sensor on the primary star and the second inertial attitude of the star sensor to calculate the third inertial attitude of the primary star relative to the inertial space;

[0111] Based on the first inertial attitude of the visual measurement module and the third inertial attitude of the main star body, the attitude of the visual measurement module relative to the main star body is calculated;

[0112] The attitude of the auxiliary satellite target relative to the main star object is calculated by using the baseline data between the laser vision fusion measurement device and the auxiliary satellite target and combining the attitude of the visual measurement module relative to the main star object;

[0113] The baseline data of the first position of the main satellite and the second position of the auxiliary satellite are calculated by using the direction of the main satellite body relative to the first position of the main satellite and the direction of the auxiliary satellite target relative to the second position of the auxiliary satellite.

[0114] In one embodiment of the present invention, a visual measurement module is provided on the auxiliary satellite target, and a star sensor is provided on the auxiliary satellite;

[0115] The direction of the auxiliary satellite target relative to the second position of the auxiliary satellite is determined as follows:

[0116] Determining a fourth inertial attitude of the auxiliary satellite target relative to the inertial space by a visual measurement module on the auxiliary satellite target;

[0117] The star sensor on the auxiliary satellite determines its fifth inertial attitude relative to the inertial space, and the installation matrix of the star sensor on the auxiliary satellite and the fifth inertial attitude are used to calculate the sixth inertial attitude of the auxiliary star body relative to the inertial space;

[0118] Calculating the attitude of the auxiliary satellite target relative to the auxiliary satellite body by using the fourth inertial attitude and the sixth inertial attitude;

[0119] Determine the direction of the auxiliary star body relative to the second position of the auxiliary satellite using the installation matrix of the second position of the auxiliary satellite on the auxiliary satellite;

[0120] The orientation of the auxiliary satellite target relative to the auxiliary satellite second position is determined by using the posture of the auxiliary satellite target relative to the auxiliary satellite body and the orientation of the auxiliary satellite body relative to the auxiliary satellite second position.

[0121] In one embodiment of the present invention, the inter-satellite baseline measurement device based on multi-reference joint calibration may further include:

[0122] The control unit is used to control the three-axis turntable to follow the baseline direction according to the baseline data between the first position of the primary satellite and the second position of the auxiliary satellite, so as to obtain the baseline measurement result in real time.

[0123] It should be noted that the inter-satellite baseline measurement device based on multi-reference joint calibration provided in the above embodiment is only illustrated by the division of the above functional modules. In practical applications, the above functions can be assigned to different functional modules as needed, that is, the internal structure of the device is divided into different functional modules to complete all or part of the functions described above. In addition, the inter-satellite baseline measurement device based on multi-reference joint calibration provided in the above embodiment and the inter-satellite baseline measurement method embodiment based on multi-reference joint calibration belong to the same concept. The specific implementation process is detailed in the method embodiment and will not be repeated here.

[0124] Based on the same inventive concept as the above-mentioned inter-satellite baseline measurement method based on multi-reference joint calibration, an embodiment of the present invention provides a measurement system, the measurement system is located in the main satellite of the distributed satellite formation, the measurement system also includes: a three-axis turntable, a laser vision fusion measurement device and a star sensor; the laser vision fusion measurement device includes: a laser ranging module and a visual measurement module; the laser vision fusion measurement device is fixedly connected to the three-axis turntable, and the laser vision fusion measurement device rotates following the rotation of the three-axis turntable;

[0125] The inter-satellite baseline measurement device is used to search for the auxiliary satellite target based on the three-axis turntable and the visual measurement module, so that the auxiliary satellite target is located in the specified area of ​​the field of view of the visual measurement module; obtain the baseline data between the laser vision fusion measurement device and the auxiliary satellite target obtained by the fusion measurement of the laser ranging module and the visual measurement module; the baseline data is obtained after the laser ranging module and the visual measurement module are calibrated with each other; obtain the inertial attitude of the star sensor and the visual measurement module on the same reference, combine the baseline data for attitude transfer, and obtain the baseline data between the first position of the primary satellite and the second position of the auxiliary satellite.

[0126] The embodiment of the present application also provides a computer device, please refer to Figure 3 The computer device includes a processor and a memory, wherein at least one instruction, at least one program, a code set or an instruction set is stored in the memory, and the at least one instruction, at least one program, a code set or an instruction set is loaded and executed by the processor to implement the inter-satellite baseline measurement method based on multi-reference joint calibration provided by the above-mentioned method embodiments.

[0127] An embodiment of the present application also provides a computer-readable storage medium, on which is stored at least one instruction, at least one program, code set or instruction set, and the at least one instruction, at least one program, code set or instruction set is loaded and executed by a processor to implement the inter-satellite baseline measurement method based on multi-reference joint calibration provided by the above-mentioned method embodiments.

[0128] An embodiment of the present application also provides a computer program product, which includes a computer program. A processor of a computer device reads the computer program from a computer-readable storage medium, and the processor executes the computer program, so that the computer device executes the inter-satellite baseline measurement method based on multi-reference joint calibration described in any of the above embodiments.

[0129] For the convenience of description, the above system or device is described by dividing it into various modules or units according to its functions. Of course, when implementing the present application, the functions of each unit can be implemented in the same or multiple software and / or hardware.

[0130] It can be known from the description of the above implementation methods that those skilled in the art can clearly understand that the present application can be implemented by means of software plus a necessary general hardware platform. Based on such an understanding, the technical solution of the present application can be essentially or partly contributed to the prior art in the form of a software product, which can be stored in a storage medium such as ROM / RAM, a magnetic disk, an optical disk, etc., and includes several instructions for enabling a computer device (which can be a personal computer, a server, or a network device, etc.) to execute the methods described in the various embodiments of the present application or certain parts of the embodiments.

[0131] Finally, it should be noted that, in this article, relational terms such as first, second, third and fourth are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the statement "comprise a ..." do not exclude the presence of other identical elements in the process, method, article or device including the elements.

[0132] The above is only a preferred implementation of the present application. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present application. These improvements and modifications should also be regarded as the scope of protection of the present application.

Claims

1. An inter-satellite baseline measurement method based on multi-reference joint calibration, characterized in that: The method is implemented by an intersatellite baseline measurement device in a measurement system, the measurement system is located in the main satellite of a distributed satellite formation, the measurement system further comprises: a three-axis turntable, a laser vision fusion measurement device and a star sensor; the laser vision fusion measurement device comprises: a laser ranging module and a visual measurement module; the laser vision fusion measurement device is fixedly connected to the three-axis turntable, and the laser vision fusion measurement device rotates with the rotation of the three-axis turntable; the method comprises: Searching for the auxiliary satellite target based on the three-axis turntable and the visual measurement module so that the auxiliary satellite target is located in the specified area of ​​the field of view of the visual measurement module; The laser ranging module and the visual measurement module are used to fuse and measure the baseline data between the laser vision fusion measurement device and the auxiliary satellite target; the baseline data is obtained after the laser ranging module and the visual measurement module are calibrated with each other; The inertial attitude of the star sensor and the visual measurement module on the same reference is used to perform attitude transfer in combination with the baseline data to obtain the baseline data between the first position of the primary satellite and the second position of the auxiliary satellite.

2. The method according to claim 1, characterized in that The method of searching for the auxiliary satellite target based on the three-axis turntable and the laser vision measuring device so that the auxiliary satellite target is located within the field of view target area of ​​the laser vision measuring device includes: A1: Acquire the current field of view image based on the visual measurement module, and determine whether there is an auxiliary satellite target in the current field of view image; if there is, execute step A2; if not, execute step A3; A2: Determine whether the auxiliary satellite target is located in the specified area of ​​the current field of view image; if not, based on the position of the auxiliary satellite target in the current field of view image, control the three-axis turntable to make the auxiliary satellite target located in the specified area; A3: Control the three-axis turntable to rotate according to the set program, and execute step A1 after the rotation is completed.

3. The method according to claim 1, characterized in that: The laser ranging module comprises: a photoelectric balance detector and a laser unit; the laser unit is used to emit frequency modulated continuous wave laser and femtosecond laser; The measurement method of the laser ranging module includes: The interference mixing signals of the frequency modulated continuous wave laser and the femtosecond laser are processed by using a photoelectric balanced detector to obtain the two-phase orthogonal quantity of the beat frequency of the two lasers; and the two-phase orthogonal quantity of the beat frequency of the two lasers is used to resolve the frequency of the calibrated frequency modulated continuous wave laser; and the baseline data between the auxiliary satellite target is calculated by using the frequency of the calibrated frequency modulated continuous wave laser.

4. The method according to claim 1, characterized in that: The inertial attitude of the star sensor and the visual measurement module on the same reference is used to transfer the attitude in combination with the baseline data to obtain the baseline data between the first position of the primary satellite and the second position of the auxiliary satellite, including: Determine the first inertial posture of the body relative to the inertial space by using the visual measurement module; Using the star sensor to determine its own second inertial attitude relative to the inertial space, and using the installation matrix of the star sensor on the primary star and the second inertial attitude of the star sensor to calculate the third inertial attitude of the primary star relative to the inertial space; Based on the first inertial attitude of the visual measurement module and the third inertial attitude of the main star body, the attitude of the visual measurement module relative to the main star body is calculated; The attitude of the auxiliary satellite target relative to the main star object is calculated by using the baseline data between the laser vision fusion measurement device and the auxiliary satellite target and combining the attitude of the visual measurement module relative to the main star object; The baseline data of the first position of the main satellite and the second position of the auxiliary satellite are calculated by using the direction of the main satellite body relative to the first position of the main satellite and the direction of the auxiliary satellite target relative to the second position of the auxiliary satellite.

5. The method according to claim 4, characterized in that A visual measurement module is arranged on the auxiliary satellite target, and a star sensor is arranged on the auxiliary satellite; The direction of the auxiliary satellite target relative to the second position of the auxiliary satellite is determined as follows: Determining a fourth inertial attitude of the auxiliary satellite target relative to the inertial space by a visual measurement module on the auxiliary satellite target; The star sensor on the auxiliary satellite determines its fifth inertial attitude relative to the inertial space, and the installation matrix of the star sensor on the auxiliary satellite and the fifth inertial attitude are used to calculate the sixth inertial attitude of the auxiliary star body relative to the inertial space; Calculating the attitude of the auxiliary satellite target relative to the auxiliary satellite body by using the fourth inertial attitude and the sixth inertial attitude; Determine the direction of the auxiliary star body relative to the second position of the auxiliary satellite using the installation matrix of the second position of the auxiliary satellite on the auxiliary satellite; The orientation of the auxiliary satellite target relative to the auxiliary satellite second position is determined by using the posture of the auxiliary satellite target relative to the auxiliary satellite body and the orientation of the auxiliary satellite body relative to the auxiliary satellite second position.

6. The method according to any one of claims 1 to 5, characterized in that: Also includes: According to the baseline data between the first position of the primary satellite and the second position of the auxiliary satellite, the three-axis turntable is controlled to follow the baseline direction to obtain the baseline measurement results in real time.

7. An intersatellite baseline measurement device based on multi-reference joint calibration, characterized in that: Located in the measurement system, the measurement system is located in the main satellite of the distributed satellite formation, the measurement system also includes: a three-axis turntable, a laser vision fusion measurement device and a star sensor; the laser vision fusion measurement device includes: a laser ranging module and a visual measurement module; the laser vision fusion measurement device is fixedly connected to the three-axis turntable, and the laser vision fusion measurement device rotates with the rotation of the three-axis turntable; the inter-satellite baseline measurement device includes: A target search unit, used for searching the auxiliary satellite target based on the three-axis turntable and the visual measurement module, so that the auxiliary satellite target is located in a designated area of ​​the field of view of the visual measurement module; A fusion measurement unit, used to obtain the baseline data between the laser vision fusion measurement device and the auxiliary satellite target obtained by the fusion measurement of the laser ranging module and the vision measurement module; the baseline data is obtained after the laser ranging module and the vision measurement module are calibrated with each other; The attitude transfer calculation unit is used to obtain the inertial attitude of the star sensor and the visual measurement module on the same reference, and perform attitude transfer in combination with the baseline data to obtain the baseline data between the first position of the primary satellite and the second position of the auxiliary satellite.

8. A measurement system, characterized in that: The measurement system is located in the main satellite of the distributed satellite formation, and the measurement system also includes: a three-axis turntable, a laser vision fusion measurement device and a star sensor; the laser vision fusion measurement device includes: a laser ranging module and a visual measurement module; the laser vision fusion measurement device is fixedly connected to the three-axis turntable, and the laser vision fusion measurement device rotates with the rotation of the three-axis turntable; The inter-satellite baseline measurement device is used to search for the auxiliary satellite target based on the three-axis turntable and the visual measurement module, so that the auxiliary satellite target is located in the specified area of ​​the field of view of the visual measurement module; obtain the baseline data between the laser vision fusion measurement device and the auxiliary satellite target obtained by the fusion measurement of the laser ranging module and the visual measurement module; the baseline data is obtained after the laser ranging module and the visual measurement module are calibrated with each other; obtain the inertial attitude of the star sensor and the visual measurement module on the same reference, combine the baseline data for attitude transfer, and obtain the baseline data between the first position of the primary satellite and the second position of the auxiliary satellite.

9. A computer device, characterized in that: The computer device includes a memory and a processor, the memory is used to store a computer program, and the processor is used to execute the computer program stored in the memory to implement the steps of any one of the methods described in claims 1-6.

10. A computer-readable storage medium, characterized in that: The storage medium stores a computer program, and when the computer program is executed by a processor, the steps of the method described in any one of claims 1 to 6 are implemented.

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