TW201425969A - Attitude data fusion method without pulsed interference - Google Patents

Abstract

The present invention provides an attitude data fusion method, in which, after each inertial attitude estimation device acquires its satellite attitude data for a plurality of inertial attitude estimation devices and before the satellite attitude data fusion is performed, one of the inertial attitude estimation devices, i.e., the planetarium, is set as the main planetarium, and the swirl error between the main satellite attitude data obtained from the main planetarium and the sub satellite attitude data obtained from other planetariums is calculated. Then, a stable error is acquired from the swirl error through a low pass filter to correct the sub satellite attitude data. When the corrected satellite attitude data obtained by the attitude data fusion method of this invention is applied to the fusion of plural satellite attitude data, especially in the conversion among fusion models of different numbers of satellite attitude data, the problem of pulsed interference can be eliminated.

Description

Attitude data fusion method without pulse interference

The invention relates to a method for merging posture data, and more specifically, it is applied to a space satellite to eliminate the fusion of multiple sets of satellite attitude data, especially when converting between different modes of satellite attitude data fusion modes. An attitude data fusion method for generating pulsed interference.

In the field of space satellites, most of the systems used to estimate the attitude of the satellite use the inertial attitude estimation device to estimate the attitude of the satellite. Here, the inertial attitude estimation device is the asteroid. In general, three asteroids mounted on a stable optical platform are responsible for providing satellite inertial attitude data corresponding to the satellite coordinate system, and these satellite inertial attitude data are generally provided in the form of quaternions. . However, the satellite attitude data provided by the three satellite cameras still need to be merged in order to be converted into the best satellite attitude data required.

In 2003, L. Roman proposed a method to best combine the satellite pose data provided by different asteroids. In this method, the satellite attitude data can be integrated and obtained in the case where the three satellite cameras provide satellite attitude data, or any two of the satellite cameras provide satellite attitude data. Although the azimuth of each asteroid is installed when the asteroid is installed, that is, the position, direction and angle of the satellite with respect to the satellite body are adjusted. In addition, except for the noise and deviation generated by the method itself, due to the measurement error on the azimuth of each asteroid, or the environmental factors interfered by the satellite in space operation, the satellite instrument Each asteroid will produce an azimuth difference due to factors such as deformation caused by itself. Therefore, the real-time satellite data fusion through this method will still generate the pulse of the attitude data when the operation of the mode of different numbers of satellite attitude data is converted. Interference situation.

In U.S. Patent No. 7,124,001, the inventor proposes a method for calculating a relative pose data between a main pose data and a sub-attribute data using a relative pose data estimation parameter, and using the relative pose data to adjust sub-pose data. To improve the satellite attitude data obtained. However, the relative attitude data obtained in this method is not optimized. However, it is not aimed at combining multiple satellite attitude data. When one of the multiple satellite instruments fails, it must be in different numbers of satellite attitude data. A solution to the pulsed interference of the pose data generated during the transition between the fusion modes is proposed.

Therefore, how to find a way to solve the deviation caused by the fusion of multiple satellite attitude data, and to solve the deformation caused by the measurement, or the deformation caused by environmental factors, etc. The azimuth difference caused by each inertial attitude estimating device, which causes the pulsed interference generated when the data fusion mode of the different amount of satellite attitude data is converted, is a problem to be solved.

Based on the above reasons, the object of the present invention is to provide a non-pulse interference attitude data fusion method, which is applied to the space satellite field, and is used for misalignment correction of satellite attitude data obtained by multiple sets of inertial attitude estimation devices, so that In the fusion of multiple sets of satellite attitude data, and between modes that fuse different numbers of satellite attitude data, there is no attitude data fusion method that generates pulse interference.

A feature of the present invention is to provide an attitude data fusion method for eliminating pulsed interference, in which a plurality of sets of inertial attitude estimation devices obtain satellite attitude data, and before performing satellite attitude data fusion, one set of inertial postures The estimation device, that is, the astrological instrument, is set as the main astrological instrument, and calculates the rotation difference between the main satellite attitude data obtained by the autonomous star image and the subsatellite attitude data obtained from other astronomical instruments, and then passes through a low pass filter. A stable difference is obtained from the rotation difference to correct the sub-satellite attitude data. The satellite attitude data corrected by the attitude data fusion method of the present invention does not generate pulse-like interference when being used for multi-group satellite attitude fusion, especially when switching between different modes of satellite attitude data fusion modes. problem.

The technical means of the present invention comprises the steps of: obtaining a corresponding number of satellite attitude data in a complex array inertial attitude estimating device; converting the satellite attitude data from the inertial attitude estimating device coordinate system to a satellite coordinate system; A set of satellite attitude data is set as a main satellite attitude data, and the remaining satellite attitude data are respectively set as a sub-satellite attitude data; and the misalignment between the sub-satellite attitude data and the main satellite attitude data is corrected. The step of misalignment correction further comprises: selecting a set of sub-satellite attitude data from the sub-satellite attitude data; calculating a rotation difference ΔQ between the main satellite attitude data and the sub-satellite attitude data; and passing the low-pass filter One of the rotational differences ΔQ is obtained as a stable difference ΔQ _f ; the obtained stability difference ΔQ _{f is} used to correct the subsatellite attitude data. Finally, the corrected sub-satellite attitude data and the main satellite attitude data are fused.

The complex array inertial attitude estimating device of the present invention can be a first star imager, a second star imager, and a third star imager. Among them, the first astronomical instrument is set as the main astrological instrument, and the above-mentioned main satellite attitude data is obtained from the main astrological instrument. In addition, one of the two sets of satellite attitude data applied to the method must include the main satellite attitude data Q ₁ obtained by the autonomous satellite image, and the other set of the satellite attitude data can be from the second satellite image or the Q ₂ or Q ₃ obtained by any of the stars in the Samsung Imager.

In addition, each of the inertial attitude estimating devices has an azimuth angle, and the misalignment corrected in the present invention refers to each inertial attitude estimating device caused by the error in the measurement when the complex array inertial attitude estimating device is installed. The misalignment caused by one azimuth difference and the misalignment caused by the complex array inertial attitude estimation device affected by environmental factors in space.

The embodiments of the present invention will be described in more detail below with reference to the drawings and the <RTIgt; </ RTI> <RTIgt; </ RTI> <RTIgt; </ RTI> <RTIgt; </ RTI> <RTIgt;

The first figure shows the flow of the attitude data fusion method according to the present invention. Cheng Tu. As shown in the first figure, the attitude data fusion method of the present invention for eliminating the pulsed interference generated when merging a plurality of sets of satellite attitude data mainly comprises three steps. First, in step S11, a plurality of sets of satellite attitude data are acquired from a complex array inertial posture estimating device installed on a satellite, where the inertial attitude estimating device is a star image device; then, in step S12, Then, the obtained multi-satellite attitude data is corrected. Finally, in step S13, the corrected satellite attitude data is merged. The steps in the preferred embodiment will be described in detail hereinafter.

The second figure shows a detailed flow chart of step S11 in accordance with a preferred embodiment of the present invention. As shown in the second figure, in the preferred embodiment, step S11 further includes three steps S111, S112, and S113. In a preferred embodiment of the present invention, the complex array inertial attitude estimating device comprises a first star imager CHU1, a second star imager CHU2, and a third star imager CHU3, wherein the first star imager CHU1 is the main star image. Here, the first star imager CHU1 set as the main star imager is the star image instrument with the most accurate measurement results among the three star instruments. Therefore, under this premise, one of the plurality of sets of satellite attitude data acquired in step S111 must be the first satellite attitude data Q ₁ obtained in the autonomous star instrument, and the remaining satellite attitude data may be separately from the first The second or third satellite attitude data Q ₂ or Q ₃ obtained by the second star imager CHU2 or the third star imager CHU3. In addition, although the satellite attitude data can be calculated by any coordinate system, in the preferred embodiment, the coordinate system of the satellite itself is used, and therefore, in step S112, the acquired satellite attitude data is obtained. Q ₁ , Q ₂ and Q ₃ are converted from the satellite coordinate system from their respective satellite image coordinate systems.

Next, in step S113, the first satellite attitude data Q ₁ obtained in the autonomous star imager CHU1 is set as the main satellite attitude data, and the second satellite image CHU2 and the third star image instrument CHU3 are obtained. Or the third satellite attitude data Q ₂ or Q _{3 is} set as the subsatellite attitude data. In this method, the main star imager CHU1 is set as the star image instrument with the most accurate measurement result. Therefore, in the subsequent misalignment correction, the main satellite attitude data Q _{1 is} mainly used, and the subsatellite attitude data Q _{2 is used.} And Q ₃ for correction.

The correction of step S12 must first select a set of sub-satellite attitude data to be performed. Therefore, the following will first explain the misalignment correction between Q ₁ and Q ₂ .

Each of the asteroids has an azimuth angle, and the misalignment corrected in the present invention is caused by the error of the measurement, and the azimuth difference of each of the inertial attitude estimating devices is caused by the installation of the complex array of asteroids. The resulting misalignment and the misalignment caused by the complex array of inertial attitude estimation devices affected by environmental factors in space. The third figure is a detailed flow chart showing step S12 in accordance with a preferred embodiment of the present invention. As shown in the third figure, in the preferred embodiment, the step S12 of correcting the satellite attitude data further includes three steps S121, S122, and S123. First, in step S121, a rotation difference ΔQ between the main satellite attitude data Q ₁ and the sub-satellite attitude data Q ₂ is calculated. Next, in step S122, a stable difference ΔQ _f is obtained from the spin difference ΔQ using a low pass filter. Among them, the stability difference ΔQ _f obtained by the low-pass filter has excluded the noise caused by temperature, satellite rotation, and other factors such as the sun, and therefore, in the next step S123, the obtained result can be directly utilized. The stability difference ΔQ _{f is} used to correct the subsatellite attitude data Q ₂ .

Although in the preferred embodiment, a low-pass filter is used to obtain a stable difference ΔQ _f from the rotational difference ΔQ, any other filter having the same effect is in the protection scope of the present invention.

The fourth figure shows a detailed flow chart of the satellite attitude data fusion performed by applying the above steps. In the above steps, another sub-satellite attitude data Q ₃ obtained from the third horoscope CHU3 and the sub-satellite attitude data Q _{2 may} be replaced, and the same steps are repeated to obtain a corrected sub-routine. Satellite attitude data Q ₃ '. The corrected subsatellite pose data Q ₂ ' and Q ₃ ' obtained through steps S121, S122, and S123 can be used in step S13 to perform data fusion with the main satellite attitude data Q ₁ to obtain a complete satellite. Attitude information.

The data fusion method used in the preferred embodiment is the method of "best combination of satellite pose data provided by different asteroids" as disclosed by L. Roman. Since the method is a conventional method and it is not the feature of the present invention, the content of the method is not described in detail in the present specification.

The fifth graph is the assumed value of the two test groups, which assumes the misalignment values of the three satellites in three directions. In order to verify the reliability of the pose data fusion method of the present invention, the numerical values shown in the fifth figure will be used to compare the results of the data fusion of the satellite pose data corrected by the pose data fusion method of the present invention, and The data of the satellite attitude data corrected by the attitude data fusion method of the present invention is used for data fusion.

The total attitude error of the satellite attitude data after data fusion can be calculated by the following formula:

Among them, roll_err is the rolling error, pitch_err is the pitch error, yaw_err is the yaw error, and RSI_FOV is 2 degrees.

The sixth figure shows the total attitude error of the satellite attitude data directly based on the value of the first test group and without the attitude data fusion method of the present invention; the eighth figure shows the second test according to the second test. The value of the group, and also the total attitude error of the satellite attitude data directly subjected to data fusion without the attitude data fusion method of the present invention. Because the satellite image may be exposed to the strong light emitted by a planet such as the sun during the operation of the satellite, the star instrument will be disabled. At this time, the timely satellite attitude fusion system will switch from the mode of combining three satellite attitude data to the mode of combining two satellite attitude data; in the process of switching, it will be displayed as shown in the sixth figure and the eighth figure. The pulsed error, and the object of the present invention is to eliminate these pulsed errors.

The pose data fusion method according to the preferred embodiment of the present invention is written as an algorithm using C++ language, and the misalignment between the three sets of satellite pose data Q ₁ , Q ₂ and Q ₃ is corrected by a computer program. The seventh figure shows the total attitude error of the satellite attitude data according to the value of the first test group and corrected by the attitude data fusion method of the present invention; the ninth figure shows the second test group according to the second test group. The value of the total attitude error of the satellite attitude data after the data fusion is also corrected by the attitude data fusion method of the present invention. As shown in the seventh and ninth diagrams, the total error of the satellite pose data corrected by the pose data fusion method of the present invention after data fusion does not appear as shown in the sixth and eighth figures. Pulsed error. Therefore, it can be known from the simulation results that the attitude data fusion method according to the present invention can effectively eliminate the pulse type interference generated when the data of the plurality of sets of satellite poses is integrated.

The tenth figure shows a satellite attitude estimation method. The method shown in the figure is a satellite attitude estimation method 3 according to the contents of Taiwan Patent Application No. 97119874, which can estimate the attitude of the satellite by using the information provided by the gyroscope or the star imager. As shown in the tenth figure, after acquiring the data 21 of the asteroid instrument and before performing the satellite attitude estimation 3, the attitude data fusion method 210 of the present invention can be used to fuse the satellite attitude data obtained from the asteroid instrument. The results are optimized to obtain a more accurate estimate of the attitude of the satellite.

In summary, the attitude data fusion method provided by the present invention can calculate the misalignment value between any pair of asteroids, and apply the calculated misplacement value to the satellite attitude data in real time to use Roman. Prior to the method of combining multiple sets of satellite attitude data, the misalignment between the asteroids is corrected. The satellite attitude data corrected by the attitude data fusion method can avoid the pulse interference caused by the conversion of the data fusion mode.

The above description is only for the preferred embodiment of the present invention, and those skilled in the art can make other improvements according to the above description, but these changes are still It is within the spirit of the invention and the scope of the patents defined below.

CHU1‧‧‧First Star Imager

CHU2‧‧‧Second Star Imager

CHU3‧‧‧ Third Star Imager

Q ₁ ‧‧‧First satellite attitude data

Q ₂ ‧‧‧Second satellite attitude data

Q ₃ ‧‧‧3rd satellite attitude data

Q ₂ '‧‧‧corrected second satellite attitude data

Q ₃ '‧‧‧corrected third satellite attitude data

△Q‧‧‧rotation difference

△Q _f ‧‧‧stable stability

S11 S111 S112 S113 S12 S121 S122 S123 S13 21 210 22 3‧‧‧Steps

The first figure is a flow chart showing a posture data fusion method according to the present invention; the second figure is a detailed flow chart showing step S11 according to a preferred embodiment of the present invention; and the third figure is a display according to a preferred embodiment of the present invention. Detailed flow chart of step S12; fourth figure is a detailed flow chart showing satellite attitude data fusion according to a preferred embodiment of the present invention; fifth figure is assuming that three star instruments of two test groups are assumed in three directions The misalignment value; the sixth figure shows the total attitude error of the satellite attitude data directly based on the value of the first test group and without the attitude data fusion method of the present invention; the seventh figure shows the basis The value of the first test group, and the total attitude error of the satellite attitude data after data fusion by the attitude data fusion method of the present invention; the eighth figure shows the value according to the second test group, and has not been subjected to the present invention. The attitude data fusion method directly performs the total attitude error of the satellite attitude data of the data fusion; the ninth figure shows the value according to the second test group. And after the posture information of the present invention for the total fusion of satellite attitude data the attitude information of the error correction method after fusion; The tenth figure shows a satellite attitude estimation method.

S11‧‧‧ obtained multiple sets of satellite attitude data

S12‧‧‧Correct misalignment between multiple sets of satellite attitude data

S13‧‧‧Harmonized corrected satellite attitude data

Claims (8)

A non-pulse interference attitude data fusion method for eliminating pulsed interference generated by converting a plurality of satellite attitude data fusion modes when merging data of a plurality of satellite attitudes, the attitude data fusion method comprising the following steps Obtaining a corresponding number of satellite attitude data in the complex array inertial attitude estimation device; setting one of the satellite attitude data as a main satellite attitude data, and setting the remaining satellite attitude data as a sub-satellite attitude data; Correcting a misalignment between the sub-satellite attitude data and the main satellite attitude data; and merging the corrected sub-satellite attitude data and the main satellite attitude data. According to the attitude data fusion method of claim 1, wherein the step of correcting the misalignment between the sub-satellite posture data and the main satellite attitude data further comprises: from the sub-satellite posture data Select a set of subsatellite pose data. The attitude data fusion method according to claim 2, wherein the correcting the misalignment between the sub-satellite attitude data and the main satellite attitude data further comprises: calculating the main satellite attitude data and the sub-satellite A rotation difference ΔQ between the attitude data; a filter to obtain a stability difference ΔQ _{f of} the rotation difference ΔQ; and the obtained stability difference ΔQ _f to correct the sub-satellite attitude data. The attitude data fusion method according to claim 3, wherein the filter is a low pass filter. The attitude data fusion method according to claim 1, wherein after acquiring the satellite attitude data, the satellite attitude data is converted from the inertial attitude estimation device coordinate system to the satellite coordinate system. The attitude data fusion method according to claim 1, wherein the complex array inertial posture estimating device is a first star imager CHU1, a second star imager CHU2, and a third star imager CHU3, wherein the The first astrological instrument is the main astrological instrument. According to the attitude data fusion method described in claim 7, wherein one of the satellite attitude data obtained must be the first satellite attitude data Q ₁ obtained in the autonomous star instrument, and the other group The satellite attitude data may be the second satellite attitude data Q ₂ or the third satellite attitude data Q ₃ obtained from the second asteroid or the third satellite. The attitude data fusion method according to claim 1, wherein the complex array inertial posture estimating device has an azimuth angle, and the misalignment refers to an azimuth difference of each inertial posture estimating device. .