Satellite Signal Source Optimal Point Calibration and Positioning Method, Device, Equipment, and Storage Medium

Abstract

The present application relates to a method, device, equipment and storage medium for correcting and positioning the optimal point of a satellite signal source. The method includes: obtaining a gyro drift estimation model of a celestial gyroscope, constructing an optimization model by maximizing the denominator term of the gyro drift estimation model to minimize the gyro drift rounding error; solving the optimization model according to the earth's angular velocity of rotation and the Schuler frequency of an inertial navigation system to obtain the maximum point of the function corresponding to the denominator term; obtaining an initial value point set according to the maximum points within the first two earth periods of the voyage, using the Newton iteration method to solve the exact value of the initial value point in the initial value point set that is close to the single-point correction time period, calculating the exact maximum point within the single-point correction time period according to the exact value and the period of the first derivative function of the denominator term, and taking the exact maximum point as the optimal gyro correction point; using the optimal gyro correction point for single-point correction. Using this method can improve the navigation accuracy of a rotation modulation inertial navigation system.

Description

Technical Field

[0001] The present application relates to the technical field of inertial navigation, and particularly to a method, device, equipment and storage medium for correcting and positioning the optimal point of a satellite signal source. Background Art

[0002] With the development of inertial navigation technology, rotation modulation inertial navigation technology has emerged. Rotation modulation inertial navigation periodically changes the sensitive axis direction of inertial devices, uniformly modulating the errors of inertial devices to 0 within a certain period, which can effectively reduce the influence of errors on navigation accuracy, especially showing significant advantages in improving the navigation accuracy during long-term operation.

[0003] In a rotation modulation inertial navigation system, the drift of the vertical gyroscope is the main error source. The drift of the vertical gyroscope refers to the non-ideal rotation phenomenon of the gyroscope along the vertical axis direction. Due to the existence of disturbing torques, it is divided into two categories: systematic and random. Although its numerical magnitude is very small, due to the limited suppression ability of rotation modulation on it, the errors will continuously accumulate, thus having a significant impact on the navigation accuracy during long-term operation, such as causing the longitude error to slowly diverge over time.

[0004] Currently, for the treatment of the drift of the vertical gyroscope, the traditional method is to obtain its approximate value through long-term filtering estimation. This method requires long-term collection of longitude and latitude observation values, and uses filtering algorithms to remove noise interference and extract the drift information of the vertical gyroscope. However, in practical applications, affected by factors such as task time limitations and changes in observation conditions (such as signal occlusion, equipment failure, etc.), it is difficult to continuously and stably obtain long-term longitude and latitude observation values. This makes the traditional method inefficient, unable to meet the actual needs, difficult to accurately estimate the drift amount of the vertical gyroscope, and further affects the navigation accuracy of the rotation modulation inertial navigation system. Summary of the Invention

[0005] Based on this, it is necessary to provide a method, device, equipment and storage medium for correcting and positioning the optimal point of a satellite signal source in view of the above technical problems.

[0006] A method for correcting and positioning the optimal point of a satellite signal source, the method comprising:

[0007] Obtain a gyro drift estimation model of a vertical gyroscope, and construct an optimization model by maximizing the denominator term of the gyro drift estimation model to minimize the gyro drift rounding error;

[0008] Solve the optimization model according to the angular velocity of the Earth's rotation and the Schuler frequency of the inertial navigation system to obtain the maximum point of the function corresponding to the denominator term;

[0009] An initial value point set is obtained based on the maximum value points within the first two Earth cycles before the voyage. The Newton iteration method is used to solve for the exact value of the initial value point in the initial value point set that is close to the single-point calibration time period. Based on the exact value and the period of the first derivative function of the denominator term, the exact maximum value point within the single-point calibration time period is calculated, and the exact maximum value point is used as the optimal gyro calibration point;

[0010] Single-point calibration is performed using the optimal gyro calibration point to obtain calibrated navigation and positioning data.

[0011] In one embodiment, solving for the maximum value point of the function corresponding to the denominator term in the optimization model based on the Earth's angular velocity of rotation and the Schuler frequency of the inertial navigation system includes: calculating the first derivative function of the denominator term of the gyro drift estimation model with respect to time, and substituting the Earth's angular velocity of rotation and the Schuler frequency of the inertial navigation system into the first derivative function; calculating the maximum value point of the function corresponding to the denominator term based on the first derivative function.

[0012] In one embodiment, using the Newton iteration method to solve for the exact value of the initial value point in the initial value point set that is close to the single-point calibration time period includes: obtaining a preset single-point calibration time period; using the initial value point in the initial value point set that is close to the single-point calibration time period as the initial solution, and using the Newton iteration method to iteratively solve the equation when the first derivative function is 0 until the iteration stop condition is met, and then outputting the exact solution.

[0013] In one embodiment, using the optimal gyro calibration point to perform single-point calibration to obtain calibrated navigation and positioning data includes: obtaining the real-time data of the celestial gyroscope at the optimal gyro calibration point, performing data validity judgment on the real-time data according to a preset data validity criterion, and if the real-time data is valid, performing celestial gyro drift estimation on the real-time data and compensating for the positioning error caused thereby to obtain the output calibrated navigation and positioning data.

[0014] In one embodiment, the method further includes: performing data validity judgment on the real-time data according to a preset data validity criterion, and if the real-time data is invalid, using satellite data for position reset.

[0015] In one embodiment, the validity criterion includes condition number judgment, latitude and longitude consistency check, and outlier detection.

[0016] In one embodiment, the gyro drift estimation model is:

[0017] ;

[0018] wherein, is the celestial gyro drift, is the latitude change amount, is the latitude, is the angular velocity of the Earth's rotation, is the time, is the longitude change amount, is the longitude, is the Schuler frequency of the inertial navigation system.

[0019] A satellite signal source optimal point correction and positioning device, the device includes:

[0020] An optimization model construction module, used to obtain the gyro drift estimation model of the celestial gyroscope, construct an optimization model by maximizing the denominator term of the gyro drift estimation model to minimize the gyro drift rounding error;

[0021] An optimization model solving module, used to solve the optimization model according to the angular velocity of the Earth's rotation and the Schuler frequency of the inertial navigation system to obtain the maximum point of the function corresponding to the denominator term;

[0022] A correction point optimization module, used to obtain an initial value point set according to the maximum points belonging to the first two Earth cycles of the voyage, use the Newton iteration method to solve the exact value of the initial value point close to the single-point correction time period in the initial value point set, and calculate the exact maximum point in the single-point correction time period according to the exact value and the period of the first derivative function of the denominator term, and use the exact maximum point as the optimal gyro correction point;

[0023] A positioning correction module, used to perform single-point correction using the optimal gyro correction point to obtain corrected navigation and positioning data.

[0024] A computer device, including a memory and a processor, the memory stores a computer program, and when the processor executes the computer program, the following steps are implemented:

[0025] Obtain the gyro drift estimation model of the celestial gyroscope, construct an optimization model by maximizing the denominator term of the gyro drift estimation model to minimize the gyro drift rounding error;

[0026] Solve the optimization model according to the angular velocity of the Earth's rotation and the Schuler frequency of the inertial navigation system to obtain the maximum point of the function corresponding to the denominator term;

[0027] Obtain an initial value point set according to the maximum points belonging to the first two Earth cycles of the voyage, use the Newton iteration method to solve the exact value of the initial value point close to the single-point correction time period in the initial value point set, and calculate the exact maximum point in the single-point correction time period according to the exact value and the period of the first derivative function of the denominator term, and use the exact maximum point as the optimal gyro correction point;

[0028] Perform single-point calibration using the optimal gyro calibration point to obtain calibrated navigation and positioning data.

[0029] A computer-readable storage medium stores a computer program thereon. When the computer program is executed by a processor, the following steps are implemented:

[0030] Obtain a gyro drift estimation model of a celestial gyroscope, construct an optimization model by maximizing the denominator term of the gyro drift estimation model to minimize the gyro drift rounding error;

[0031] Solve the optimization model according to the angular velocity of the Earth's rotation and the Schuler frequency of the inertial navigation system to obtain the maximum point of the function corresponding to the denominator term;

[0032] Obtain an initial value point set based on the maximum points within the first two Earth cycles of the voyage. Use the Newton iteration method to solve the exact value of the initial value point in the initial value point set that is close to the single-point calibration time period. Calculate the exact maximum point within the single-point calibration time period according to the exact value and the period of the first derivative function of the denominator term, and use the exact maximum point as the optimal gyro calibration point;

[0033] Perform single-point calibration using the optimal gyro calibration point to obtain calibrated navigation and positioning data.

[0034] The above satellite signal source optimal point calibration and positioning method, device, equipment, and storage medium construct an optimization model by maximizing the denominator term of the gyro drift estimation model, which can minimize the gyro drift rounding error from the calculation source, avoid accuracy loss caused by numerical processing, ensure the reliability of the estimated value, solve the optimization model in combination with the angular velocity of the Earth's rotation and the Schuler frequency of the inertial navigation system, can accurately determine the maximum point of the denominator term function, get rid of the dependence on long-term observation data, select the maximum points within the first two Earth cycles of the voyage to determine the initial value point set, and use the Newton iteration method to accurately solve, which can quickly locate the optimal gyro calibration point, greatly improve the calibration efficiency, use the optimal gyro calibration point to perform single-point calibration, can effectively suppress the accumulation of celestial gyro drift error, avoid the divergence of longitude error, significantly improve the navigation accuracy of the rotation modulation inertial navigation system, and meet the actual needs of satellite long-term high-precision navigation. Description of the Drawings

[0035] Figure 1 It is a schematic flowchart of the satellite signal source optimal point calibration and positioning method in an embodiment;

[0036] Figure 2 It is a schematic curve diagram of the first derivative function of the denominator term in an embodiment;

[0037] Figure 3 It is a schematic curve diagram of the denominator term in an embodiment;

[0038] Figure 4 Schematic diagram of the positioning and calibration process in an embodiment;

[0039] Figure 5 Schematic diagram of the calibration effect of the optimal point 1 from the satellite signal source in an embodiment. Among them, Figure 5 (a) Schematic diagram of the latitude error of the optimal point 1 of the satellite signal source, Figure 5 (b) Schematic diagram of the longitude error of the optimal point 1 of the satellite signal source, Figure 5 (c) Schematic diagram of the positioning error of the optimal point 1 of the satellite signal source;

[0040] Figure 6 Schematic diagram of the point selection distribution of the estimated value of the INS gyro drift in an embodiment;

[0041] Figure 7 Schematic diagram of the effect of the mean point of the gyro drift estimation in the first stage in an embodiment. Among them, Figure 7 (a) Latitude error of the mean point 1 of the INS drift estimation, Figure 7 (b) Longitude error of the mean point 1 of the INS drift estimation, Figure 7 (c) Positioning error of the mean point 1 of the INS drift estimation;

[0042] Figure 8 Block diagram of the structure of the calibration and positioning device for the optimal point of the satellite signal source in an embodiment;

[0043] Figure 9 Internal structure diagram of a computer device in an embodiment. Detailed implementation manners

[0044] In order to make the objectives, technical solutions and advantages of the present application clearer, the present application will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0045] For rotationally modulated inertial navigation, the main error is the drift of the vertical gyro. The numerical magnitude of the vertical gyro drift is very small, and the resulting latitude and longitude errors are not large. The traditional method is to obtain an approximate value through long-term filtering estimation, which requires long-term latitude and longitude observation values and is difficult to meet in practice.

[0046] In one embodiment, as Figure 1 shown, a method for calibrating and positioning the optimal point of a satellite signal source is provided, including the following steps:

[0047] Step 102, obtain a gyro drift estimation model of the vertical gyroscope, and construct an optimization model by maximizing the denominator term of the gyro drift estimation model to minimize the gyro drift rounding error.

[0048] Round-off error is the error generated during numerical calculations due to rounding operations on numbers. In the gyro drift estimation model, when the denominator term takes on a very large value, the denominator term becomes much larger relative to the numerator. The gyro drift estimation model is as follows:

[0049] .

[0050] At this time, due to small changes in the numerator and denominator terms caused by factors such as rounding operations, the impact on the entire fraction (i.e., the gyro drift estimated value) will be even smaller. Therefore, the round-off error of the estimated gyro drift is minimized. Based on this, to minimize the round-off error in the estimation process, an optimization model is constructed, and its optimization goal is to maximize the denominator term of the gyro drift estimation model.

[0051] It can be understood that by optimizing the mathematical model, the round-off error is reduced from the source of calculation, improving the accuracy of the gyro drift estimated value and providing a more reliable data basis for subsequent positioning correction.

[0052] Step 104: Solve the optimization model according to the Earth's angular velocity of rotation and the Schuler frequency of the inertial navigation system to obtain the maximum point of the function corresponding to the denominator term.

[0053] By maximizing the denominator, the estimation error caused by finite-precision calculations can be significantly reduced, and the robustness of gyro drift parameter identification can be improved. From the gyro drift estimation model, the maximum value of the denominator can be approximately regarded as the optimal gyro correction point. In step 106, the optimal gyro correction point is further optimized to improve the correction accuracy.

[0054] Step 106: Obtain the set of initial value points based on the maximum points within the first two Earth cycles of the voyage. Use the Newton iteration method to solve the exact value of the initial value point in the set of initial value points that is close to the single-point correction time period. Calculate the exact maximum point within the single-point correction time period according to the exact value and the period of the first derivative function of the denominator term, and use the exact maximum point as the optimal gyro correction point.

[0055] The maximum points within the first two Earth cycles of the voyage contain important information related to the initial operating state of the satellite. Selecting the set of initial value points from them can provide a suitable starting value for subsequent accurate solution. The Newton iteration method is an efficient numerical iteration algorithm used to solve the roots or extreme values of a function. By using it to solve the exact value of the initial value point close to the single-point correction time period and then combining with the period of the periodic function to calculate the exact maximum point within the single-point correction time period.

[0056] It can be understood that the determined optimal gyro correction point is obtained by comprehensively considering the characteristics of the initial stage of satellite operation and the requirements of the single-point correction time period. Compared with the traditional method, it does not require long-term waiting for data accumulation to determine the correction point, can quickly and accurately find the point most suitable for gyro correction in the current mission stage, and greatly improves the efficiency and accuracy of positioning correction.

[0057] Step 108, perform single-point correction using the optimal gyro correction point to obtain the corrected navigation and positioning data.

[0058] After determining the optimal gyro correction point, use the data at this point to perform single-point correction. By correcting the celestial gyro drift, the correction of satellite positioning is ultimately achieved.

[0059] In the above satellite signal source optimal point correction and positioning method, an optimization model is constructed by maximizing the denominator term of the gyro drift estimation model, which can minimize the gyro drift rounding error from the calculation source, avoid accuracy loss caused by numerical processing, ensure the reliability of the estimated value, solve the optimization model in combination with the earth's angular velocity of rotation and the Schuler frequency of the inertial navigation system, can accurately determine the maximum point of the denominator term function, get rid of the dependence on long-term observation data, select the maximum points within the first two earth cycles of the voyage to determine the set of initial points, and use the Newton iteration method to accurately solve, which can quickly locate the optimal gyro correction point, greatly improve the correction efficiency, use the optimal gyro correction point to implement single-point correction, can effectively suppress the accumulation of celestial gyro drift error, avoid the divergence of longitude error, significantly improve the navigation accuracy of the rotation modulation inertial navigation system, and meet the actual needs of satellite long-term high-precision navigation.

[0060] In one embodiment, solving the optimization model according to the earth's angular velocity of rotation and the Schuler frequency of the inertial navigation system to obtain the maximum point of the function corresponding to the denominator term includes: calculating the first-order derivative function of the denominator term of the gyro drift estimation model with respect to time, and substituting the earth's angular velocity of rotation and the Schuler frequency of the inertial navigation system into the first-order derivative function; calculating the maximum point of the function corresponding to the denominator term according to the first-order derivative function.

[0061] In this embodiment, denote the denominator of the gyro drift estimation model as , Take the derivative of :

[0062] ;

[0063] Let , there is:

[0064] ;

[0065] It can be calculated that , let , that is:

[0066] ;

[0067] Its curve is as Figure 2 shown. The solution of the above equation needs to satisfy simultaneously, and then this solution can be considered as the maximum point. That is:

[0068] ;

[0069] Thus, the set of maximum points of the denominator is obtained.

[0070] In one embodiment, using the Newton iteration method to solve the exact value of the initial point in the set of initial points that is close to the single-point calibration time period includes: obtaining the pre-set single-point calibration time period; taking the initial point in the set of initial points that is close to the single-point calibration time period as the initial solution, and using the Newton iteration method to iteratively solve the equation when the first derivative function is 0 until the iteration stop condition is satisfied, and then outputting the exact solution.

[0071] In this embodiment, through a series of steps, including obtaining the set of initial points based on the maximum points in the first two earth cycles of the voyage, using the Newton iteration method to solve the exact value of the initial point close to the single-point calibration time period, and then determining the optimal gyro calibration point. It can calculate the optimal calibration moment online. Conducting damping single-point calibration at this moment can make the calibration effect reach the best, effectively reducing the influence of the celestial gyro drift error on the navigation accuracy of the rotation modulation inertial navigation system, and improving the accuracy and reliability of the positioning calibration.

[0072] Specifically, the implementation of the single-point calibration time period is 50% to 80% of the voyage, 150 hours to 220 hours. In order to calculate the optimal point of the single-point calibration time period in advance, calculate the optimal point in the first two earth cycles of the voyage, and use the period approximation of to deduce the optimal point within 150 hours to 220 hours.

[0073] The first two earth cycles of the voyage are 48 hours, and converting x is from 0 to 12.6. According to the curve, select 4 initial points, and from these four initial points, select those that satisfy the second derivative less than 0, and 2 minimum points can be deleted. Finally, obtain the initial points as 4.4 and 10.9.

[0074] Since the period approximation of is , the amplitude increases by every other cycle. The closer the initial point is to 150 hours to 220 hours, the smaller the error in deducing the optimal point. Take the initial point

[0075] ;

[0076] The solution is , where represents the number of iterations. The optimal points within 150 hours to 220 hours are x plus respectively, and when converted into time, they are respectively. For convenience of description, these three points are called calculated optimal points 1, 2, and 3.

[0077] In one embodiment, single-point calibration is performed using the optimal gyro calibration point, and the calibrated navigation and positioning data obtained includes: obtaining the real-time data of the celestial gyroscope at the optimal gyro calibration point, judging the data validity of the real-time data according to the preset data validity criterion. If the real-time data is valid, then estimating the celestial gyro drift of the real-time data and compensating for the positioning error caused thereby, and obtaining the output navigation and positioning data after calibration processing.

[0078] In this embodiment, traditional filtering estimation requires continuous multi-frame long-time observations to accurately estimate the celestial gyro drift, while the present invention calculates an approximate value of the celestial gyro drift by obtaining an analytical solution. Compared with the traditional method, the calculation time is greatly shortened, and it can quickly complete the calculations related to gyro drift in the case of limited satellite observation data (only the observation quantity at one point and one moment), meet the requirements for calculation speed in practical applications, and improve the system response efficiency.

[0079] As Figure 4 shown in the schematic flow diagram of positioning calibration, in the figure, accel represents the accelerometer, gyro represents the gyroscope, is the external reference position, is the external reference speed, is the external reference altitude, is the damping horizontal position, is the damping composite position, is the damping speed, is the damping altitude, is the inertial navigation solution speed, is the inertial navigation solution position, is the inertial navigation direction cosine matrix, is the positioning error caused by the estimated gyro drift calculated after substituting the estimated gyro drift into the inertial navigation error calculation model, After the inertial navigation positioning output offsets the positioning error caused by the estimated gyro drift, a more accurate estimated value closer to the true value is obtained. Specifically, the best gyro correction point is used for damped single-point calibration. After the damped single-point calibration, according to the relevant data and models in the calibration process, the celestial gyro drift error is estimated, substituted into the inertial navigation error calculation model, and the positioning error caused by the celestial gyro drift error is calculated in real time. Output correction is used to compensate the navigation positioning parameters output by the inertial navigation calculation to achieve positioning correction.

[0080] In one embodiment, the method further includes: judging the data validity of the real-time data according to the preset data validity criterion. If the real-time data is invalid, the satellite data is used for position reset.

[0081] In this embodiment, this process reduces the influence of environmental interference on the data, provides a high-quality data basis for subsequent calculation of the theoretical and actual gyro drift estimated values, and further ensures the accuracy and stability of the single-point calibration.

[0082] In one embodiment, the validity criterion includes condition number judgment, latitude and longitude consistency check, and outlier detection.

[0083] In one embodiment, the gyro drift estimation model is:

[0084] ;

[0085] Wherein, is the celestial gyro drift, is the latitude change, is the latitude, is the angular velocity of the earth's rotation, is the time, is the longitude change, is the longitude, is the Schuler frequency of the inertial navigation system.

[0086] As Figure 3 shown by the curve of the denominator y, within the range of 150 hours to 220 hours, 3 maximum value points can be selected, and the optimal point obtained according to the drawing is called the actual optimal point. By comparing the specific times of the calculated optimal point and the actual optimal point, it is found that the differences between them are , and the deviation is about 10 minutes. Taking the satellite navigation as the reference signal, comparing the error statistical effects of the calculated optimal point and the actual optimal point, as shown in Table 1.

[0087] Table 1 Comparison of the effects of the optimal correction points

[0088]

[0089] As can be seen from Table 1, the effects of calculating the optimal points and the actual optimal points are consistent. It shows that by using periodicity, the optimal points can be calculated in advance. For the convenience of description, the calculated optimal points 1, 2, and 3 are simply referred to as optimal points 1, 2, and 3.

[0090] It can be understood that in addition to the widely used satellite signal sources, the signal sources used in the method of the present invention can also be semi-submerged buoy signal sources, radio signal sources or underwater acoustic signal sources. The present invention takes the ocean as the test environment. The entire ocean test mainly includes acoustic positioning, satellite positioning, radio / acoustic positioning, satellite / underwater acoustic and semi-submerged buoy. Five signal sources are used to verify the calibration effect at the pre-calculated optimal points. The accuracies of different signal sources are comparable and at the same order of magnitude. The smaller the signal source error, the better the accuracy improvement effect. Only the verification results of the satellite signal source are listed below. If there is no test data for a certain signal source at the optimal point, satellite data plus noise is used for simulation, and the simulation is marked with " " at the optimal point.

[0091] Based on the pre-calculated optimal points, the satellite signal source is used for verification. Through theoretical calculation, there are three optimal calibration points in the time period from 150 hours to 220 hours. The calibration effect of the optimal point 1 of the satellite signal source is as Figure 5 shown, where Figure 5 (a) is the schematic diagram of the latitude error of the optimal point 1 of the satellite signal source, Figure 5 (b) is the schematic diagram of the longitude error of the optimal point 1 of the satellite signal source, Figure 5 and (c) is the schematic diagram of the positioning error of the optimal point 1 of the satellite signal source. It can be seen from Figure 5 that the maximum value of the pure inertial navigation positioning error is 2.0 n mile. After calibration at calibration point 1, the maximum value of the damped inertial navigation positioning error is reduced from 1.71 n mile to 0.97 n mile. The root mean square of the errors after calibration point 1 is calculated. The root mean squares of the pure inertial navigation, damped and damped single-point calibration are 1.16 n mile, 1.14 n mile and 0.46 n mile respectively. The error statistical characteristics after calibration point 1 show that the accuracy of the damped single-point calibration can effectively improve the inertial navigation positioning accuracy. The calibration effects of the second and third calibration points are similar to those of the first calibration point. The error statistical results after the calibration points are shown in Table 2:

[0092] Table 2 Calibration effect of the optimal point of the satellite signal source

[0093]

[0094] The following verifies through measured data that the effect of the optimal point is better than that of other points. Since there are many other points except the optimal point, representative points are selected for comparison. Because the more accurate the gyro drift estimate value is, the better the calibration effect is, points are selected according to the maximum, minimum, and mean of the gyro drift estimate. For the satellite signal source, within each time period, points are selected according to the maximum, minimum, and mean of the gyro drift estimate value and compared with the optimal point. The distribution of each point is as Figure 6 shown, where the effect of the mean point of the gyro drift estimate in the first segment is as Figure 7 shown, where Figure 7 (a) is the latitude error of the mean point 1 of the satellite navigation drift estimate, Figure 7 (b) is the longitude error of the mean point 1 of the satellite navigation drift estimate, Figure 7 (c) is the positioning error of the mean point 1 of the satellite navigation drift estimate. It can be seen that the calibration effect of the point obtained according to the mean of the drift estimate of the satellite navigation is feasible, and the effects of the second and third segments are similar to that of the first segment. The effects of each point are shown in Table 3, verifying that the calibration effect of the optimal point is better than that of other points.

[0095] Table 3 Comparison of the effects of the representative points and the optimal point of the satellite navigation drift estimate

[0096]

[0097] Due to space limitations, only the satellite signal source is used for illustration. The measured data of different signal sources show that the calibration effect of the optimal point is better than that of other points.

[0098] In a specific embodiment, the single-point calibration algorithm is executed at three places on the entire track to test the positioning error correction effect. The first single-point calibration is performed using the semi-submersible buoy radio positioning information; the second single-point calibration is performed using the semi-submersible buoy satellite positioning information; the third point selects the moment 48 hours before the end of the voyage and performs calibration using the satellite positioning information. The positioning error improvement effects of the three single-point calibrations are shown in Table 4. The positioning error of the three single-point calibrations is improved by 50.6% compared with the damping and pure inertial navigation.

[0099] Table 4 Comparison of the positioning error improvement effects of the three single-point calibrations

[0100]

[0101] The object of the percentage increase in the table is the root mean square of the damping single-point calibration:

[0102] Relative increase compared with pure inertial navigation = (pure inertial navigation root mean square - damping single-point calibration root mean square) / pure inertial navigation root mean square × 100%;

[0103] Relative increase compared with damping = (damping root mean square - damping single-point calibration root mean square) / damping root mean square × 100%;

[0104] The method of the present invention significantly improves the calibration efficiency compared with the traditional method. The index of the single-point calibration time less than 10 seconds is verified. Here, the single-point calibration time can be divided into three parts:

[0105] 1) Judge whether the moment corresponding to the single-point position signal can be used for calibration. This part takes about 0.1 second;

[0106] 2) If the moment is available, use the data in the 8 seconds after this moment to judge the data validity, perform consistency analysis on the 8-second data. If the consistency analysis is satisfied, it is considered that the position signal of this point is valid, and the last 1 second of the 8-second data is taken as the calibration data. This part takes about 8 seconds;

[0107] 3) If the data meets the consistency requirements, estimate the drift of the celestial gyro according to the single-point position signal, and calculate the time from when the position signal enters the inertial navigation error estimation module to when the estimated value of the celestial gyro drift is calculated. This part takes about 0.2 second.

[0108] The single-point calibration time is the sum of the times of these three parts. The calculation times of three single-point calibrations during the actual flight are shown in Table 5. The times of the three single-point calibrations are all less than 10 seconds, meeting the technical indicators.

[0109] Table 5 Calibration Time

[0110]

[0111] It should be understood that although Figure 1 the steps in the flowchart of Figure 1 are shown in sequence according to the arrows, these steps are not necessarily executed in the order indicated by the arrows. Unless there is a clear indication in this article, the execution of these steps has no strict order limit, and these steps can be executed in other orders. Moreover,

[0112] In one embodiment, as Figure 8 shown, a satellite signal source optimal point calibration and positioning device is provided, including:

[0113] An optimization model construction module 802, configured to obtain a gyro drift estimation model of the celestial gyroscope, construct an optimization model by maximizing the denominator term of the gyro drift estimation model to minimize the gyro drift rounding error;

[0114] The optimization model solving module 804 is used to solve the optimization model according to the angular velocity of the Earth's rotation and the Schuler frequency of the inertial navigation system, and obtain the maximum point of the function corresponding to the denominator term;

[0115] The correction point optimization module 806 is used to obtain the initial value point set according to the maximum points within the first two Earth cycles of the voyage, solve the exact value of the initial value point close to the single-point correction time period in the initial value point set by using the Newton iteration method, calculate the exact maximum point within the single-point correction time period according to the exact value and the period of the first derivative function of the denominator term, and use the exact maximum point as the optimal gyro correction point;

[0116] The positioning correction module 808 is used to perform single-point correction by using the optimal gyro correction point to obtain the corrected navigation and positioning data.

[0117] In one embodiment, solving the optimization model according to the angular velocity of the Earth's rotation and the Schuler frequency of the inertial navigation system to obtain the maximum point of the function corresponding to the denominator term includes: calculating the first derivative function of the denominator term of the gyro drift estimation model with respect to time, and substituting the angular velocity of the Earth's rotation and the Schuler frequency of the inertial navigation system into the first derivative function; calculating the maximum point of the function corresponding to the denominator term according to the first derivative function.

[0118] In one embodiment, solving the exact value of the initial value point close to the single-point correction time period in the initial value point set by using the Newton iteration method includes: obtaining the preset single-point correction time period; using the initial value point close to the single-point correction time period in the initial value point set as the initial solution, and iteratively solving the equation when the first derivative function is 0 by using the Newton iteration method until the iteration stop condition is satisfied, and then outputting the exact solution.

[0119] In one embodiment, performing single-point correction by using the optimal gyro correction point to obtain the corrected navigation and positioning data includes: obtaining the real-time data of the celestial gyro at the optimal gyro correction point, judging the data validity of the real-time data according to the preset data validity criterion, if the real-time data is valid, then estimating the celestial gyro drift of the real-time data and compensating the positioning error caused, and obtaining the output corrected navigation and positioning data.

[0120] In one embodiment, it further includes: judging the data validity of the real-time data according to the preset data validity criterion, if the real-time data is invalid, then using satellite data for position reset.

[0121] In one embodiment, the validity criterion includes condition number judgment, longitude and latitude consistency check, and outlier detection.

[0122] In one embodiment, the gyro drift estimation model is:

[0123] ;

[0124] Among them, is the drift of the celestial gyroscope, is the latitude change amount, is the latitude, is the angular velocity of the Earth's rotation, is the time, is the longitude change amount, is the longitude, is the Schuler frequency of the inertial navigation system.

[0125] For the specific limitations of the satellite signal source optimal point calibration positioning device, reference can be made to the limitations on the satellite signal source optimal point calibration positioning method in the above text, which will not be elaborated here. Each module in the above satellite signal source optimal point calibration positioning device can be implemented in whole or in part by software, hardware, and their combinations. The above modules can be embedded in the processor of the computer device in hardware form or be independent of it, or be stored in the memory of the computer device in software form, so that the processor can call and execute the operations corresponding to the above modules.

[0126] In one embodiment, a computer device is provided. The computer device can be a terminal, and its internal structure diagram can be as Figure 9 shown. The computer device includes a processor, a memory, a network interface, a display screen, and an input device connected through a system bus. Among them, the processor of the computer device is used to provide computing and control capabilities. The memory of the computer device includes a non-volatile storage medium and an internal memory. The non-volatile storage medium stores an operating system and a computer program. The internal memory provides an environment for the operation of the operating system and the computer program in the non-volatile storage medium. The network interface of the computer device is used to communicate with an external terminal through a network connection. When the computer program is executed by the processor, it realizes a satellite signal source optimal point calibration positioning method. The display screen of the computer device can be a liquid crystal display screen or an electronic ink display screen. The input device of the computer device can be a touch layer covering the display screen, or a button, a trackball, or a touchpad set on the shell of the computer device, or an external keyboard, a touchpad, or a mouse, etc.

[0127] Those skilled in the art can understand that Figure 9 the structure shown in

[0128] In one embodiment, a computer device is provided, including a memory and a processor. The memory stores a computer program, and when the processor executes the computer program, the steps of the method in the above embodiment are implemented.

[0129] In one embodiment, a computer-readable storage medium is provided, on which a computer program is stored. When the computer program is executed by a processor, the steps of the method in the above embodiment are implemented.

[0130] Those of ordinary skill in the art can understand that all or part of the processes in the methods of the above embodiments can be completed by instructing relevant hardware through a computer program. The computer program can be stored in a non-volatile computer-readable storage medium. When the computer program is executed, it can include the processes of the embodiments of the above methods. Among them, any reference to a memory, storage, database, or other medium used in the various embodiments provided in the present application can include non-volatile and / or volatile memories. Non-volatile memories can include read-only memory (ROM), programmable ROM (PROM), electrically programmable ROM (EPROM), electrically erasable programmable ROM (EEPROM), or flash memory. Volatile memories can include random access memory (RAM) or external cache memory. By way of illustration and not limitation, RAM is available in many forms, such as static RAM (SRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), double data rate SDRAM (DDR SDRAM), enhanced SDRAM (ESDRAM), synchronous link DRAM (SLDRAM), Rambus direct RAM (RDRAM), direct memory bus dynamic RAM (DRDRAM), and Rambus dynamic RAM (RDRAM), etc.

[0131] The technical features of the above embodiments can be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, it should be considered as the scope described in this specification.

[0132] The above-described embodiments merely represent several implementation manners of the present application. The description is relatively specific and detailed, but it should not be construed as a limitation on the scope of the invention. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present application, several modifications and improvements can still be made, and these all belong to the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the appended claims.

Claims

1. A method for correcting and positioning the optimal point of a satellite signal source, characterized in that, The method includes: Obtaining a gyro drift estimation model of a celestial gyroscope, constructing an optimization model by maximizing the denominator term of the gyro drift estimation model to minimize the gyro drift rounding error; Solving the optimization model according to the earth's angular velocity of rotation and the Schuler frequency of an inertial navigation system to obtain the maximum point of the function corresponding to the denominator term; Obtaining an initial value point set based on the maximum points within the first two earth periods of the voyage, using the Newton iteration method to solve the exact value of the initial value point close to the single-point calibration time period in the initial value point set, calculating the exact maximum point within the single-point calibration time period according to the exact value and the period of the first derivative function of the denominator term, and using the exact maximum point as the optimal gyro calibration point; Performing single-point calibration using the optimal gyro calibration point to obtain calibrated navigation and positioning data.

2. The method according to claim 1, characterized in that The solving the optimization model according to the earth's angular velocity of rotation and the Schuler frequency of an inertial navigation system to obtain the maximum point of the function corresponding to the denominator term includes: Calculating the first derivative function of the denominator term of the gyro drift estimation model with respect to time, and substituting the earth's angular velocity of rotation and the Schuler frequency of the inertial navigation system into the first derivative function; Calculating the maximum point of the function corresponding to the denominator term according to the first derivative function.

3. The method according to claim 1, wherein The using the Newton iteration method to solve the exact value of the initial value point close to the single-point calibration time period in the initial value point set includes: Obtaining a preset single-point calibration time period; Taking the initial value point close to the single-point calibration time period in the initial value point set as the initial solution, using the Newton iteration method to iteratively solve the equation when the first derivative function is 0 until the iteration stop condition is met, and outputting the exact solution.

4. The method according to claim 1, wherein The performing single-point calibration using the optimal gyro calibration point to obtain calibrated navigation and positioning data includes: Obtaining the real-time data of the celestial gyroscope at the optimal gyro calibration point, performing data validity judgment on the real-time data according to a preset data validity criterion, if the real-time data is valid, estimating the celestial gyro drift and compensating the positioning error caused thereby to obtain the output calibrated navigation and positioning data.

5. The method according to claim 4, wherein The method further includes: Performing data validity judgment on the real-time data according to a preset data validity criterion, if the real-time data is invalid, using satellite data for position resetting.

6. The method according to claim 4, wherein The validity criterion includes condition number judgment, latitude and longitude consistency check, and outlier detection.

7. The method according to claim 1, wherein The gyro drift estimation model is: Among them, is the drift of the celestial gyroscope, is the latitude change, is the latitude, is the angular velocity of the Earth's rotation, is the time, is the longitude change, is the longitude, is the Schuler frequency of the inertial navigation system.

8. A satellite signal source optimal point correction and positioning device, characterized in that, The device includes: An optimization model construction module, configured to obtain a gyro drift estimation model of a celestial gyroscope, construct an optimization model by maximizing the denominator term of the gyro drift estimation model to minimize the gyro drift rounding error; An optimization model solving module, configured to solve the optimization model according to the earth's angular velocity of rotation and the Schuler frequency of an inertial navigation system to obtain the maximum point of the function corresponding to the denominator term; The calibration point optimization module is used to obtain an initial value point set based on the maximum value points within the first two Earth cycles of the voyage, solve the exact value of the initial value point close to the single-point calibration time period in the initial value point set by using the Newton iteration method, calculate the exact maximum value point within the single-point calibration time period according to the exact value and the period of the first derivative function of the denominator term, and use the exact maximum value point as the optimal gyro calibration point; The positioning calibration module is used to perform single-point calibration by using the optimal gyro calibration point to obtain calibrated navigation positioning data.

9. A computer device, comprising a memory and a processor, the memory storing a computer program, characterized in that, When the processor executes the computer program, the steps of the method described in any one of claims 1 to 7 are implemented.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by the processor, the steps of the method described in any one of claims 1 to 7 are implemented.

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