阅读说明：本技术 一种重力辅助惯性导航系统仿真平台 (Gravity-assisted inertial navigation system simulation platform ) 是由 邓志红 石雷 赵生武 王博 王宇 张文喆 于 2021-05-19 设计创作，主要内容包括：本发明公开了一种重力辅助惯性导航系统仿真平台。本发明仿真平台包括重力场背景图模块、适配区选取模块、航迹规划模块、惯性导航模块、重力匹配模块、修正模块、界面显示模块和接口定义文档；本发明定义各程序之间接口,只要将数据调整成接口格式,即可使用整个平台进行仿真或半实物仿真,保证仿真数据、实际测试数据的有效衔接。仿真平台各个模块可以串联顺序使用,也可以单独使用,根据输入输出及接口格式编写所需测试的新算法,加入相应模块中进行测试,方便各部分进行理论和方法的验证,减少了实际试验的时间和成本。此外,本发明能够仿真多种误差因素,使仿真评估结果更逼近真实结果,提高了重力辅助惯性导航系统研究的有效性。(The invention discloses a gravity-assisted inertial navigation system simulation platform. The simulation platform comprises a gravity field background image module, an adaptation area selection module, a track planning module, an inertial navigation module, a gravity matching module, a correction module, an interface display module and an interface definition document; the invention defines the interfaces among all programs, and can use the whole platform to carry out simulation or semi-physical simulation as long as the data is adjusted into the interface format, thereby ensuring the effective connection of simulation data and actual test data. The simulation platform can be used in series and in sequence or independently, a new algorithm required to be tested is compiled according to input, output and interface formats, and the new algorithm is added into the corresponding module for testing, so that the verification of theories and methods of all parts is facilitated, and the time and cost of actual tests are reduced. In addition, the method can simulate various error factors, so that the simulation evaluation result is closer to the real result, and the research effectiveness of the gravity-assisted inertial navigation system is improved.)

1. A gravity assisted inertial navigation system simulation platform, comprising: the system comprises a gravity field background image module, an adaptation area selection module, a track planning module, an inertial navigation module, a gravity matching module, a correction module, an interface display module and an interface definition document;

the gravity field background image module carries out interpolation reconstruction on the gravity field background image of the current area according to the gravity anomaly measurement value;

the adaptation area selection module divides the gravity field background image into areas according to the change degree of the gravity abnormal value in the gravity field background image, and selects an adaptation area suitable for navigation of the underwater carrier;

the flight path planning module plans the flight path of the underwater carrier, so that the flight path of the underwater carrier passes through all the adaptive areas; meanwhile, in each adaptation area, the flight path passes through a point with severe change of the gravity abnormal value in the adaptation area;

the inertial navigation module generates inertial navigation system data of the underwater carrier according to the planned track, and performs positioning calculation;

the gravity matching module matches the positioning result output by the inertial navigation module with the gravity field background image output by the gravity field background image module to determine a gravity matching point;

the correction module corrects the positioning result of the inertial navigation system according to the gravity matching point and outputs the corrected position;

the interface display module is used for displaying the output result of each module;

the interface definition document is used for defining and unifying the input and output formats of the modules.

2. The gravity-assisted inertial navigation system simulation platform of claim 1, wherein the gravity matching module comprises a matching range sub-module and a correlation computation sub-module;

the matching range submodule draws an isoline zone range according to the gravity measurement data, draws a circle probability radius range according to the positioning position of the inertial navigation module, and the intersection of the isoline zone range and the circle probability radius range is a matching range; grid intersection points in the gravity background image in the matching range are candidate matching points;

the correlation calculation submodule performs correlation calculation on the gravity value of the candidate matching point on one hand, and performs track shape correlation calculation on the candidate matching point by using the track of the positioning result of the inertial navigation system on the other hand; and determining a final gravity value matching point according to the gravity value correlation calculation result and the track shape correlation calculation result.

3. The gravity-assisted inertial navigation system simulation platform of claim 2, wherein in the trajectory shape correlation calculation, the slope of the trajectory of the inertial navigation system positioning result is used as a trajectory shape template to perform the trajectory shape correlation calculation.

4. The gravity assisted inertial navigation system simulation platform of claim 2 or 3, wherein in performing the correlation calculations, a fast Fourier transform is performed on the correlation calculations.

5. The gravity-assisted inertial navigation system simulation platform of claim 1, wherein the gravity matching module further comprises a mismatch detection sub-module, and the mismatch detection sub-module performs a triangle similarity determination on a triangle formed by 3 consecutive positioning results of the inertial navigation system and a triangle formed by corresponding positions of 3 consecutive gravity value matching points; if the two triangles are judged to be similar, the current gravity value matching point is considered to be feasible; otherwise, the current gravity value matching point is considered as a mismatching point, the mismatching point is removed, and a virtual matching point is constructed by the similarity of the triangles to carry out the next mismatching detection.

Technical Field

The invention relates to the technical field of navigation, guidance and control, in particular to a gravity-assisted inertial navigation system simulation platform.

Background

The inertial navigation system can provide navigation positioning information such as position, speed, attitude and the like for the carrier in real time, and is widely applied to various carriers such as land, sea, air and sky. For long-term navigation time carriers such as an underwater vehicle, the error of the inertial navigation system is dispersed along with time, and the navigation requirement cannot be met. The marine gravity measurement is passivity and stable in gravity information, and the gravity-assisted inertial navigation becomes a research hotspot of underwater autonomous navigation. With the research on the gravity-assisted inertial navigation system, a great deal of research and test work is required. The practical test has the problems of long period, high cost, incapability of separating various error sources to carry out single-item test and the like. To solve this problem, designing a simulation platform based on gravity assistance is an effective approach. The existing research on gravity-assisted inertial navigation is to research an inertial navigation system and a gravity-assisted system respectively, however, the main purpose of the gravity-assisted system is to correct inertial navigation errors, and the two are not effectively combined together at present. In addition, interfaces among all program modules cannot be matched, systematicness is lacked, simulation conditions are ideal, and unified evaluation standards are not provided, so that efficiency is low.

Disclosure of Invention

In view of this, the invention provides a gravity-assisted inertial navigation system simulation platform, which can effectively combine an inertial navigation system with a gravity-assisted system, overcome the problems that interfaces among program modules in the prior art cannot be matched and the systematicness is poor, reduce time and cost consumed in research and test, and improve the research efficiency of the gravity-assisted inertial navigation system.

The invention discloses a gravity-assisted inertial navigation system simulation platform, which comprises: the system comprises a gravity field background image module, an adaptation area selection module, a track planning module, an inertial navigation module, a gravity matching module, a correction module, an interface display module and an interface definition document;

the gravity field background image module carries out interpolation reconstruction on the gravity field background image of the current area according to the gravity anomaly measurement value;

the adaptation area selection module divides the gravity field background image into areas according to the change degree of the gravity abnormal value in the gravity field background image, and selects an adaptation area suitable for navigation of the underwater carrier;

the flight path planning module plans the flight path of the underwater carrier, so that the flight path of the underwater carrier passes through all the adaptive areas; meanwhile, in each adaptation area, the flight path passes through a point with severe change of the gravity abnormal value in the adaptation area;

the inertial navigation module generates inertial navigation system data of the underwater carrier according to the planned track, and performs positioning calculation;

the gravity matching module matches the positioning result output by the inertial navigation module with the gravity field background image output by the gravity field background image module to determine a gravity matching point;

the correction module corrects the positioning result of the inertial navigation system according to the gravity matching point and outputs the corrected position;

the interface display module is used for displaying the output result of each module;

the interface definition document is used for defining and unifying the input and output formats of the modules.

Preferably, the gravity matching module comprises a matching range sub-module and a related calculation sub-module;

the matching range submodule draws an isoline zone range according to the gravity measurement data, draws a circle probability radius range according to the positioning position of the inertial navigation module, and the intersection of the isoline zone range and the circle probability radius range is a matching range; grid intersection points in the gravity background image in the matching range are candidate matching points;

the correlation calculation submodule performs correlation calculation on the gravity value of the candidate matching point on one hand, and performs track shape correlation calculation on the candidate matching point by using the track of the positioning result of the inertial navigation system on the other hand; and determining a final gravity value matching point according to the gravity value correlation calculation result and the track shape correlation calculation result.

Preferably, during the track shape correlation calculation, the slope of the track of the positioning result of the inertial navigation system is used as a track shape template to perform the track shape correlation calculation.

Preferably, when performing the correlation calculation, a fast fourier transform is performed on the correlation calculation.

Preferably, the gravity matching module further comprises a mismatching detection submodule, and the mismatching detection submodule is used for judging the similarity of a triangle formed by 3 continuous positioning results of the inertial navigation system and a triangle formed by the positions of corresponding 3 continuous gravity value matching points; if the two triangles are judged to be similar, the current gravity value matching point is considered to be feasible; otherwise, the current gravity value matching point is considered as a mismatching point, the mismatching point is removed, and a virtual matching point is constructed by the similarity of the triangles to carry out the next mismatching detection.

Has the advantages that:

(1) the invention effectively combines the inertial navigation system and the gravity auxiliary system, and solves the problems that the interfaces among the program modules can not be matched and the systematicness is poor in the prior art; the invention defines the interfaces among all programs, and can use the whole platform to carry out simulation or semi-physical simulation as long as the data is adjusted into the interface format, thereby ensuring the effective connection of simulation data and actual test data. The simulation platform can be used in series and in sequence or independently, a new algorithm required to be tested is compiled according to input, output and interface formats, and the new algorithm is added into the corresponding module for testing, so that the verification of theories and methods of all parts is facilitated, and the time and cost of actual tests are reduced. In addition, the method can simulate various error factors, so that the simulation evaluation result is closer to the real result, and the research effectiveness of the gravity-assisted inertial navigation system is improved.

(2) The gravity assisted matching module firstly comprehensively considers the characteristics of gravity error and inertial navigation error, and determines the matching range through the gravity error and the inertial navigation error, so that the searching range is more accurate; and secondly, when the gravity is matched, the correlation of the inertial navigation resolving track and a track formed by the positions of the candidate matching points is used as one of evaluation criteria for matching while the gravity value correlation filtering is utilized, so that the matching accuracy is improved.

(3) According to the method, the fast Fourier transform is used in the gravity value correlation calculation and the track shape correlation calculation, so that the operation speed is increased, and the time consumption of a matching algorithm is reduced.

(4) Through the mismatching submodule, the abnormal matching points can be detected, and can be estimated according to the geometric relationship, so that the influence of the mismatching points is reduced.

Drawings

FIG. 1 is a diagram of a simulation platform of a gravity-assisted inertial navigation system according to the present invention.

FIG. 2 is a flow chart of simulation of the simulation platform of the present invention.

Detailed Description

The invention is described in detail below by way of example with reference to the accompanying drawings.

The invention provides a gravity-assisted inertial navigation system simulation platform, which is used for testing a gravity-assisted inertial navigation system; the simulation platform structure is schematically shown in fig. 1, and includes: the system comprises a gravity field background image module, an adaptation area selection module, a track planning module, an inertial navigation module, a gravity matching module, a correction module, an interface display module and an interface definition document;

wherein, (1) the gravity field background image module

The points collected by the gravity sensor are discontinuous, and the resolution is low. And the gravity field background image module carries out interpolation reconstruction on the gravity field background image according to the gravity abnormal observed quantity. The interpolation has the function of constructing a high-resolution gravity field background image, improving the precision and establishing a foundation for the high-precision positioning of the gravity-assisted inertial navigation system. The accurate gravity field background image can eliminate partial gravity disturbance errors. The input of the gravity field background image module is the latitude and longitude range, the resolution and the adopted interpolation method of the required area, and the output is the gravity field background image.

(2) Adaptive area selection module

After the gravity field background image is constructed, the gravity field background image needs to be analyzed, and an adaptation area is divided. The adaptation area refers to an area suitable for navigation of the underwater carrier, the gravity abnormal value change degree of the area is severe, matching is carried out in the adaptation area, and the accuracy is obviously higher than that of other areas. Different adaptation zones can be divided by analyzing different angles of the gravity field background image. The module inputs a gravity field background image, outputs an adaptation value file corresponding to the gravity field background image through an adaptation area selection method, and obtains an adaptation area through threshold setting.

(3) Flight path planning module

The planning of the flight path is divided into 2 aspects: adaptation interval and adaptation zone. And calculating all the adaptation areas which need to pass from the starting point to the end point by the flight path planning of the adaptation areas. In each adaptation area, the flight path planning is required according to the change degree of the gravity abnormal value, so that the planned flight path passes through the point with severe change of the gravity abnormal value in the adaptation area. The underwater carrier can be guided to pass through the adaptation area through a flight path planning algorithm, so that the matching positioning precision is improved. The module inputs a gravity field background picture and a corresponding adaptive value file, and outputs a track after track planning through a track planning algorithm at the starting point and the end point of the carrier.

(4) Inertial navigation module

The inertial navigation comprises two parts of inertial data generation and inertial navigation resolving. The data generation part can set sensor errors such as inertial devices, DVL and the like, and can generate data of a strapdown inertial navigation system or data of a gyroscope accelerometer of a biaxial rotation modulation inertial navigation system according to a manually designed track or a track planning track. The inertial navigation resolving part inputs the inertial data to generate partial data and outputs the inertial navigation resolving result.

(5) Gravity matching module

The gravity matching algorithm is a core technology of gravity-assisted inertial navigation. The matching algorithm determines the optimal matching sequence or matching point by comprehensively analyzing inertial navigation information, real-time gravity measurement information and information provided by a gravity field background image, thereby obtaining the estimation of the carrier position information. The module inputs a gravity field background picture, calculates a result through inertial navigation and outputs a matching result estimated through a matching algorithm.

Specifically, in this embodiment, the gravity matching module includes a matching range sub-module and a correlation calculation sub-module;

the matching range submodule draws an isoline zone range according to the gravity measurement data, draws a circle probability radius range according to the positioning position of the inertial navigation module, and the intersection of the isoline zone range and the circle probability radius range is a matching range; grid intersection points in the gravity background image in the matching range are candidate matching points;

during correlation calculation, if a correlation value obtained by matching the gravity value of the candidate matching point position with the gravity value correlation calculation template is directly used as a judgment criterion, the phenomenon that the gravity values are the same but the positions are wrong easily occurs, because the gravity value correlation calculation template only has the gravity value, and the relative relationship of the positions of all points is not considered. Therefore, the embodiment also matches the correlation between the inertial navigation system resolving track and the track formed by the positions of the candidate matching points as one of the evaluation criteria. When the inertial navigation track is considered, only whether the shapes are similar or not needs to be considered, so that the slope between each point of the inertial navigation track can be taken as a sequence, which is called a track shape template. And matching the position of the candidate matching point with the track shape template to obtain the track shape correlation.

Therefore, the correlation calculation submodule performs correlation calculation on the gravity value of the candidate matching point on one hand, and performs track shape correlation calculation on the candidate matching point by using the track of the positioning result of the inertial navigation system on the other hand; and determining a final gravity value matching point according to the gravity value correlation calculation result and the track shape correlation calculation result. In addition, considering that the calculation amount of the correlation calculation is large and takes long time, the fast fourier transform is performed on the correlation calculation in the embodiment, so that the convolution becomes dot multiplication, and the calculation amount can be greatly reduced.

In addition, in this embodiment, the gravity matching module further includes a mismatch detection sub-module, which prevents an excessive error of the matching position. The mismatching detection submodule carries out triangle similarity judgment on a triangle formed by 3 continuous positioning results of the inertial navigation system and a triangle formed by the positions of corresponding 3 continuous gravity value matching points; if the two triangles are judged to be similar, the current gravity value matching point is considered to be feasible; otherwise, the current gravity value matching point is considered as a mismatching point, the mismatching point is removed, and a virtual matching point is constructed by the similarity of the triangles to carry out the next mismatching detection.

Specific matching algorithms can be found in the related filtering-based gravity matching method of the same-day application.

(6) Correction module

The correction module is connected with the inertial navigation module and the gravity matching module, and realizes correction of errors of the inertial navigation system through a combined navigation or comprehensive correction technology, so that the navigation precision is improved. The input of the part is an inertial navigation resolving result and a gravity matching result, the inertial navigation is corrected through a correction algorithm, and the corrected position is output.

(7) Interface display module

MATLB is adopted as software for building an interface display module, and GUI is used for completing all functions. All functions of the invention can find corresponding parts in the interface display module and display the results of all parts. The interface display module has the main function of displaying non-technical personnel, so that a user can complete the bidirectional interaction function without knowing specific algorithm steps.

(8) Interface definition document

Various algorithms exist in each module, and the result formats of the algorithms are different. By defining an interface, the input and output of each algorithm in the gravity field background image module, the adaptive area selection module, the track planning module, the inertial navigation module, the gravity matching module and the correction module have a uniform format, so that the connection among all parts of the simulation platform is realized, and the independent test function of each module is realized.

The simulation platform of the invention comprises the following specific use steps:

step 1, carefully reading interface definition documents and knowing input and output of each module and interface formats;

and 2, generating required data according to the input and output requirements of each module.

The simulation platform of the invention can use all modules in series and in sequence, can also use independently, compile a new algorithm to be tested according to input, output and interface formats, and add the new algorithm into the corresponding module for testing.

Because each module defines a standard data format conversion program, the effective connection of simulation data and actual test data can be ensured.

In addition, the simulation platform can run the existing program to be compared with the new algorithm and can also run the interface display module to show the program to others.

In summary, the above description is only a preferred embodiment of the present invention, and is not intended to limit the scope of the present invention. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.