Satellite denial-oriented intra-area navigation positioning method and system

Abstract

The invention provides a satellite denial-oriented intra-area navigation positioning method and system. The method comprises the following steps: putting and arranging a plurality of data link terminals to form a plurality of ground nodes; weaponry provided with a data chain terminal and an inertial navigation system in the air is used as an air node; calculating coordinates of the calibrated ground nodes in a geodetic coordinate system; the relative distance of the air node relative to the multiple nodes on the ground is measured through the data link terminal; an inertia / data link navigation Kalman filtering model is established, inertial navigation system errors are estimated in real time, and in the model, a plurality of relative distances serve as measurement information to construct a measurement vector Z; in the filtering process, the data link ranging validity is judged in real time, ground node fault detection is carried out, and fault nodes are removed. According to the method, the navigation positioning precision evolution in a complex environment is realized, and the high-precision positioning requirement of tactical weaponry in a satellite failure scene is met.

Description

Technical Field

[0001] The present invention belongs to the field of navigation technology, and in particular relates to a navigation positioning method and system in a satellite-denied area, mainly targeting the application fields of wartime navigation positioning and timing. Background Art

[0002] Satellite navigation systems represented by Beidou and GPS have increased the strike capability of various weapons and equipment to the meter level, transforming the original "destruction" combat mode into a modern "scalpel" fixed-point strike mode, and have been widely used. With the continuous upgrading of modern warfare confrontation means and equipment, the battlefield environment is extremely complex. Under conditions of obstruction and strong interference, it is difficult for satellite navigation systems to continuously provide stable and reliable navigation information. In regional operations, guided artillery shells, air-guided bombs, micro-UAVs and other major combat equipment are restricted by factors such as size, weight, and cost. Low-precision inertial navigation systems are used. Once the satellite signal fails, its combat performance will be greatly reduced or even unable to work. Therefore, it is urgent to carry out research on navigation and positioning methods in the region for satellite denial, as an effective supplement to satellite navigation in complex battlefield environments, to provide a time and space benchmark. Summary of the invention

[0003] The present invention aims to solve at least one of the technical problems existing in the prior art.

[0004] To this end, the present invention provides a method and system for navigation and positioning in a satellite-denied area.

[0005] The technical solution of the present invention is as follows:

[0006] According to one aspect, a method for navigation and positioning in a satellite-denied area is provided, the method comprising:

[0007] Deploy multiple data link terminals to form multiple ground nodes;

[0008] Use weapons and equipment equipped with data link terminals and inertial navigation systems in the air as air nodes;

[0009] Calculate the coordinates of the ground node marked later in the geodetic coordinate system;

[0010] The relative distance between the aerial node and multiple ground nodes is measured by the data link terminal;

[0011] Establishing an inertial / data link navigation Kalman filter model to estimate the inertial navigation system error in real time, wherein in the model, a measurement vector Z is constructed using multiple relative distances as measurement information;

[0012] During the filtering process, the validity of the data link ranging is judged in real time, ground node fault detection is performed, and faulty nodes are eliminated.

[0013] Furthermore, the method also includes: as the battlefield progresses, new ground nodes are deployed in real time, and on this basis, the dimension of the measurement vector Z is expanded in real time to update the filter model in real time.

[0014] Furthermore, the coordinates of the ground node in the geodetic coordinate system are obtained by the following formula:

[0015]

[0016] Among them, the latitude and longitude of the i-th ground node is The coordinates of the i-th ground node in the geodetic coordinate system are (x i ,y i ,z i ), R e is the radius of the earth, and N is the number of ground nodes.

[0017] Furthermore, the inertial / data link navigation Kalman filter model is established in the following way:

[0018] State vector definition

[0019] Among them, φ N ,φ U ,φ E are the north misalignment angle, celestial misalignment angle and east misalignment angle respectively; εx, εy, εz are the X gyro drift, Y gyro drift and Z gyro drift respectively; δV N ,δV U ,δV E They are the inertial navigation velocity errors in the north, sky and east directions respectively; δh, δλ are the inertial navigation latitude, altitude and longitude errors respectively;

[0020] Observation quantity definition Z = HX + V;

[0021]

[0022] The coordinates of the aerial node in the geodetic coordinate system are denoted as (x, y, z), and N equations are formed for the N sets of measured data:

[0023]

[0024] in, ρ di (i=1,2,3,…,N) is the relative distance between the ith ground node and the aerial node measured by the data link terminal, ρ ins_i is the relative distance between the i-th ground node and the aerial node solved by the inertial navigation; V is the measurement noise; H is the measurement matrix.

[0025] Furthermore, the measurement matrix is ​​obtained by the following formula:

[0026]

[0027] in, is the latitude, longitude and altitude of the aerial node;

[0028]

[0029] Furthermore, in the filtering process, the validity of data link ranging is judged in real time, ground node fault detection is performed, and faulty nodes are eliminated, which specifically includes:

[0030] Get the measurement residual r:

[0031]

[0032] in, It is the one-step prediction value of the state in the Kalman filter process;

[0033] Get the fault detection factor As shown below:

[0034]

[0035] Among them, r(i)·represents the i-th row of r;

[0036] Design threshold Δρ th ,like If the node is considered to be faulty, node i is removed, the corresponding measurement Z vector is set to 0, and the H matrix related items are set to 0; The node is considered valid and participates in the filtering calculation.

[0037] According to another aspect, a satellite-denied area navigation and positioning system is provided, and the positioning system adopts the above-mentioned positioning method to achieve satellite-denied area navigation and positioning.

[0038] The above technical solution aims at the problem of reduced navigation accuracy of weapons and equipment under satellite denial. It uses data link and inertial navigation system to build PNT network, combines trajectory constraints for filtering estimation, corrects inertial error in real time, and improves navigation accuracy. Specifically, this method combines the advantages of inertial full autonomy and high-precision ranging of data link to realize the real-time evolution of navigation positioning and accuracy of regional PNT network: first, through weapons and equipment such as drones and guided munitions, multiple data link terminals are deployed as ground nodes, and the coordinates of the later ground nodes in the geodetic coordinate system are calculated. Weapons and equipment equipped with data link terminals and inertial navigation systems in the air are used as aerial nodes. The relative distance of the aerial nodes relative to multiple ground nodes is measured by the data link terminals. Then, a Kalman filter model is established, and this is used as measurement information to estimate the inertial navigation system error in real time, and then closed-loop correction is made to improve navigation accuracy. As the battlefield advances, more ground nodes are deployed in real time. At the same time, node fault detection is performed, faulty nodes are proposed, new step nodes are added, and the filter model is updated in real time to improve the reliability of the entire network system and realize self-evolution of accuracy. In the case of satellite denial, high-precision and high-reliability navigation information is provided for weapons and equipment. DETAILED DESCRIPTION

[0039] It should be noted that, in the absence of conflict, the embodiments in this application and the features in the embodiments can be combined with each other. The technical solutions in the embodiments of the present invention are clearly and completely described below. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all of the embodiments. The following description of at least one exemplary embodiment is actually only illustrative and is by no means intended to limit the present invention and its application or use. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0040] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof.

[0041] Unless otherwise specifically stated, the relative arrangement of the parts and steps set forth in these embodiments, numerical expressions and numerical values ​​do not limit the scope of the present invention. The technology, method and equipment known to those of ordinary skill in the relevant art may not be discussed in detail, but in appropriate cases, the technology, method and equipment should be considered as a part of the authorization specification. In all examples shown and discussed here, any specific value should be interpreted as being merely exemplary, rather than as a limitation. Therefore, other examples of exemplary embodiments may have different values.

[0042] In one embodiment of the present invention, a method for navigation and positioning in a satellite-denied area is provided, the method comprising:

[0043] Step 1: deploy multiple data link terminals to form multiple ground nodes;

[0044] Step 2: Use weapons and equipment equipped with data link terminals and inertial navigation systems in the air as air nodes;

[0045] Step 3: Calculate the coordinates of the ground node marked later in the geodetic coordinate system;

[0046] Step 4: Measure the relative distance between the aerial node and multiple ground nodes through the data link terminal;

[0047] Step 5: Establish an inertial / data link navigation Kalman filter model to estimate the inertial navigation system error in real time, wherein in the model, a measurement vector Z is constructed using multiple relative distances as measurement information;

[0048] Step 6: During the filtering process, the validity of the data link ranging is judged in real time, ground node fault detection is performed, and faulty nodes are eliminated.

[0049] That is, in order to meet the needs of high-precision and high-reliability positioning of weapons and equipment, this embodiment proposes a navigation and positioning method for satellite-denied areas, which mainly deploys ground nodes in real time, adopts an inertial / data link combination, and corrects inertial errors in real time. As the battlefield advances, faulty nodes are eliminated and the number of ground nodes is increased in real time to achieve the evolution of navigation and positioning accuracy in complex environments, thereby making up for the high-precision positioning needs of tactical weapons and equipment in satellite failure scenarios.

[0050] The embodiment of the present invention can first deploy multiple data link terminals as ground nodes through weapons and equipment such as drones and guided munitions, and calculate the coordinates of the later ground nodes in the geodetic coordinate system. Weapons and equipment equipped with data link terminals and inertial navigation systems in the air are used as aerial nodes, and the relative distances of the aerial nodes relative to multiple ground nodes are measured by the data link terminals. A Kalman filter model is then established, and this is used as measurement information to estimate the inertial navigation system error in real time, and then closed-loop correction is performed to improve navigation accuracy. As the battlefield advances, more ground nodes are deployed in real time, and at the same time, node fault detection is performed to eliminate faulty nodes.

[0051] In an embodiment of the present invention, the existing method can be used to obtain the coordinates of the calibrated ground node, and the ground node can also be calibrated through the aerial node. The specific method is: obtain the real-time position information of the aerial node through the inertial navigation system; use the data link to measure the distance information between the ground node and the aerial node in real time; based on the distance information, use the Newton iteration method based on least squares to estimate the position of the ground node and the time transmission error, that is, to obtain the position information of the ground node.

[0052] Specifically, in step 3, the latitude, longitude and altitude of the i-th ground node are obtained by using the regional PNT ground node comparison method. Calculate its coordinates in the geodetic coordinate system (x i ,y i ,z i ):

[0053]

[0054] in, N is the number of ground nodes.

[0055] In the embodiment of the present invention, an inertial / data link navigation Kalman filter model is established, which is as follows:

[0056] State vector definition Observation quantity definition Z=HX+V:

[0057]

[0058] Among them, φ N ,φ U ,φ E , respectively: north misalignment angle, celestial misalignment angle, east misalignment angle; εx, εy, εz are X gyro drift, Y gyro drift, Z gyro drift; δV N ,δV U ,δV E , are the inertial navigation velocity errors in the north, sky and east directions respectively; δh,δλ are the inertial navigation latitude, altitude and longitude errors respectively.

[0059] The coordinates of the aerial flight node in the geodetic coordinate system are recorded as (x, y, z), and N equations are formed for the N sets of measured data:

[0060]

[0061] in,

[0062] ρ di (i=1,2,3,…,N) is the relative distance between the ith ground node and the aerial node, measured by the data link deployed on the ground node.

[0063] The coordinate transformation relationships of aerial nodes are:

[0064]

[0065] in are the latitude, longitude and altitude of the aerial node; (x, y, z) are the coordinates of the aerial node in the geodetic coordinate system.

[0066] remember The error equivalent to the e-system is [δx e ,δy e ,δz e ], ignoring the effect of latitude error on R N The influence of , the first-order Taylor expansion of equation (4) is obtained as follows:

[0067]

[0068] Similarly, the first-order Taylor expansion of the observed quantity Z is obtained:

[0069]

[0070] make:

[0071]

[0072] have:

[0073]

[0074] in,

[0075]

[0076] Thus, a filtering model is obtained, and real-time filtering is performed based on the above filtering model to estimate the inertia error and then perform closed-loop correction.

[0077] In the above embodiment, the filtering process determines the validity of data link ranging in real time, performs ground node fault detection, and removes faulty nodes, specifically including:

[0078] Get the measurement residual r:

[0079]

[0080] in, It is the one-step prediction value of the state in the Kalman filter process;

[0081] Get the fault detection factor As shown below:

[0082]

[0083] Among them, r(i)·represents the i-th row of r;

[0084] Design threshold Δρ th ,like If the node is considered to be faulty, node i is removed, the corresponding measurement Z vector is set to 0, and the H matrix related items are set to 0; The node is considered valid and participates in the filtering calculation.

[0085] In the above embodiment, the method further includes: as the battlefield progresses, new ground nodes are deployed in real time, and on this basis, the dimension of the measurement vector Z is expanded in real time to update the filter model in real time.

[0086] That is, as the battlefield advances, new ground nodes can be deployed in real time through weapons and equipment such as drones and guided ammunition, and the ground nodes can be marked in real time through aerial nodes to obtain the location information of the new ground nodes. The above steps can be repeated, and the dimension of the Z measurement vector can be expanded in real time. The filter model can be updated in real time through step 5 to improve the measurement dimension, thereby achieving the purpose of self-evolution of accuracy and improving the fault tolerance and reliability of the system.

[0087] It can be seen that the embodiment of the present invention aims at the problem of reduced navigation accuracy of weapons and equipment under satellite denial, uses data link and inertial navigation system to build PNT network, combines trajectory constraints to perform filtering estimation, corrects inertial error in real time, and improves navigation accuracy. Specifically, the method combines the advantages of inertial full autonomy and high-precision ranging of data link to achieve navigation positioning and real-time evolution of accuracy of regional PNT network: first, through weapons and equipment such as unmanned aerial vehicles and guided munitions, multiple data link terminals are deployed as ground nodes, and the coordinates of the ground nodes with the later marks in the geodetic coordinate system are calculated. Weapons and equipment equipped with data link terminals and inertial navigation systems in the air are used as aerial nodes, and the relative distances of the aerial nodes relative to multiple ground nodes are measured by the data link terminals. Then a Kalman filter model is established, and this is used as measurement information to estimate the inertial navigation system error in real time, and then closed-loop correction is performed to improve navigation accuracy. As the battlefield advances, more ground nodes are deployed in real time, and at the same time, node fault detection is performed, faulty nodes are proposed, new step nodes are added, and the filter model is updated in real time to improve the reliability of the entire network system and achieve self-evolution of accuracy. In the case of satellite denial, high-precision and high-reliability navigation information is provided for weapons and equipment.

[0088] According to another embodiment, a navigation and positioning system for a satellite-denied area is provided. The positioning system adopts the positioning method of the above embodiment to implement navigation and positioning for a satellite-denied area.

[0089] That is, the implementation principle of the system is consistent with the method of the above-mentioned embodiment, and will not be elaborated here.

[0090] Features described and / or illustrated above for one embodiment may be used in the same or similar manner in one or more other embodiments, and / or combined with or used in place of features in other embodiments.

[0091] It should be emphasized that the term "include / comprises" when used herein refers to the presence of features, integers, steps or components, but does not exclude the presence or addition of one or more other features, integers, steps, components or combinations thereof.

[0092] The above method of the present invention can be implemented by hardware, or by hardware combined with software. The present invention relates to such a computer-readable program, which, when executed by a logic component, enables the logic component to implement the above-mentioned device or component, or enables the logic component to implement the above-mentioned various methods or steps. The present invention also relates to a storage medium for storing the above program, such as a hard disk, a magnetic disk, an optical disk, a DVD, a flash memory, etc.

[0093] The many features and advantages of these embodiments are apparent from this detailed description, and thus the appended claims are intended to cover all such features and advantages of these embodiments that fall within their true spirit and scope. Furthermore, since numerous modifications and changes will readily occur to those skilled in the art, it is not intended that the embodiments of the invention be limited to the exact construction and operation illustrated and described, but rather all suitable modifications and equivalents falling within the scope thereof are intended to be covered.

[0094] Parts of the present invention that are not described in detail are well known to those skilled in the art.

Claims

1. A method for navigation and positioning in a satellite-denied area, characterized in that: The positioning method comprises: Deploy multiple data link terminals to form multiple ground nodes; Use weapons and equipment equipped with data link terminals and inertial navigation systems in the air as air nodes; Calculate the coordinates of the ground node marked later in the geodetic coordinate system; The relative distance between the aerial node and multiple ground nodes is measured by the data link terminal; Establishing an inertial / data link navigation Kalman filter model to estimate the inertial navigation system error in real time, wherein in the model, a measurement vector Z is constructed using multiple relative distances as measurement information; During the filtering process, the validity of the data link ranging is judged in real time, ground node fault detection is performed, and faulty nodes are eliminated.

2. The method for navigation and positioning in a satellite-denied area according to claim 1, characterized in that: The method also includes: as the battlefield advances, new ground nodes are deployed in real time, and on this basis, the dimension of the measurement vector Z is expanded in real time to update the filter model in real time.

3. A method for navigation and positioning in a satellite-denied area according to claim 1 or 2, characterized in that: The coordinates of the ground node in the geodetic coordinate system are obtained by the following formula: Among them, the latitude and longitude of the i-th ground node is The coordinates of the i-th ground node in the geodetic coordinate system are (x i ,y i ,z i ), R e is the radius of the earth, and N is the number of ground nodes.

4. A method for navigation and positioning in a satellite-denied area according to any one of claims 1 to 3, characterized in that: The inertial / data link navigation Kalman filter model is established in the following way: State vector definition Among them, φ N ,φ U ,φ E are the north misalignment angle, celestial misalignment angle and east misalignment angle respectively; εx, εy, εz are the X gyro drift, Y gyro drift and Z gyro drift respectively; δV N ,δV U ,δV E They are the inertial navigation velocity errors in the north, sky and east directions respectively; are the inertial navigation latitude, altitude and longitude errors respectively; Observation quantity definition Z = HX + V; The coordinates of the aerial node in the geodetic coordinate system are denoted as (x, y, z), and N equations are formed for the N sets of measured data: in, ρ di (i=1,2,3,…,N) is the relative distance between the ith ground node and the aerial node measured by the data link terminal, ρ ins_i is the relative distance between the i-th ground node and the aerial node solved by the inertial navigation; V is the measurement noise; H is the measurement matrix.

5. The method for navigation and positioning in a satellite-denied area according to claim 4, characterized in that: The measurement matrix is ​​obtained by the following formula: in, is the latitude, longitude and altitude of the aerial node; 6. The method for navigation and positioning in a satellite-denied area according to claim 5, characterized in that: In the filtering process, the validity of data link ranging is judged in real time, ground node fault detection is performed, and faulty nodes are eliminated, which specifically includes: Get the measurement residual r: in, It is the one-step prediction value of the state in the Kalman filter process; Get the fault detection factor As shown below: Among them, r(i)·represents the i-th row of r; Design threshold Δρ th ,like If the node is considered to be faulty, node i is removed, the corresponding measurement Z vector is set to 0, and the H matrix related items are set to 0; The node is considered valid and participates in the filtering calculation.

7. A navigation and positioning system for satellite-denied areas, characterized in that: The positioning system adopts the positioning method described in any one of claims 1 to 6 to achieve navigation positioning in a satellite-denied area.

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