CN117008044B

CN117008044B - Pure-azimuth passive positioning method and system for unmanned aerial vehicle

Info

Publication number: CN117008044B
Application number: CN202311275557.1A
Authority: CN
Inventors: 徐标; 郭宏彬; 付梓凡; 谢晶婷; 穰歌捷; 李恪; 范衠
Original assignee: Shantou University
Current assignee: Shantou University
Priority date: 2023-09-28
Filing date: 2023-09-28
Publication date: 2023-12-12
Anticipated expiration: 2043-09-28
Also published as: CN117008044A

Abstract

The invention is applied to the technical field of unmanned aerial vehicle positioning, and discloses a pure-azimuth passive positioning method and a pure-azimuth passive positioning system for an unmanned aerial vehicle, wherein the method comprises the steps of acquiring a circle center unmanned aerial vehicle when an unmanned aerial vehicle cluster flies, constructing a circular flight orbit based on the circle center unmanned aerial vehicle, and determining a transmitter unit and a plurality of receivers to be positioned which belong to the orbit; determining the number information of the transmitter unit, and determining the positions of a plurality of receivers to be positioned with the current position of the transmitter unit, so that each receiver to be positioned is positioned on a track; and judging whether the clusters have other unmanned aerial vehicles which are not positioned, if so, returning to the step of constructing the track by taking each receiver to be positioned as the circle center unmanned aerial vehicle until all unmanned aerial vehicles in the clusters are positioned on the corresponding tracks, and constructing the radial flight formation of the clusters. The invention reduces the dependence on external sensors and GPS technology, improves the positioning precision of the unmanned aerial vehicle, reduces the calculation complexity of unmanned aerial vehicle positioning and adjusting formation, improves the positioning efficiency of the unmanned aerial vehicle, and meets the requirement of real-time positioning.

Description

Pure-azimuth passive positioning method and system for unmanned aerial vehicle

Technical Field

The invention relates to the technical field of unmanned aerial vehicle positioning, in particular to a pure-azimuth passive positioning method and system for an unmanned aerial vehicle.

Background

The background of existing unmanned aerial vehicle positioning technology is derived from the continuous expansion and intensive research of unmanned aerial vehicle applications. The unmanned aerial vehicle is used as an aircraft without personnel control, and has wide application prospect. The positioning technology plays an important role in unmanned aerial vehicle navigation, flight path planning and the like, has critical significance for unmanned aerial vehicle path planning, fixed point delivery, data acquisition and other tasks, and can improve the working accuracy and autonomy of the unmanned aerial vehicle. Related positioning technologies of unmanned aerial vehicles generally include GPS (Global Positioning System ) positioning technology, inertial navigation technology, and visual positioning technology, which have the following drawbacks:

although GPS positioning technology has many advantages, in a specific environment such as a high-rise area, an indoor location, or a deep valley, GPS signals may be negatively affected by building shielding or interference, resulting in a decrease in positioning accuracy of the unmanned aerial vehicle. The positioning accuracy of the inertial navigation technology is easily limited by the cost of the device, and the inertial navigation device can generate accumulated errors along with the time, so that the positioning accuracy of the unmanned aerial vehicle is affected. In order to keep higher positioning accuracy, the inertial navigation technology needs to calibrate the position estimation by means of an external positioning information source continuously, so that the calibration time occupies most of the positioning time of the unmanned aerial vehicle, and the positioning efficiency of the unmanned aerial vehicle is reduced. In addition, the visual positioning technology generally needs strong computing power and complex image processing algorithm, and particularly in fast moving and complex scenes, the challenges of computing complexity and real-time performance may affect the positioning accuracy and practicality of the unmanned aerial vehicle, which not only can lead to the reduction of the positioning accuracy of the unmanned aerial vehicle, but also can lead to the longer positioning time of the unmanned aerial vehicle due to high computing complexity, and cannot realize the effect of real-time positioning.

The above problems are to be solved.

Disclosure of Invention

The application aims to provide a pure-azimuth passive positioning method and system for an unmanned aerial vehicle, which are used for solving one or more technical problems in the prior art and at least providing a beneficial selection or creation condition.

The application solves the technical problems as follows: in a first aspect, the application provides a purely azimuthal passive positioning method for an unmanned aerial vehicle, comprising the following steps:

when the unmanned aerial vehicle clusters fly, acquiring a circle center unmanned aerial vehicle, constructing a circular flight orbit based on the circle center unmanned aerial vehicle, and determining a transmitter unit belonging to the circular flight orbit and a plurality of receivers with unknown positions to be positioned;

the system comprises a transmitter set, a first unmanned aerial vehicle and a plurality of transmitters, wherein the current position and the number information of the center unmanned aerial vehicle are known, the center unmanned aerial vehicle is located at the center of a circular flight orbit, the first unmanned aerial vehicle is close to the circular flight orbit, and the distance between the circular flight orbit and the first unmanned aerial vehicle is smaller than the distance between the circular flight orbit and any transmitter;

determining the number information of the transmitter unit, and positioning the positions of a plurality of receivers to be positioned according to the number information and the current position of the transmitter unit;

When each receiver to be positioned completes position positioning, each receiver to be positioned is positioned on a circular flight orbit, and whether the rest unmanned aerial vehicles which are not positioned exist in the unmanned aerial vehicle cluster is judged;

when the unmanned aerial vehicle clusters are provided with other unmanned aerial vehicles which are not positioned, each receiver to be positioned is used as a circle center unmanned aerial vehicle, the step of building a circular flight orbit based on the circle center unmanned aerial vehicle is returned until all unmanned aerial vehicles in the unmanned aerial vehicle clusters are positioned on the corresponding circular flight orbits, and then the radial flight formation of the unmanned aerial vehicle clusters is built.

In a second aspect, the present application provides a purely azimuthal passive positioning system for an unmanned aerial vehicle, comprising:

the data processing module is used for acquiring the circle center unmanned aerial vehicle and constructing a circular flight orbit based on the circle center unmanned aerial vehicle when the unmanned aerial vehicle cluster flies, and determining a transmitter unit belonging to the circular flight orbit and a plurality of receivers with unknown positions to be positioned;

The numbering prediction module is used for determining the numbering information of the transmitter group;

the positioning adjustment module is used for positioning the positions of the plurality of receivers to be positioned according to the number information and the current position of the transmitter unit, and when each receiver to be positioned finishes position positioning, each receiver to be positioned is positioned on the circular flight orbit;

the judgment control module is used for judging whether other unmanned aerial vehicles which are not positioned exist in the unmanned aerial vehicle cluster, when the unmanned aerial vehicles which are not positioned exist in the unmanned aerial vehicle cluster, each receiver to be positioned is used as a circle center unmanned aerial vehicle, the circle center-based unmanned aerial vehicle is returned to construct a circular flight orbit until all unmanned aerial vehicles in the unmanned aerial vehicle cluster are positioned on the corresponding circular flight orbit, and then the radial flight formation of the unmanned aerial vehicle cluster is constructed.

The beneficial effects of the invention are as follows: the method comprises the steps of firstly, carrying out numbering prediction on a sender without numbering information by using a DBSCAN algorithm, and according to the numbering information and the current position of the sender set, combining a geometric positioning algorithm and a greedy algorithm to realize the position positioning and adjustment of a plurality of receivers to be positioned; and (3) the positions of the receivers to be positioned of the plurality of circular flight tracks are adjusted to construct a standard unmanned aerial vehicle cluster radial flight formation. According to the invention, the relative angle and the angle density information between the unmanned aerial vehicles are fully utilized to realize the number prediction of the unmanned aerial vehicles, the geometric relationship between the unmanned aerial vehicles and the relative position information thereof are utilized to position, a greedy algorithm is utilized to pay attention to the local solution so as to select the optimal strategy of formation and dynamically adjust, the dependence on external sensors and GPS technology is reduced, the condition of strong dependence on absolute positions is avoided, the unmanned aerial vehicle positioning method can adapt to fast movement and complex scenes, the positioning precision and the practicability of the unmanned aerial vehicles are improved, the calculation complexity of the unmanned aerial vehicle clusters in positioning and adjusting the formation is reduced, the positioning efficiency of the unmanned aerial vehicles is further improved, the real-time positioning requirement is met, and the unmanned aerial vehicle positioning method is suitable for the scenes of the unmanned aerial vehicle environment.

Additional features and advantages of the application will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the application. The objectives and other advantages of the application will be realized and attained by the structure particularly pointed out in the written description and claims hereof as well as the appended drawings.

Drawings

FIG. 1 is a flow chart of a purely azimuthal passive positioning method for an unmanned aerial vehicle according to the present application;

FIG. 2 is a flow chart illustrating the formation of a radial flight formation of an unmanned aerial vehicle according to the present application;

FIG. 3 is a schematic diagram of an ideal angle and an actual angle according to the present application;

FIG. 4 is a schematic diagram of an application scenario of a first positioning step according to the present application;

fig. 5 is a schematic diagram of an application scenario of a second positioning step proposed in the present application;

FIG. 6 is a diagram illustrating positioning adjustment according to the present application;

fig. 7 is a schematic diagram of a purely azimuthal passive positioning method of an unmanned aerial vehicle according to the present application.

Detailed Description

The present application will be described in further detail with reference to the drawings and examples, in order to make the objects, technical solutions and advantages of the present application more apparent. It should be understood that the specific embodiments described herein are for purposes of illustration only and are not intended to limit the scope of the application.

The application will be further described with reference to the drawings and specific examples. The described embodiments should not be taken as limitations of the present application, and all other embodiments that would be obvious to one of ordinary skill in the art without making any inventive effort are intended to be within the scope of the present application.

In the following description, reference is made to "some embodiments" which describe a subset of all possible embodiments, but it is to be understood that "some embodiments" can be the same subset or different subsets of all possible embodiments and can be combined with one another without conflict.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein is for the purpose of describing embodiments of the application only and is not intended to be limiting of the application.

Aiming at the problems and defects of the existing unmanned aerial vehicle positioning technology, the application provides an unmanned aerial vehicle positioning method and system based on a pure-azimuth passive positioning technology, which aim to solve the technical problems in unmanned aerial vehicle positioning and formation flight, in particular to the unmanned aerial vehicle positioning system under the conditions of no stable GPS signal, complex environment, dynamic scene and the like. The purely azimuthal passive positioning technique of the unmanned aerial vehicle has unique advantages over GPS, inertial navigation positioning and visual positioning techniques. The method has the outstanding advantages that electromagnetic silence, namely no electromagnetic signal is required to be emitted to the outside, and the method is beneficial to reducing the possibility of detection or interference of the unmanned aerial vehicle in a scene with high safety requirements. Secondly, autonomy and adaptability of the pure-azimuth passive positioning technology enable the unmanned aerial vehicle to carry out formation flight more autonomously and flexibly under the condition of not depending on a specific navigation signal source or visual reference. The unmanned aerial vehicle positioning device is positioned through the direction information, so that the position concealment of the unmanned aerial vehicle is improved, and the possibility of exposing the position information is reduced.

The invention aims to realize accurate positioning and formation control of the unmanned aerial vehicle in such challenging environments by introducing a radial pure-azimuth passive positioning unmanned aerial vehicle formation flight strategy based on geometric calculation and greedy algorithm; the core is how to utilize the geometric relation between unmanned aerial vehicles and dynamically adjust formation through greedy algorithm, thereby realizing that accurate positioning and formation flying are maintained under the condition that GPS signals are not needed.

The purely azimuthal passive positioning method of the unmanned aerial vehicle provided by the invention will be described below with reference to the accompanying drawings.

The method of the invention can be applied to the terminal, the server, software running in the terminal or the server, and the like. The terminal may be, but is not limited to, a tablet computer, a notebook computer, a desktop computer, etc. The server may be an independent physical server, a server cluster or a distributed system formed by a plurality of physical servers, or a cloud server providing cloud services, cloud databases, cloud computing, cloud functions, cloud storage, network services, cloud communication, middleware services, domain name services, security services, CDNs, basic cloud computing services such as big data and artificial intelligent platforms.

Referring to fig. 1, the method proposed by the present invention comprises the steps of:

s100, when the unmanned aerial vehicle cluster flies, acquiring the unmanned aerial vehicle with the circle center, constructing a circular flight orbit based on the unmanned aerial vehicle with the circle center, and determining a transmitter group belonging to the circular flight orbit and a plurality of receivers with unknown positions to be positioned.

It should be noted that, the transmitter group includes the centre of a circle unmanned aerial vehicle and the first unmanned aerial vehicle of current position and number information known and the many transmitters of current position known, and centre of a circle unmanned aerial vehicle is the transmitter that is located the centre of a circle of circular flight orbit, and first unmanned aerial vehicle is the transmitter that is close to circular flight orbit. Wherein, the distance between the first unmanned aerial vehicle and the circular flight orbit is smaller than the distance between the circular flight orbit and any transmitter.

It will be appreciated that a transmitter is defined as a drone that continuously transmits signals, and a receiver is a receiver that receives signals transmitted by a transceiver. Typically, the drone that needs to be positioned is a receiver. In the invention, unmanned aerial vehicles of the transmitter group are all unmanned aerial vehicles transmitting signals, namely, the center unmanned aerial vehicle and the first unmanned aerial vehicle are both transmitters.

S200, determining the number information of the transmitter unit, positioning and adjusting the positions of a plurality of receivers to be positioned according to the number information and the current position of the transmitter unit, and enabling each receiver to be positioned on a circular flight orbit when each receiver to be positioned finishes position positioning;

S300, judging whether other unmanned aerial vehicles which are not positioned exist in the unmanned aerial vehicle cluster; if yes, the unmanned aerial vehicle cluster is not completed in formation, and S400 is entered; if not, the unmanned plane cluster is finished forming, and the process goes to S500.

S400, returning to S100 by taking each receiver to be positioned as a circle center unmanned aerial vehicle;

s500, all unmanned aerial vehicles in the unmanned aerial vehicle cluster are located on corresponding circular flight tracks, and then radial flight formations of the unmanned aerial vehicle cluster are built.

Specifically, steps S100 to S200 correspond to single circle adjustment of a certain wheel, and the unmanned aerial vehicle to be positioned refers to an unmanned aerial vehicle participating in single circle adjustment of a current wheel, and after step S200, the unmanned aerial vehicle to be positioned is positioned at an ideal position and is in a positioned state.

Step S300 is used for judging whether the next round of single circle adjustment can be entered, and the remaining unmanned aerial vehicles which are not positioned in the unmanned aerial vehicle cluster in step S300 refer to unmanned aerial vehicles which are not involved in the single circle adjustment of the current round and are not positioned in the unmanned aerial vehicle cluster, and the meaning of the unmanned aerial vehicles is different from that of the unmanned aerial vehicles to be positioned.

When there are other unmanned aerial vehicles which do not participate in the single-circle adjustment of the current wheel and are not positioned in the unmanned aerial vehicle cluster, the method enters the step S400, the unmanned aerial vehicle to be positioned at the ideal position after the step S200 is used as a circle center unmanned aerial vehicle, the circle center unmanned aerial vehicle is updated, a new circular flight track is constructed by taking the new circle center unmanned aerial vehicle as the circle center, a new transmitter set and a new receiver to be positioned are further determined, and the method enters the new single-circle adjustment, namely returns to the step S100, and circulates.

When all the unmanned aerial vehicles are adjusted through the corresponding single circles, the step S500 is entered, all the unmanned aerial vehicles are in a positioned state, and the circulation is ended at the moment, so that the radial flying formation of the unmanned aerial vehicle cluster is formed.

In order to establish the problem of positioning unmanned aerial vehicles under the condition of conical formation, the invention considers the equidistant conical formation formed by a plurality of unmanned aerial vehicles to be converted into a circular formation problem by combining the condition that the distance between two adjacent unmanned aerial vehicles on each straight line is R when the adjacent unmanned aerial vehicles are at ideal positions, establishes a radial position adjustment model, and then solves the problem by utilizing a positioning adjustment model established by an unmanned aerial vehicle formation adjustment algorithm based on a geometric positioning algorithm and a greedy algorithm, wherein the specific implementation flow is as follows:

referring to fig. 2, first, a unmanned aerial vehicle is randomly selected to be in an ideal position, and the selected unmanned aerial vehicle is the unmanned aerial vehicle with the center of a circle and is denoted as number 0. After the circle center unmanned plane is selected, a circular track is constructed by taking R as a radius, wherein R is a preset value, and the R can be set according to actual conditions. False, falseThe set deviation is very small compared with the radius of the track, and at the moment, a plurality of unmanned aerial vehicles with position deviation fall near the track, and the unmanned aerial vehicles are all regarded as unmanned aerial vehicles with positions to be adjusted. Then, one unmanned aerial vehicle closest to the circular track is selected from a plurality of unmanned aerial vehicles which are close to the circular track and are to be adjusted to serve as a first unmanned aerial vehicle, the first unmanned aerial vehicle is marked as a No. 1 unmanned aerial vehicle, and other unmanned aerial vehicles are marked as Number machine (s)/(s)>Thereby constructing a transmitter group. In this way, a transmitter unit and a plurality of receivers to be positioned exist in a single circular flight orbit, and then the established geometric positioning algorithm and greedy algorithm are utilized to position and adjust the receivers to be positioned, and the adjustment is single circle adjustment according to one time. After each single circle adjustment, the adjusted unmanned aerial vehicle is regarded as returning to the ideal position, and the position of the unmanned aerial vehicle is not changed in the subsequent adjustment process. And after the single circle is adjusted, repeating the steps, and simultaneously taking each adjusted unmanned aerial vehicle as a circle center to generate a plurality of novel circle center unmanned aerial vehicles, and continuously adjusting the positions of the unmanned aerial vehicles radially outwards until the positions of all unmanned aerial vehicles are adjusted, and recovering to the ideal positions.

In one embodiment of the present application, the implementation process of determining the numbering information of the sender group in step S200 will be further described and illustrated. The position positioning and adjustment of the unmanned aerial vehicle are realized by depending on the number information of the transmitter unit, so that the number information of all unmanned aerial vehicles in the transmitter unit needs to be confirmed before the position positioning and adjustment of the unmanned aerial vehicle are carried out, and the step of determining the number information comprises the following steps:

And controlling the multiple transmitters, the circle center unmanned aerial vehicle and the first unmanned aerial vehicle to transmit numbering signals to any receiver to be positioned. And (3) regarding the transmitter with the transmitted number signal not carrying the corresponding number mark, recording the transmitter as an unknown number transmitter, and performing number prediction on the unknown number transmitter by using a Density-based spatial clustering (Density-Based Spatial Clustering of Applications with Noise, DBSCAN) algorithm to generate the number information of the unknown number transmitter. And for the transmitter with the corresponding number mark in the transmitted number signal, marking the signal as a known number transmitter, and determining the number information of the known number transmitter by using the number mark.

It should be noted that if and only if the number signal transmitted by the unmanned aerial vehicle with the number information carries the corresponding number identifier.

Further, the step of implementing the number prediction by the DBSCAN algorithm is as follows:

the method comprises the steps of firstly, obtaining ideal positions of a circle center unmanned aerial vehicle, a plurality of transmitters and a first unmanned aerial vehicle, and constructing an ideal angle matrix according to the ideal positions.

This embodiment assumes that: the ideal unmanned aerial vehicle formation is circular, and this formation comprises 10 unmanned aerial vehicles, and No. 0 unmanned aerial vehicle is located the centre of a circle and other unmanned aerial vehicles evenly distributed on the circumference this moment, and No. 0 unmanned aerial vehicle, no. 1 unmanned aerial vehicle's serial number is known, and The numbering of the numbering machine is unknown. To get->The numbering position of the numbering machine is obtained firstly, ideal positions of the circle center unmanned aerial vehicle, the multiple signalling machines and the first unmanned aerial vehicle are obtained, and a first ideal included angle and a second ideal included angle of each signalling machine are calculated based on the ideal positions. Referring to fig. 3 (a), an ideal angle matrix is constructed by the first ideal angle and the second ideal angle of each transmitter, and the straight line of the transmitter and the center unmanned plane is a first straight line when the transmitter set is located at an ideal position>The line where the transmitter and the receiver are located is a second line +.>The line where the transmitter and the first unmanned aerial vehicle are located is a third line +.>The following steps are:

the first ideal included angle isDefined as the first line +.>And a second straight line +>The included angle is formed. Namely, when the transmitter group is located at the desired position, +.>Number machine and->Straight line of the number machine and ∈ ->The included angle formed by the straight line where the machine number 0 and the machine number 0 are positioned is +.>。

The second ideal included angle isDefined as the third straight line +.>And a second straight lineThe included angle is formed. Namely, when the transmitter group is located at the desired position, +.>Number machine and->Straight line of the number machine and ∈ ->The included angle formed by the straight line where the machine number 1 and the machine number 1 are positioned is +. >。

The ideal angle matrix is shown in the following formula:

。

and secondly, acquiring the current positions of the circle center unmanned aerial vehicle, the unknown numbering transmitter and the first unmanned aerial vehicle, and constructing a numbering angle matrix according to the current positions and the ideal angle matrix.

In the case of the above assumption, the receiver is in a state of positional deviation in the actual situation, and the receiver cannot obtain the numbers of transmitters other than the 0-th and 1-th transmitters at first, but it can receive signals transmitted by other transmitters. Therefore, in this embodiment, the number signals emitted by the first unmanned aerial vehicle, the central unmanned aerial vehicle and the unknown number transmitter are used to determine the current positions of the unknown number transmitter, the central unmanned aerial vehicle and the first unmanned aerial vehicle, and the first actual included angle and the second actual included angle of the unknown number transmitter are calculated based on the current positions, so as to construct the number angle matrix through the first actual included angle, the second actual included angle and the ideal angle matrix. Referring to fig. 3 (b), in the case where the transmitter group is located at the current position (i.e., the actual position), a line in which the transmitter and the center unmanned plane are located is defined as a fourth lineThe line where the transmitter and the receiver are located is a fifth line +. >The line where the transmitter and the first unmanned aerial vehicle are located is a sixth line +.>The following steps are:

the first actual included angle isDefined as the fourth straight line +.>And a fifth straight line->The included angle is formed. Namely, when the transmitter group is located at the desired position, +.>Number machine and->Straight line of the number machine and ∈ ->The included angle formed by the straight line where the number machine and the number 0 machine are positioned is。

The second actual included angle isDefined as the sixth straight line +.>And a fifth straight line->The included angle formed, i.e. when the transmitter group is located in the current position, is recorded +.>Number machine and->Straight line of the number machine and ∈ ->The included angle formed by the straight line where the machine number 1 and the machine number 1 are positioned is。

The numbered angle matrix is shown in the following formula:

。

thirdly, carrying out numbering prediction by combining a numbering angle matrix with a DBSCAN algorithm to obtain the numbering information of the unknown numbering transmitter.

In the whole process of transmitting the number signal, the receiver in the position deviation state receives the information transmitted by the transmitter with unknown number but ideal position, the number 0 machine and the number 1 machine at the same time. In order to find the number of the unknown number sender, the present embodiment builds a number prediction algorithm based on the DBSCAN algorithm.

It should be noted that the DBSCAN algorithm is a clustering algorithm based on density, and the clustering algorithm continuously merges adjacent high-density areas according to the distribution density condition of area data, so that the algorithm does not need to preset the number of generated clusters, has good stray rejection capability and stability, and can find clusters with any shape. The DBSCAN algorithm has three points including core point, boundary point and noise point, and the thinking is that if one radius is The number of points inside the circle of (2) exceeds the density threshold +.>Then the center of the circle is marked as the core point, also known as the core object. If the number of points in the field at a certain point is smaller than the density threshold +.>But falls within the domain of the core point, which is defined as being centered around this point, ++>A circle field of radius is called a boundary point. Finally, the plurality of points are clustered into a plurality of clusters through a DBSCAN algorithm.

The embodiment enables the management of the signaling machineIs numbered asThe reception mechanism is named->，/>，/>，Namely, the unmanned aerial vehicle clusters excluding the unmanned aerial vehicle with the circle centers totally have 9 unmanned aerial vehicles, and a matrix is constructed>And number predicting it using DBSCAN algorithm. Specifically, first, basic parameters of the DBSCAN algorithm are defined, including a core point with a field radius of +.>The dot density threshold is +.>And a classification threshold. For the classification threshold, the unmanned aerial vehicle cluster of this embodiment has 9 unmanned aerial vehicles and 1 unmanned aerial vehicle in the center of a circle, and wherein 9 unmanned aerial vehicles include 1 unmanned aerial vehicle with known number information, so the classification threshold is defined as 8. Then, the matrix is->Is regarded as coordinate point +.>In addition to->A total of 9 coordinates are distributed on the same coordinate system. Then, a DBSCAN clustering algorithm is applied to threshold the density 2, radius->Increase from 0 when +.>In the radius of the field, the threshold value of the dot density reaches +.>And when the method is used, the points in the radius of the field and the core points are recorded as similar points together, clusters are formed, and the clusters are continuously clustered until all coordinate points are processed and classified into a classification threshold value through a DBSCAN algorithm, and then the clusters of 8 categories are obtained. It is noted that 7 clusters each contain only 1 coordinate point, which is +.>The method comprises the steps of carrying out a first treatment on the surface of the And only 1 cluster contains 2 coordinate points +.>And->This cluster is noted as a matching cluster. In matched clusters, by comparisonAnd->The index of the number information can be obtained, and the number prediction and identification of the unmanned aerial vehicle are realized.

The implementation procedure of the position location and adjustment of step S200 will be further described and illustrated in the following. The application realizes the position positioning and adjustment based on a geometric positioning algorithm and a greedy algorithm, and comprises the following specific realization steps:

s210, for each receiver to be positioned, controlling the transmitter set to transmit positioning signals to the receiver to be positioned, and positioning the receiver to be positioned by using the number information and the current position of the transmitter set to obtain a plurality of initial positions of the receiver to be positioned.

In the step, the center unmanned aerial vehicle, the first unmanned aerial vehicle and other transmitters transmit positioning signals to a receiver to be positioned, and the receiver to be positioned passively receives the positioning signals transmitted by the transmitter set. During positioning, any transmitter is selected randomlyThe unmanned aerial vehicle, the first unmanned aerial vehicle and the center unmanned aerial vehicle are used as unmanned aerial vehicles for transmitting positioning signals together, and the unmanned aerial vehicle is +.>. The number information and the position of the unmanned aerial vehicle transmitting the positioning signal are jointly calculated to obtain the +.>Initial positions. By sequentially adding each->And the number machine, the first unmanned aerial vehicle and the circle center unmanned aerial vehicle perform joint operation, so that a plurality of initial positions of the receiver to be positioned can be obtained.

It will be appreciated that the number of initial positions is the same as the number of drones in the sender group.

And S220, when a plurality of initial positions of all the receivers to be positioned are obtained, optimizing the initial positions of each receiver to be positioned in sequence to obtain the final position of each receiver to be positioned, so that each receiver to be positioned performs position adjustment based on the final position.

With reference to fig. 4 and 5, the implementation procedure of the position location of step S210 will be further described and explained below. Fig. 4 is a schematic view of an application scenario of a first positioning step, fig. 5 is a schematic view of an application scenario of a second positioning step, and it is assumed that a drone cluster includes four drones, one of which is located at a center of a circle, and is named O; two other two The unmanned aerial vehicle is arranged on a circle taking O as a circle center and is respectively named as A and B, and corresponds to the first unmanned aerial vehicle and the second unmanned aerial vehicleA transmitter; the remaining aircraft is located near the distance circle, designated G, which is the receiver to be located. Wherein the radius of the circle is known and denoted as R. In the unmanned aerial vehicle cluster, O, A, B is used for transmitting signals, and is called a transmitter for short; and G is forced to receive signals, simply called receivers. After a round of signal transmission, G can obtain its angle information with a and B, O and A, O and B, and B can also obtain its angle information with O and G, O and a.

The step S210 specifically includes the following steps:

s211, obtaining the first of the transmitter groupTransmitter(s)>In->Unmanned aerial vehicle with transmitter, first unmanned aerial vehicle and centre of a circle unmanned aerial vehicle as transmitting positioning signal, according to +.>And calculating the numbering information and the current position of the transmitter, the first unmanned aerial vehicle and the center unmanned aerial vehicle to obtain a first angle set of the unmanned aerial vehicle cluster.

It should be noted that, referring to fig. 4 and fig. 5, the first angle set includes a first included angle, a second included angle, and a third included angle, and when the transmitter set is located at the current position, a line where the receiver to be located and the first unmanned aerial vehicle are located is a seventh line Receiver to be located and +.>The straight line of the transmitter is eighth straight lineLine->The line of the receiver to be positioned and the circle center unmanned plane is a ninth line +.>The following steps are:

the first included angle is a seventh straight lineAnd eighth straight line->The included angle is recorded as->. Namely, G forms an angle with A and B +.>For the first included angle->。

The second included angle is a ninth straight lineAnd a seventh straight line->The included angle is recorded as->. Namely, G forms an angle with O and A +.>Is a second included angle->。

The third included angle is a ninth straight lineAnd eighth straight line->The included angle is recorded as->. Namely, G forms an angle with O and B +.>Is a third included angle->。

S212, determining a positioning step of the receiver to be positioned according to the first angle set, and positioning the receiver to be positioned by utilizing the positioning step to obtain the first receiver to be positionedAn initial position.

The positioning step includes either one of the first positioning step or the second positioning step.

It will be appreciated that the firstThe initial position is when->The initial position of the receiver to be positioned is calculated when the transmitter is used as the unmanned aerial vehicle for transmitting the positioning signal.

In this embodiment, the correlation among the first included angle, the second included angle and the third included angle determines the positioning mode of the receiver to be positioned, and the implementation process of the determining positioning step is as follows:

And when the second included angle and the third included angle are smaller than the first included angle, acquiring the first positioning step as the positioning step of the receiver to be positioned. I.e. when meetingIs greater than->、/>Is greater than->Or->Is greater than->And->In any one of the above, the first positioning step is used as the positioning step of the receiver to be positioned.

Or when the second included angle and/or the third included angle are/is larger than the first included angle, the second positioning step is obtained as the positioning step of the receiver to be positioned. I.e. when meetingIs greater than->And/or +.>Is greater than->And when the receiver is positioned, the second positioning step is used as the positioning step of the receiver to be positioned.

S213, orderReturning to S211 until the calculation of +_for the receiver to be located>Initial positions.

Further, the implementation procedure for implementing the positioning of the receiver to be positioned by using the positioning step in step S212 includes the following steps:

when the first positioning step is used for positioning the receiver to be positionedWhen the step is carried out, the first positioning step is utilized to position the receiver to be positioned, and the first receiver to be positioned is obtainedAn initial position;

or when the second positioning step is used as the positioning step of the receiver to be positioned, the receiver to be positioned is positioned by using the second positioning step to obtain the first receiver to be positioned An initial position.

The implementation of the first positioning step and the second positioning step will be described in detail below with reference to fig. 4 and 5.

First is a first positioning step. When the first positioning step is used as the positioning step of the receiver to be positioned, the distance between the center unmanned aerial vehicle and the first unmanned aerial vehicle is used as the positioning radius, fourth angle information is obtained, and the distance between the receiver to be positioned and the center unmanned aerial vehicle is calculated according to the first angle set, the fourth angle information and the positioning radius, so that the first receiver to be positioned is obtainedAn initial position.

Referring to fig. 4, when the transmitter group is located at the current position, the straight line where the center unmanned aerial vehicle and the first unmanned aerial vehicle are located is a tenth straight lineCenter unmanned plane and +.>The line of the transmitter is eleventh line +.>The following steps are: the fourth included angle is tenth straight line +.>And eleventh straight line->The included angle is recorded as->. Namely, A forms an angle with O and B +.>Is a fourth included angle->。

In the embodiment of the present invention, the first positioning step is applicable to a quadrilateral or triangle with OG as a midline, such as a triangle AGB with OG as a midline in fig. 4 (a), and a quadrilateral AGBO with OG as a midline in fig. 4 (b), which are both applicable scenarios belonging to the first positioning step. The specific positioning principle of the first positioning step according to the embodiment of the present invention will be described below by taking the case (b) of fig. 4 as an example, taking OG as the distance between O and G, and R as the positioning radius, where the specific positioning principle is as follows:

It is known that ao=bo=r,. At->And->Is obtained by sine theorem:

，/>；

in quadrilateral AOBG, the sum of the interior angles of the quadrilateral is 360 degrees:

。

a and B are ideal points on the circumference, respectively, and once the number of the drone is determined, the position on the circumference to which it corresponds is determined, although the selected drone is changing.Is the fourth included angle, i.e.)>The value can be obtained from the known position information of a and B. The numbers of the two unmanned aerial vehicles arranged on the circumference are respectively a and b in anticlockwise order, and then:. In addition, in the case of fig. 4 (a), there are: />Is the angle subtended by arc AB.

The distance between the center unmanned aerial vehicle and the receiver to be positioned can be immediately solved by simplifying the above formula, and the following formula is shown:。

and secondly, a second positioning step. And when the second positioning step is used as the positioning step of the receiver to be positioned, the distance between the center unmanned aerial vehicle and the first unmanned aerial vehicle is used as the positioning radius, and a fourth included angle and a second angle set of the unmanned aerial vehicle cluster are obtained. According to the second angle set, the fourth included angle and the positioning radius, calculating to obtain the distance between the receiver to be positioned and the circle center unmanned aerial vehicle, and further obtaining the first receiver to be positioned An initial position.

It should be noted that, referring to fig. 5, the second angle set includes a fifth included angle and a sixth included angle, where the transmitter group is located at the current position, the first angle setTransmitter and method for transmitting dataThe first unmanned aerial vehicle is the twelfth straight line +.>The following steps are: the fifth included angle is the eleventh straight line +.>And eighth straight line->The included angle is recorded as->First->The line of the transmitter and the center unmanned plane is eleventh line +.>First->The transmitter and the receiver to be positioned are eighth straight line +.>. Namely, B forms an angle with O and G +.>Is a fifth included angle->。

The sixth included angle is the twelfth straight lineAnd eleventh straight line->The included angle formed by the straight line is recorded as. Namely, B forms an angle with O and A +.>Is a sixth included angle->。

In the embodiment of the present invention, the second positioning step is applicable to a quadrilateral or triangle with OG as a side, for example, fig. 5 (a) is a triangle OGB with OG as a side, and for example, fig. 5 (b) is a quadrilateral ago with OG as a side, which are both application scenarios belonging to the second positioning step. The positioning principle of the second positioning step according to the embodiment of the present invention will be described below by taking the case (B) of fig. 5 as an example, taking R as a positioning radius, taking OG as a distance between O and G, taking OA as a distance between O and a, and taking OB as a distance between O and B, where the specific positioning principle is as follows:

Known ao=bo=r, whereAnd->Is obtained by sine theorem:

，/>；

the relationship that the sum of internal angles of the triangles is 180 degrees and opposite angles is equal can be obtained by:

，

a and B are ideal points on the circumference, respectively, and once the number of the drone is determined, the position on the circumference to which it corresponds is determined, although the selected drone is changing.Is the fourth included angle, i.e.)>The value can be obtained from the known position information of a and B. The numbers of the two unmanned aerial vehicles arranged on the circumference are respectively a and b in anticlockwise order, and then:. If the case of fig. 5 (a) is referred to as follows: />Is the angle subtended by arc AB.

The distance between the center unmanned aerial vehicle and the receiver to be positioned can be immediately solved by simplifying the above formula, and the following formula is shown:，

。

when the distance between the receiver to be positioned and the circle center unmanned aerial vehicle is obtained, the obtained distance and various included angles are converted through geometrical operation again, and then a certain initial position of the receiver to be positioned can be obtained.

The specific implementation procedure of the position adjustment in step S220 will be further described and illustrated in the following. The step S220 specifically includes the following steps:

s221, acquiring an ideal position and a plurality of initial positions of each receiver to be positioned.

In the step S210, the unmanned aerial vehicle cluster includes a plurality of transmitters, namelyNumber machine, any frame->The signal machine, the first unmanned aerial vehicle and the unmanned aerial vehicle with the circle center are jointly used as unmanned aerial vehicles for transmitting positioning signals, and initial positioning is carried out on receivers to be positioned one by one to obtain +.>The +.f. of the receiver to be positioned when the drone is the drone transmitting the positioning signal>An initial position. Wherein the receiver to be positioned is +.>No. H of machine>The initial position is marked as->The receiver to be positioned is +>The ideal position of the numbering machine is recorded as，/>，/>。

S222, calculating an adjustment error of each transmitter based on the ideal position and a plurality of initial positions of each receiver to be positioned, and taking the transmitter with the smallest adjustment error as a reference transmitter.

Further, referring to fig. 6, forThe number machine is used as the unmanned aerial vehicle for transmitting the positioning signal, and the step for calculating the adjustment error is specifically as follows:

first, the ideal position and the th of each receiver to be positioned are calculatedThe distance between the initial positions is taken as +.>The error distance of the numbering machine is shown in the following formula:

。

then, according to the number of receivers to be positioned, the method comprises the following steps ofSumming error distances of the numbering machines to generate +.>The adjustment error of the numbering machine is shown in the following formula:

。

S223, for each receiver to be positioned, taking the initial position obtained when the reference transmitter is taken as the unmanned aerial vehicle for transmitting the positioning signal as the final position of the receiver to be positioned, and controlling the receiver to be positioned to carry out position adjustment based on the final position by a greedy algorithm, so that the receiver to be positioned is positioned at an ideal position.

Further, the process of controlling the receiver to be positioned to adjust the position based on the final position by using the greedy algorithm specifically comprises the following steps:

the first step, calculating a seventh included angle and an eighth included angle of the receiver to be positioned, which are simulated to fly in all directions by a straight line with a fixed flight distance.

The directions of the simulated fly-in are defined as. The seventh included angle is marked as->It means that when the transmitter set is located at the ideal position, the reference transmitter and the center unmanned plane are located on the straight line and the reference transmitter and the flying direction +.>Included angle formed by the straight line of the receiver to be positioned. The eighth included angle is marked as->It means that when the transmitter group is located at the ideal position, the reference transmitter and the first unmanned aerial vehicle are located on the straight line and the reference transmitter and the flying direction +.>Included angle formed by the straight line of the receiver to be positioned.

The second step, calculating a loss function according to the seventh included angle, the eighth included angle, the first ideal included angle and the second ideal included angle, wherein the loss function is shown in the following formula:，

wherein,for the first ideal angle, +>For the second ideal angle->As a loss function.

Thirdly, a greedy algorithm is used for solving the loss function to obtain a current minimum loss function, the receiver to be positioned is controlled to go to the direction of the minimum loss function, the simulated flight direction is updated, and the receiver to be positioned returns to the first step until reaching an ideal position.

The principle and implementation of the technical solution of the present application will be explained below by way of an example.

Referring to fig. 7, in the unmanned aerial vehicle cluster, first, a unmanned aerial vehicle is randomly selected to be regarded as a state in an ideal position, and the selected unmanned aerial vehicle is the unmanned aerial vehicle with a circle center and is marked as a number 0 unmanned aerial vehicle. After the circle center unmanned plane is selected, a circular track is constructed by taking R as a radius, wherein R is a preset value and can be according to realityThe situation is set. The deviation is assumed to be small compared with the radius of the track, and a plurality of unmanned aerial vehicles with position deviation fall near the track and are all considered to be unmanned aerial vehicles with positions to be adjusted. Then, one unmanned aerial vehicle closest to the circular track is selected from a plurality of unmanned aerial vehicles which are close to the circular track and are to be adjusted to serve as a first unmanned aerial vehicle, the first unmanned aerial vehicle is marked as a No. 1 unmanned aerial vehicle, and other unmanned aerial vehicles are marked as Number machine (s)/(s)>Thereby constructing a transmitter group. Thus, there are a transmitter group and a plurality of receivers to be positioned in a single circular flight path.

In the single circle adjustment process, the ideal number of the transmitter is set asThe reception mechanism is named->，/>，，/>The invention uses the serial number and the position of the transmitter group to locate and adjust the position of the receiver to be located. For a sender without numbering information, a DBSCAN algorithm is utilized to predict the numbering of the sender; and the sender with the numbering information can directly extract the numbering information.

And then, the position of the receiver to be positioned is positioned and adjusted by using a geometric positioning algorithm and a greedy algorithm. During positioning, any transmitter is selected randomlyUnmanned number machine and circle centerThe unmanned aerial vehicle and the first unmanned aerial vehicle are used as unmanned aerial vehicles for transmitting positioning signals together, and the number information of the unmanned aerial vehicles for transmitting the positioning signals is subjected to joint calculation to obtain the receiver to be positioned ∈>Is>Initial positions. By sequentially adding each->The combination operation of the numbering machine, the circle center unmanned aerial vehicle and the first unmanned aerial vehicle is carried out, and the receiver to be positioned can be obtained>Is->The initial positions are the implementation of the geometric positioning algorithm.

Thereafter, in a plurality of receivers to be positionedOn the basis of the initial positions, each frame +.>The signal machine is used as an adjustment error when the unmanned aerial vehicle transmits the positioning signal, the reference signal machine is determined by utilizing the adjustment error, and the position of the receiver to be positioned is adjusted and controlled by a greedy algorithm.

After each single circle adjustment, the adjusted unmanned aerial vehicle is regarded as returning to the ideal position, and the position of the unmanned aerial vehicle is not changed in the subsequent adjustment process. And after the single circle is adjusted, repeating the steps, and simultaneously taking each adjusted unmanned aerial vehicle as a circle center to generate a plurality of novel circle center unmanned aerial vehicles, and continuously adjusting the positions of the unmanned aerial vehicles radially outwards until the positions of all unmanned aerial vehicles are adjusted, and recovering to the ideal positions.

The technical core of the method is how to utilize the geometric relation between unmanned aerial vehicles and dynamically adjust formation through a greedy algorithm, so that accurate positioning and formation flying are maintained under the condition that GPS signals are not needed. The technical method belongs to the fields of unmanned aerial vehicle autonomous navigation, optimization algorithm, formation control and the like. The method solves the positioning problem by means of geometric calculation, and simultaneously utilizes a greedy algorithm to realize dynamic formation adjustment, thereby innovatively solving the limitation of the traditional positioning and formation method under a complex environment. By combining the methods, the method provides a new direction for the progress of unmanned aerial vehicle technology, so that the unmanned aerial vehicle can still realize accurate positioning and collaborative flight under the GPS-free environment, and the application range of the prior art is expanded.

The invention can provide the following technical effects:

1. while conventional drone positioning methods are typically implemented based on known GPS signals or other sensor data, the present invention uses DBSCAN algorithm to matrix angle informationAnd (3) performing density clustering, and dividing the ideal angle and the actual angle into the same cluster to form the basis of number prediction. According to the technical scheme of number prediction and identification, relative angle and angle density information between unmanned aerial vehicles are fully utilized through a clustering and density estimation technology, instead of GPS position information, the number of the unmanned aerial vehicles can be predicted according to the angle information between the unmanned aerial vehicles under the condition that accurate position information is not available, and the method is suitable for a GPS-free environment and is not limited by known positions.

2. The method is different from the traditional method for realizing the positioning of the unmanned aerial vehicle by depending on GPS or other sensor data, the receiver to be positioned is positioned based on a geometric positioning algorithm, the geometric relationship between unmanned aerial vehicles such as polygons, triangles and the like and the relative position information thereof are fully utilized for positioning, the geometric calculation error is considered, the effective positioning result correction is carried out, the dependence on an external sensor is reduced, the condition of strong dependence on the absolute position is avoided, and the method is particularly suitable for the condition of unstable signals in the environment.

3. Different from the traditional unmanned aerial vehicle positioning method based on path planning, the method carries out optimizing and adjusting on the position of the receiver to be positioned based on a greedy algorithm, focuses on local solution, selects the unmanned aerial vehicle position adjusting mode which is most beneficial to the stability and the compactness of formation by considering the optimal strategy in each step of selection, dynamically adjusts the formation structure according to the position and the state of the unmanned aerial vehicle in formation, so that the formation structure is more compact and coordinated, realizes the dynamic adjustment of the unmanned aerial vehicle in circular formation, achieves better formation effect, and is suitable for dynamic environment and real-time adjustment.

4. Different from the traditional positioning adjustment method based on the target points, the method selects the radial formation as the flight formation of the unmanned aerial vehicle, can select a proper central point according to the formation requirement, forms radial distribution around the central point by the unmanned aerial vehicle on the basis of a certain central point, and enables the unmanned aerial vehicle to gradually adjust the positions of the unmanned aerial vehicle in radial distribution so as to achieve the adjustment target of the formation shape, thereby realizing the adjustment of the formation structure, and being applicable to different target points and flexible formation requirements.

In summary, the invention establishes a reasonable and scientific geometric model through the discussion of various geometric relations which possibly exist, and realizes the effective positioning of the receiver on the premise of keeping electromagnetic silence as much as possible. Meanwhile, the accuracy of the model is measured by accumulating a plurality of error values by adopting accumulated errors, so that the accuracy of the positioning adjustment model can be displayed maximally. The unmanned aerial vehicle positioning strategy provided by the invention has a wider application range, and particularly, the radial position adjustment model based on the circle is adopted, so that the efficiency and the accuracy of positioning can be effectively improved by adopting the radial position adjustment model when the unmanned aerial vehicle group with a large sample flies in a conical formation.

In addition, the embodiment of the application also provides a pure azimuth passive positioning system of the unmanned aerial vehicle, which comprises the following components:

the data processing module has the functions of: when the unmanned aerial vehicle clusters fly, the circle center unmanned aerial vehicle is obtained, a circular flight orbit is built based on the circle center unmanned aerial vehicle, and a transmitter unit belonging to the circular flight orbit and a plurality of receivers with unknown positions to be positioned are determined.

The number prediction module has the functions of: determining the number information of a transmitter unit;

the positioning adjustment module has the functions that: positioning the positions of a plurality of receivers to be positioned according to the number information and the current position of the transmitter unit, and when each receiver to be positioned finishes position positioning, enabling each receiver to be positioned on a circular flight orbit;

the judging control module has the functions that: judging whether other unmanned aerial vehicles which are not positioned exist in the unmanned aerial vehicle cluster, when the unmanned aerial vehicles exist in the unmanned aerial vehicle cluster, taking each receiver to be positioned as a circle center unmanned aerial vehicle, returning to the data processing module until all unmanned aerial vehicles in the unmanned aerial vehicle cluster are positioned in corresponding circular flight tracks, and further constructing the radial flight formation of the unmanned aerial vehicle cluster.

The content in the method embodiment is applicable to the system embodiment, the functions specifically realized by the system embodiment are the same as those of the method embodiment, and the achieved beneficial effects are the same as those of the method embodiment.

The terms "first," "second," "third," "fourth," and the like in the description of the application and in the above figures, if any, are used for distinguishing between similar objects and not necessarily for describing a particular sequential or chronological order. It is to be understood that the data so used may be interchanged where appropriate such that the embodiments of the application described herein may be implemented, for example, in sequences other than those illustrated or otherwise described herein. Furthermore, the terms "comprises," "comprising," and "having," and any variations thereof, are intended to cover a non-exclusive inclusion, such that a process, method, system, article, or apparatus that comprises a list of steps or elements is not necessarily limited to those steps or elements expressly listed or inherent to such process, method, article, or apparatus.

It should be understood that in the present application, "at least one (item)" means one or more, and "a plurality" means two or more. "and/or" for describing the association relationship of the association object, the representation may have three relationships, for example, "a and/or B" may represent: only a, only B and both a and B are present, wherein a, B may be singular or plural. The character "/" generally indicates that the context-dependent object is an "or" relationship. "at least one of" or the like means any combination of these items, including any combination of single item(s) or plural items(s). For example, at least one (one) of a, b or c may represent: a, b, c, "a and b", "a and c", "b and c", or "a and b and c", wherein a, b, c may be single or plural.

In the several embodiments provided in the present application, it should be understood that the disclosed system, apparatus and method may be implemented in other manners. For example, the apparatus embodiments described above are merely illustrative, e.g., the division of the units is merely a logical function division, and there may be additional divisions when actually implemented, e.g., multiple units or components may be combined or integrated into another system, or some features may be omitted or not performed. Alternatively, the coupling or direct coupling or communication connection shown or discussed with each other may be an indirect coupling or communication connection via some interfaces, devices, or units, which may be in electrical, mechanical, or other forms.

The units described as separate units may or may not be physically separate, and units shown as units may or may not be physical units, may be located in one place, or may be distributed on a plurality of network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

In addition, each functional unit in the embodiments of the present application may be integrated in one processing unit, or each unit may exist alone physically, or two or more units may be integrated in one unit. The integrated units may be implemented in hardware or in software functional units.

The integrated units, if implemented in the form of software functional units and sold or used as stand-alone products, may be stored in a computer readable storage medium. Based on such understanding, the technical solution of the present application may be embodied essentially or in part or all of the technical solution or in part in the form of a software product stored in a storage medium, including instructions for causing a computer device (which may be a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the method according to the embodiments of the present application. And the aforementioned storage medium includes: read-Only Memory (ROM), random access Memory (Random Access Memory, RAM), magnetic or optical disk, and other various media capable of storing program codes.

The step numbers in the above method embodiments are set for convenience of illustration, and the order of steps is not limited in any way, and the execution order of the steps in the embodiments may be adaptively adjusted according to the understanding of those skilled in the art.

Claims

1. The pure-azimuth passive positioning method of the unmanned aerial vehicle is characterized by comprising the following steps of:

when the rest unmanned aerial vehicles exist in the unmanned aerial vehicle cluster, taking each receiver to be positioned as a circle center unmanned aerial vehicle, and returning to the step of building a circular flight orbit based on the circle center unmanned aerial vehicle until all unmanned aerial vehicles in the unmanned aerial vehicle cluster are positioned on the corresponding circular flight orbit, thereby building a radial flight formation of the unmanned aerial vehicle cluster;

Wherein the step of determining the numbering information of the sender unit comprises:

controlling a plurality of transmitters, the circle center unmanned aerial vehicle and the first unmanned aerial vehicle to transmit serial number signals to any receiver to be positioned;

for the sender with the transmitted number signal not carrying the corresponding number mark, recording the sender as an unknown number sender, and carrying out number prediction on the unknown number sender by using a DBSCAN algorithm to generate the number information of the unknown number sender;

for the sender with the corresponding number mark carried by the transmitted number signal, recording the number signal as a known number sender, and determining the number information of the known number sender by using the number mark;

the method for positioning and adjusting the positions of the multiple receivers to be positioned according to the serial number information and the current position of the transmitter group comprises the following steps:

for each receiver to be positioned, controlling the transmitter set to transmit positioning signals to the receiver to be positioned, and positioning the receiver to be positioned by using the number information and the current position of the transmitter set to obtain a plurality of initial positions of the receiver to be positioned;

when a plurality of initial positions of all the receivers to be positioned are obtained, optimizing the initial positions of each receiver to be positioned in sequence to obtain the final position of each receiver to be positioned, so that each receiver to be positioned is subjected to position adjustment based on the final position;

Wherein, for each receiver to be positioned, the step of positioning the receiver to be positioned by using the number information and the current position of the transmitter set to obtain the initial position of the receiver to be positioned comprises:

obtain the first of the transmitter groupTransmitter(s)>In->The transmitter, the first unmanned aerial vehicle and the center unmanned aerial vehicle are used as unmanned aerial vehicles for transmitting the positioning signals according to the +.>The method comprises the steps that numbering information and the current position of a transmitter, a first unmanned aerial vehicle and a circle center unmanned aerial vehicle are calculated to obtain a first angle set of an unmanned aerial vehicle cluster;

determining a positioning step of the receiver to be positioned according to the first angle set, and positioning the receiver to be positioned by utilizing the positioning step to obtain a first receiver to be positionedInitial position, the->The initial position is when->The position of the receiver to be positioned is calculated when the transmitter is used as an unmanned aerial vehicle for transmitting positioning signals;

order theReturn acquisitionNo. of transmitter group>A step of the transmitter until the calculation of +.>Initial positions;

wherein the first set of angles comprises:

a first included angle is a straight line where the receiver to be positioned and the first unmanned aerial vehicle are and the receiver to be positioned and the first unmanned aerial vehicle are when the transmitter set is positioned at the current position The included angle formed by the straight line where the transmitter is positioned;

the second included angle is an included angle formed by a straight line where the receiver to be positioned and the first unmanned aerial vehicle are positioned and a straight line where the receiver to be positioned and the unmanned aerial vehicle with the circle center are positioned when the transmitter set is positioned at the current position;

a third included angle is a straight line where the receiver to be positioned and the center unmanned plane are located and the receiver to be positioned and the first included angle when the transmitter set is located at the current positionThe included angle formed by the straight line where the transmitter is located.

2. The method for purely azimuthal passive positioning of unmanned aerial vehicle according to claim 1, wherein the step of using DBSCAN algorithm to predict the numbering of the unknown numbering transmitter, generating the numbering information of the unknown numbering transmitter comprises:

acquiring ideal positions of a plurality of transmitters, the circle center unmanned aerial vehicle and the first unmanned aerial vehicle, and constructing an ideal angle matrix according to the ideal positions;

acquiring the current positions of the unknown number transmitter, the circle center unmanned aerial vehicle and the first unmanned aerial vehicle, and constructing a number angle matrix according to the current positions and the ideal angle matrix;

and carrying out numbering prediction by combining the numbering angle matrix with a DBSCAN algorithm to obtain the numbering information of the unknown numbering transmitter.

3. The purely azimuthal passive positioning method of claim 1, wherein the positioning step comprises either one of a first positioning step or a second positioning step; the step of determining the positioning step of the receiver to be positioned according to the first angle set comprises the steps of:

when the second included angle and the third included angle are smaller than the first included angle, the first positioning step is obtained as a positioning step of the receiver to be positioned; or,

and when the second included angle and/or the third included angle are/is larger than the first included angle, acquiring the second positioning step as the positioning step of the receiver to be positioned.

4. The method for purely azimuthal passive positioning of unmanned aerial vehicle according to claim 3, wherein when a first positioning step is used as the positioning step of the receiver to be positioned, the receiver to be positioned is positioned by using the first positioning step to obtain the first receiver to be positionedThe step of initial position includes:

when the first positioning step is used as the positioning step of the receiver to be positioned, the distance between the circle center unmanned aerial vehicle and the first unmanned aerial vehicle is used as a positioning radius, and a fourth included angle is obtained;

According to the first angle set, the fourth included angle and the positioning radius, calculating to obtain the distance between the receiver to be positioned and the circle center unmanned plane;

obtaining the first receiver to be positioned according to the distance between the receiver to be positioned and the circle center unmanned aerial vehicleAn initial position.

5. The method for purely azimuthal passive positioning of unmanned aerial vehicle according to claim 4, wherein when the second positioning step is used as the positioning step of the receiver to be positioned, the receiver to be positioned is positioned by using the first positioning step to obtain the first receiver to be positionedThe step of initial position includes:

when the second positioning step is used as the positioning step of the receiver to be positioned, the distance between the center unmanned aerial vehicle and the first unmanned aerial vehicle is used as a positioning radius, and a fourth included angle and a second angle set of the unmanned aerial vehicle cluster are obtained;

according to the second angle set, the fourth included angle and the positioning radius, calculating to obtain the distance between the receiver to be positioned and the circle center unmanned plane;

obtaining the first receiver to be positioned according to the distance between the receiver to be positioned and the circle center unmanned aerial vehicle An initial position.

6. The method for purely azimuthal passive positioning of an unmanned aerial vehicle according to claim 1, wherein the step of sequentially optimizing a plurality of initial positions of each receiver to be positioned to obtain a final position of each receiver to be positioned so that each receiver to be positioned performs position adjustment based on the final position thereof comprises:

acquiring an ideal position and a plurality of initial positions of a receiver to be positioned, calculating an adjustment error of each transmitter based on the ideal position and the plurality of initial positions of each receiver to be positioned, and taking the transmitter with the smallest adjustment error as a reference transmitter;

for each receiver to be positioned, taking the initial position obtained when the reference transmitter is taken as the unmanned aerial vehicle for transmitting the positioning signal as the final position of the receiver to be positioned, and controlling the receiver to be positioned to carry out position adjustment based on the final position by a greedy algorithm.

7. A purely azimuthal passive positioning system for an unmanned aerial vehicle, applied to a purely azimuthal passive positioning method for an unmanned aerial vehicle according to any of claims 1 to 6, comprising: