A method for searching for a UAV without a network

Abstract

The application relates to a method for searching for a UAV under a network-free condition, which comprises the following steps: when a first UAV normally flies, a communication module sends coordinate information collected by a GNSS module to a server back end and stores the GNSS coordinate point; after a crash accident occurs, a current network state and GNSS coordinate information are acquired; under a network state, if the GNSS coordinate information is lost, a UWB module is started and a user is waited for to be controlled; otherwise, the crash point GNSS coordinate information is reported on a network and a user instruction is waited for; under a network-free state, the first UAV automatically opens the UWB module to search, a second UAV is used and a base station is installed to finally acquire a GNSS coordinate point nearby, a communication connection with the first UAV is generated, the base station acquires communication feedback information in real time through a software and hardware interface, the first UAV is positioned and searched based on the communication feedback information, and position information of the first UAV is obtained.

Description

Technical Field

[0001] This invention relates to a method for locating drones in the absence of a network, belonging to the field of drone search technology. Background Technology

[0002] With the large-scale application of drones for power transmission line inspections, maintenance personnel are increasingly using drones for operations. However, due to the complex environment at the site, drones often crash due to various reasons. The small size of drones, dense vegetation, and the fact that some areas are remote and often without network coverage make locating crashed drones difficult.

[0003] To address the current problems, invention patent CN113945960A discloses a method and system for locating and positioning unmanned aerial vehicles (UAVs). The specific solution is as follows: "Acquire local location information and target location information sent by the UAV, where the target location information is the UAV's location information; calculate the azimuth angle between the local location and the UAV based on the local location information and the target location information; when the distance between the UAV and the local location is less than a preset distance, acquire the distance measurement information between the local location and the UAV, and confirm the search radius based on the distance measurement information; determine the UAV's position based on the azimuth angle and the search radius." This prior art, by acquiring the position coordinates of the local end and the UAV, calculating the azimuth angle, and obtaining the distance measurement data between the two ends, can further confirm the UAV's positioning, and the entire process is accurate. However, this prior art has problems such as a large distance between the local end and the UAV, unstable wireless communication signals, inflexible search methods, the need for a combination of wireless communication and satellite communication, and the requirement for more hardware, resulting in higher costs.

[0004] To address this issue, the present invention developed a novel drone retrieval hardware and applied a retrieval algorithm to enable another drone to locate a crashed drone in the absence of a network. Field verification has shown that this device can avoid the problem of drones being lost after crashing and improve the efficiency of on-site retrieval. Summary of the Invention

[0005] To address the problems existing in the prior art, this invention proposes a method for locating drones in the absence of a network, which can avoid the problem of drones being lost after crashing and improve the efficiency of on-site search.

[0006] The technical solution of the present invention is as follows:

[0007] On the one hand, the present invention provides a method for locating drones in the absence of a network, comprising the following steps:

[0008] When the first UAV is flying normally, it sends the coordinate information collected by the GNSS module to the server backend for storage through the communication module, thus obtaining the GNSS coordinate points;

[0009] After the first UAV crashes, obtain the current network status and GNSS coordinate information of the first UAV.

[0010] If the first UAV is currently connected to the network and its GNSS coordinates are lost, the UWB module installed on the first UAV will be activated and the UAV will wait for user control. Otherwise, the UAV will report the GNSS coordinates of the crash site via the network and wait for user instructions.

[0011] Currently, when the first UAV is in a network-free state, it automatically activates the UWB module installed on its fuselage to search for a location. The second UAV is then used, and a base station is installed near the last GNSS coordinate point obtained during the UAV's normal flight. When the second UAV establishes a communication connection with the first UAV's UWB module, the base station obtains the communication feedback information from the second UAV in real time through the hardware and software interface. Based on the communication feedback information, the base station locates and searches for the first UAV to obtain its position information.

[0012] Preferably, the communication feedback information includes the RTK module information and UWB module information of the second UAV;

[0013] The RTK module information includes the real-time latitude, longitude, and altitude information of the second UAV; the UWB module information includes the latitude, longitude, altitude information of the second UAV, and the distance information between the second UAV and the first UAV when the second UAV is connected to the first UAV.

[0014] Preferably, the step of locating and searching the first UAV based on communication feedback information to obtain the location information of the first UAV specifically includes:

[0015] Let the latitude and longitude coordinates of the second UAV be... The latitude and longitude coordinates of the second UAV are transformed to obtain the corresponding three-dimensional coordinates. The specific transformation formula is as follows:

[0016]

[0017] in, It is the eccentricity of the ellipsoid N is the radius of curvature of the ellipse. a represents the distance along the Earth's major axis; b represents the distance along the Earth's minor axis. , They are latitude and longitude, respectively; For height; The distance returned by the UWB module;

[0018] Let the three-dimensional coordinates D of the first UAV be... The distance value returned by the UWB module is obtained by solving the equation. The specific solution to the equation is as follows:

[0019]

[0020] in, , , These are the values ​​of the three-dimensional coordinates converted from the latitude and longitude coordinates of the second UAV using a transformation formula;

[0021] Calculate the three-dimensional coordinates corresponding to the i latitude and longitude coordinates of the second UAV. , , And calculate the average distance from the great circle to the three-dimensional coordinate D: Calculate the average distance between the i-th three-dimensional coordinates of the second UAV and the three-dimensional coordinates D of the first UAV. The formula for calculating the average distance is as follows:

[0022]

[0023] Substitute the formula for calculating the average distance into the solution equation and establish the first formula, as shown below:

[0024]

[0025] Taking partial derivatives of the equations yields the following partial derivative matrix:

[0026]

[0027] Update coordinates using the following coordinate update formula. , , ):

[0028]

[0029] in, It is the iteration step size;

[0030] Update coordinates ( , , Substitute into the partial derivative matrix and determine , , , , If the value is less than the set value, the first formula is recalculated; if the number of calculations reaches the set number, all latitude and longitude coordinates of the second UAV are discarded, and the new latitude and longitude coordinates of the second UAV are stored; when the set value is met, the three-dimensional coordinates of coordinate D are obtained. , , );

[0031] Three-dimensional coordinates ( , , Substitute the values ​​into the following formula to perform a coordinate transformation and obtain the coordinates in the WGS-84 coordinate system. :

[0032]

[0033] Where, N is the radius of curvature of the ellipse. ;

[0034] Angle B is solved iteratively using the following method. ,when The iteration ends at that time.

[0035]

[0036] The latitude and longitude coordinates of the first UAV are obtained and displayed on the map, and the newly acquired data is recalculated.

[0037] On the other hand, the present invention also provides a drone locator system in the absence of network coverage, characterized in that it includes a data collection module and a drone locator module;

[0038] The data collection module is used to collect the network status and GNSS coordinate information of the UAV; when the first UAV is flying normally, the coordinate information collected by the GNSS module is sent to the server backend for storage through the communication module to obtain the GNSS coordinate points; when the first UAV crashes, the current network status and GNSS coordinate information of the first UAV are obtained.

[0039] The UAV search module is used to determine the current status of the UAV and specify the search method. If the first UAV is in a network state and its GNSS coordinate information is lost, the UWB module set on the first UAV is activated and the UAV waits for user control. Otherwise, the UAV crash point GNSS coordinate information is reported through the network and the UAV waits for user instructions.

[0040] Currently, when the first UAV is in a network-free state, it automatically activates the UWB module installed on its fuselage to search for a location. The second UAV is then used, and a base station is installed near the last GNSS coordinate point obtained during the UAV's normal flight. When the second UAV establishes a communication connection with the first UAV's UWB module, the base station obtains the communication feedback information from the second UAV in real time through the hardware and software interface. Based on the communication feedback information, the base station locates and searches for the first UAV to obtain its position information.

[0041] Preferably, the communication feedback information includes the RTK module information and UWB module information of the second UAV;

[0042] The RTK module information includes the real-time latitude, longitude, and altitude information of the second UAV; the UWB module information includes the latitude, longitude, altitude information of the second UAV, and the distance information between the second UAV and the first UAV when the second UAV is connected to the first UAV.

[0043] Preferably, the first drone is equipped with a first tag on its fuselage;

[0044] The second UAV fuselage includes: an RTK device and a second tag;

[0045] Both the first tag and the second tag include: a first communication module, a first UWB module, a buzzer module, a GNSS module, and a power module;

[0046] The base station hardware includes: a second communication module and a second UWB module;

[0047] Preferably, the first communication module is used to send the coordinate information collected by the GNSS module to the server backend for storage;

[0048] The GNSS module is used to receive and process signals from the Global Navigation Satellite System, and calculates the precise location and time information of the device through signal processing algorithms;

[0049] The RTK device utilizes real-time dynamic differential positioning technology to establish a radio link between the base station and the second UAV. The base station receives satellite signals and calculates differential data, which is then transmitted wirelessly to the second UAV. The second UAV uses the differential data to correct the GNSS signal.

[0050] In another aspect, the present invention also provides an electronic device having a computer program stored thereon, which, when executed by a processor, implements a method for locating drones in the absence of a network, as described in any embodiment of the present invention.

[0051] In another aspect, the present invention also provides a computer-readable medium for storing one or more programs, which, when executed by one or more processors, cause the one or more processors to implement a method for locating drones in the absence of a network, as described in any embodiment of the present invention.

[0052] The present invention has the following beneficial effects:

[0053] 1. This invention develops a novel drone locator hardware and applies a locator algorithm to enable another drone to locate a crashed drone in the absence of a network. Field verification has shown that this device can avoid the problem of drones being lost after crashing and improve the efficiency of on-site locator searches. Attached Figure Description

[0054] Figure 1 This is a schematic diagram of the process of the present invention. Detailed Implementation

[0055] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0056] It should be understood that the step numbers used in the text are for ease of description only and are not intended to limit the order in which the steps are performed.

[0057] It should be understood that the terminology used in this specification is for the purpose of describing particular embodiments only and is not intended to limit the invention. As used in this specification and the appended claims, the singular forms “a,” “an,” and “the” are intended to include the plural forms unless the context clearly indicates otherwise.

[0058] The terms “comprising” and “including” indicate the presence of the described feature, whole, step, operation, element and / or component, but do not exclude the presence or addition of one or more other features, wholes, steps, operations, elements, components and / or collections thereof.

[0059] The term “and / or” refers to any combination of one or more of the associated listed items, as well as all possible combinations, and includes these combinations.

[0060] Example 1:

[0061] This embodiment provides a method for locating drones in the absence of a network. Figure 1This is a flowchart illustrating a method for locating drones in the absence of a network, according to the present invention.

[0062] The specific steps of this method are as follows:

[0063] When the first UAV is flying normally, it sends the coordinate information collected by the GNSS module to the server backend for storage through the communication module, thus obtaining the GNSS coordinate points;

[0064] After the first UAV crashes, obtain the current network status and GNSS coordinate information of the first UAV.

[0065] The UAV search module is used to determine the current status of the UAV and specify the search method. If the first UAV is in a network state and its GNSS coordinate information is lost, the UWB module set on the first UAV is activated and the UAV waits for user control. Otherwise, the UAV crash point GNSS coordinate information is reported through the network and the UAV waits for user instructions.

[0066] Currently, when the first UAV is in a network-free state, it automatically activates the UWB module installed on its fuselage to search for a location. The second UAV is then used, and a base station is installed near the last GNSS coordinate point obtained during the UAV's normal flight. When the second UAV establishes a communication connection with the first UAV's UWB module, the base station obtains the communication feedback information from the second UAV in real time through the hardware and software interface. Based on the communication feedback information, the base station locates and searches for the first UAV to obtain its position information.

[0067] In a preferred embodiment of this invention, the UWB module is disabled by default during normal flight of the UAV. The 4G communication module (NB-IoT chip) collects the coordinate information acquired by the GNSS module and sends it to the server backend for storage. In the event of a crash, the communication module first determines whether there is still a 4G network signal. If the 4G network signal is lost, the UWB chip is activated to wait for other base stations to search. If the network signal is not lost and the GNSS coordinates are not lost, the GNSS data at the crash site is reported and user instructions are awaited. If the 4G signal exists but the GNSS coordinates are lost, the UWB module is activated by default to wait for the user to perform other controls.

[0068] In a preferred embodiment of this invention, after a drone crash, the user uses an RTK-enabled drone with a base station installed near the crash site and activates the UWB module to search for it. The base station acquires the drone's RTK information (latitude, longitude, and altitude) in real time through a hardware and software interface. When the search device connects to the crashed drone near the crash site via the UWB module, it stores the UWB distance information, the drone's latitude, longitude, and altitude information in real time. , Represents latitude and longitude. Represents height, The distance returned by UWB is represented by the following: ， ， The search algorithm was used to locate the crashed drone.

[0069] The algorithm for locating drones that have crashed without a network is as follows:

[0070] Step 1: Assume the Earth's semi-major axis α and oblateness f are 6378.137 km and 1 / 298.257223563 respectively. Then, consider the known points... ， ， The latitude and longitude are transformed using the following formula, assuming the coordinates of a point are... Convert it to The specific transformation formula is as follows:

[0071]

[0072] in, It is the eccentricity of the ellipsoid N is the radius of curvature of the ellipse. a represents the distance along the Earth's major axis; b represents the distance along the Earth's minor axis. , They are latitude and longitude, respectively; For height; The distance returned by UWB;

[0073] Step 2: Assume the coordinates of the coordinates of the object to be solved, D, are ( The equations to be solved are as follows:

[0074]

[0075] in, , , These are the coordinate values ​​of a point after the transformation in step one.

[0076] Step 3: Calculate the known points , , The average distance of the great circle from the unknown point D: Calculate the average value of the coordinates:

[0077]

[0078] Step 4: Substitute the average value obtained in Step 3 into the formula in Step 2 and establish the following formula:

[0079]

[0080] Taking the partial derivative of step two yields the following matrix:

[0081]

[0082] Step 5: Update the coordinates using the following formula ( , , ):

[0083]

[0084] in, It is the iteration step size; it can be adjusted as needed.

[0085] Step Six: Update the coordinates from Step Five ( , , Substitute into step four for inspection. , , , , Check if the error is less than 0.05. If not, return to step four to continue the calculation.

[0086] Step 7: If the error still does not meet the requirement of being less than 0.05 after 25 calculations, discard the known point coordinates and store the new ones. ， ， The coordinates of the unknown point D are returned to the beginning of the calculation. When the termination condition is met, the three-dimensional coordinates of the unknown point D are obtained. , , ).

[0087] Step 8: Take the (obtained in Step 7) , , Substitute the following formula to perform coordinate transformation, converting to WGS84: ;

[0088]

[0089] Where N is the same as in step one, and angle B is solved iteratively using the following method. ,when The iteration ends at that time.

[0090]

[0091] Step 9: Display the latitude and longitude coordinates obtained in Step 8 on the map, and add the newly acquired data to the calculations from the beginning of Step 8.

[0092] Example 2:

[0093] This embodiment provides a drone locator system in the absence of network connectivity, including a data collection module and a drone locator module;

[0094] The data collection module is used to collect the network status and GNSS coordinate information of the UAV; when the first UAV is flying normally, the coordinate information collected by the GNSS module is sent to the server backend for storage through the communication module to obtain the GNSS coordinate points; when the first UAV crashes, the current network status and GNSS coordinate information of the first UAV are obtained.

[0095] The UAV search module is used to determine the current status of the UAV and specify the search method. If the first UAV is in a network state and its GNSS coordinate information is lost, the UWB module set on the first UAV is activated and the UAV waits for user control. Otherwise, the UAV crash point GNSS coordinate information is reported through the network and the UAV waits for user instructions.

[0096] When the first drone is in a state without network, it automatically turns on the UWB module on its body to search for a location. The second drone is used and a base station is installed near the last GNSS coordinate point obtained during the normal flight of the first drone. When the second drone establishes a communication connection with the first drone's UWB module, the base station obtains the communication feedback information of the second drone in real time through the software and hardware interface, and locates the first drone based on the communication feedback information to obtain the location information of the first drone.

[0097] This embodiment is used to implement the function in Embodiment 1 above, and the details will not be repeated.

[0098] Example 3:

[0099] This embodiment provides an electronic device that stores a computer program, which, when executed by a processor, implements a method for locating drones in the absence of a network, as described in any embodiment of the present invention.

[0100] Example 4:

[0101] This embodiment provides a computer-readable medium for storing one or more programs, which, when executed by one or more processors, cause the one or more processors to implement a method for locating drones in the absence of a network, as described in any embodiment of the present invention.

[0102] In this application embodiment, "at least one" refers to one or more, and "more than one" refers to two or more. "And / or" describes the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent the existence of A alone, A and B simultaneously, or B alone. A and B can be singular or plural. The character " / " generally indicates that the preceding and following related objects are in an "or" relationship. "At least one of the following" and similar expressions refer to any combination of these items, including any combination of singular or plural items. For example, at least one of a, b, and c can represent: a, b, c, a and b, a and c, b and c, or a and b and c, where a, b, and c can be single or multiple.

[0103] Those skilled in the art will recognize that the units and algorithm steps described in the embodiments disclosed herein can be implemented using electronic hardware, computer software, or a combination of electronic hardware and software. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this application.

[0104] Those skilled in the art will understand that, for the sake of convenience and brevity, the specific working processes of the systems, devices, and units described above can be referred to the corresponding processes in the foregoing method embodiments, and will not be repeated here.

[0105] In the several embodiments provided in this application, any function, if implemented as a software functional unit and sold or used as an independent product, can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, or a part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of this application. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0106] The above description is merely an embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent structural or procedural transformations made based on the content of the present invention's specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of the present invention.

Claims

1. A method for locating drones in the absence of a network, characterized in that, Includes the following steps: When the first UAV is flying normally, it sends the coordinate information collected by the GNSS module to the server backend for storage through the communication module, thus obtaining the GNSS coordinate points; After the first UAV crashes, obtain the current network status and GNSS coordinate information of the first UAV. If the first UAV is currently connected to the network and its GNSS coordinates are lost, the UWB module installed on the first UAV will be activated and the UAV will wait for user control. Otherwise, the UAV will report the GNSS coordinates of the crash site via the network and wait for user instructions. Currently, the first drone is without network access. It automatically activates its UWB module to locate the first drone. A second drone, equipped with a base station, is positioned near the last GNSS coordinates obtained during normal flight. When the second drone establishes a communication connection with the first drone's UWB module, the base station receives real-time communication feedback from the second drone via hardware and software interfaces. Based on this feedback, the base station locates and determines the first drone's position. Specifically: Let the latitude and longitude coordinates of the second UAV be... The latitude and longitude coordinates of the second UAV are transformed to obtain the corresponding three-dimensional coordinates. The specific transformation formula is as follows: in, It is the eccentricity of the ellipsoid N is the radius of curvature of the ellipse. a represents the distance along the Earth's major axis; b represents the distance along the Earth's minor axis. , They are latitude and longitude, respectively; For height; The distance returned by the UWB module; Let the three-dimensional coordinates D of the first UAV be... The distance value returned by the UWB module is obtained by solving the equation. The specific solution to the equation is as follows: in, , , These are the values ​​of the three-dimensional coordinates converted from the latitude and longitude coordinates of the second UAV using a transformation formula; Calculate the three-dimensional coordinates corresponding to the i latitude and longitude coordinates of the second UAV. , , And calculate the average distance from the great circle to the three-dimensional coordinate D: Calculate the average distance between the i-th three-dimensional coordinates of the second UAV and the three-dimensional coordinates D of the first UAV. The formula for calculating the average distance is as follows: Substitute the formula for calculating the average distance into the solution equation and establish the first formula, as shown below: Taking partial derivatives of the equations yields the following partial derivative matrix: Update coordinates using the following coordinate update formula. , , ): in, It is the iteration step size; Update coordinates ( , , Substitute into the partial derivative matrix and determine , , , , If the value is less than the set value, the first formula is recalculated; if the number of calculations reaches the set number, all latitude and longitude coordinates of the second UAV are discarded, and the new latitude and longitude coordinates of the second UAV are stored; when the set value is met, the three-dimensional coordinates of coordinate D are obtained. , , ); Three-dimensional coordinates ( , , Substitute the values ​​into the following formula to perform a coordinate transformation and obtain the coordinates in the WGS-84 coordinate system. : Wherein, N is the radius of curvature of the ellipse. ; Angle B is solved iteratively using the following method. ,when The iteration ends at that time. The latitude and longitude coordinates of the first UAV are obtained and displayed on the map, and the newly acquired data is recalculated.

2. The method for locating drones in the absence of a network, as described in claim 1, is characterized in that: The communication feedback information includes the RTK module information and UWB module information of the second UAV; The RTK module information includes the real-time latitude, longitude, and altitude information of the second UAV; the UWB module information includes the latitude, longitude, altitude information of the second UAV, and the distance information between the second UAV and the first UAV when the second UAV is connected to the first UAV.

3. The method for locating drones in the absence of a network, as described in claim 2, is characterized in that: The first drone is equipped with a first tag on its fuselage; The second UAV fuselage includes: an RTK device and a second tag; Both the first tag and the second tag include: a first communication module, a first UWB module, a buzzer module, a GNSS module, and a power module; The base station hardware includes: a second communication module and a second UWB module.

4. The method for locating drones in the absence of a network, as described in claim 3, is characterized in that: The first communication module is used to send the coordinate information collected by the GNSS module to the server backend for storage; The GNSS module is used to receive and process signals from the Global Navigation Satellite System, and calculates the precise location and time information of the device through signal processing algorithms; The RTK device utilizes real-time dynamic differential positioning technology to establish a radio link between the base station and the second UAV. The base station receives satellite signals and calculates differential data, which is then transmitted wirelessly to the second UAV. The second UAV uses the differential data to correct the GNSS signal.

5. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, When the processor executes the program, it implements a method for locating drones in the absence of a network, as described in any one of claims 1 to 4.

6. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by the processor, it implements a method for locating unmanned aerial vehicles (UAVs) in the absence of a network, as described in any one of claims 1 to 4.

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