Mooring unmanned aerial vehicle positioning system and method based on laser ranging

Abstract

The embodiment of the invention discloses a mooring unmanned aerial vehicle positioning system and method based on laser ranging. The system comprises a laser range finder, a visual tracking identification module and a data processing module, wherein the laser range finder is used for measuring distance data between at least three laser range finding points and the mooring unmanned aerial vehicle; wherein the at least three laser ranging points are three-dimensional laser ranging points, and the at least three laser ranging points are not collinear; the visual tracking identification module is used for tracking at least three laser ranging points on the ground in real time; and the data processing module is used for determining the three-dimensional position information of the mooring unmanned aerial vehicle according to the distance data between each laser ranging point and the mooring unmanned aerial vehicle. By adopting the scheme, high-precision positioning of the mooring unmanned aerial vehicle is realized by using a laser ranging technology without depending on global navigation satellite signals, and the mooring unmanned aerial vehicle can normally and stably work in an environment in which the global navigation satellite signals are interfered and shielded and urban canyons and forest coverage signals are unstable.

Description

Technical Field

[0001] The embodiments of the present invention relate to the technical field of unmanned aerial vehicle positioning, and in particular to a tethered unmanned aerial vehicle positioning system and method based on laser ranging. Background Art

[0002] In modern drone technology, positioning and navigation are key functions, especially in environments where global navigation satellite signals are limited or unavailable. Traditional drone positioning mainly relies on the global navigation satellite system.

[0003] However, in certain environments, such as urban canyons, forest cover or high-altitude indoor environments, GNSS signals may be interfered with or completely unavailable; and in military and security applications, GNSS signals may be interfered with or blocked, affecting the operation and positioning of drones.

[0004] Therefore, how to accurately locate the UAV is a technical problem that needs to be solved urgently by those skilled in the art. Summary of the invention

[0005] The embodiment of the present invention provides a tethered UAV positioning system and method based on laser ranging, so as to realize high-precision positioning of the tethered UAV without relying on global navigation satellite signals, and utilize laser ranging technology, and can work normally and stably in environments where global navigation satellite signals are interfered and shielded, urban canyons and forest cover environments where signals are unstable.

[0006] In a first aspect, an embodiment of the present invention provides a tethered drone positioning system based on laser ranging, the system comprising: a laser rangefinder, a visual tracking and recognition module, and a data processing module; wherein:

[0007] The laser rangefinder is used to measure the distance data between at least three laser ranging points and the tethered drone; wherein the at least three laser ranging points are three-dimensional laser ranging points, and the at least three laser ranging points are not collinear;

[0008] The visual tracking and recognition module is used to track at least three laser ranging points on the ground in real time;

[0009] The data processing module is used to determine the three-dimensional position information of the tethered drone based on the distance data between each laser ranging point and the tethered drone.

[0010] In a second aspect, an embodiment of the present invention further provides a tethered drone positioning method based on laser ranging, wherein the tethered drone positioning method based on laser ranging is applied to a tethered drone positioning system based on laser ranging, and the method comprises:

[0011] A laser rangefinder is used to respectively determine the distance data between at least three laser ranging points and the tethered drone; wherein the at least three laser ranging points are three-dimensional laser ranging points, and the at least three laser ranging points are not collinear;

[0012] Use the visual tracking and recognition module to track at least three laser ranging points on the ground in real time;

[0013] The data processing module is used to determine the three-dimensional position information of the tethered UAV based on the distance data between each laser ranging point and the tethered UAV.

[0014] The embodiment of the present invention provides a tethered drone positioning system and method based on laser ranging, the system includes a laser rangefinder, a visual tracking and identification module and a data processing module; wherein the laser rangefinder is used to measure the distance data between at least three laser ranging points and the tethered drone; wherein the at least three laser ranging points are three-dimensional laser ranging points, and the at least three laser ranging points are not collinear; the visual tracking and identification module is used to track at least three laser ranging points on the ground in real time; the data processing module is used to determine the three-dimensional position information of the tethered drone based on the distance data between each laser ranging point and the tethered drone. The technical solution of the embodiment of the present invention is adopted, which does not rely on global navigation satellite signals, but uses laser ranging technology to achieve high-precision positioning of tethered drones, and can work normally and stably in environments where global navigation satellite signals are interfered and shielded, urban canyons, forest coverage and other signal instability environments. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Other features, objects and advantages of the present invention will become more apparent by reading the detailed description of non-limiting embodiments made with reference to the following drawings. The drawings are only for the purpose of illustrating preferred embodiments and are not to be considered as limiting the present invention. Also, the same reference symbols are used throughout the drawings to represent the same parts. In the drawings:

[0016] Figure 1 is a structural schematic diagram of a tethered UAV positioning system based on laser ranging provided in an embodiment of the present invention;

[0017] Figure 2 It is a three-dimensional side view schematic diagram of positioning of a tethered UAV based on laser ranging provided in an embodiment of the present invention;

[0018] Figure 3 is a structural schematic diagram of another tethered UAV positioning system based on laser ranging provided in an embodiment of the present invention;

[0019] Figure 4 It is a two-dimensional top view schematic diagram of a tethered UAV positioning based on laser ranging provided in an embodiment of the present invention;

[0020] Figure 5 It is a flow chart of a tethered UAV positioning method based on laser ranging provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0021] The present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments. It is to be understood that the specific embodiments described herein are only used to explain the present invention, rather than to limit the present invention. It should also be noted that, for ease of description, only parts related to the present invention, rather than all structures, are shown in the accompanying drawings.

[0022] Before discussing the exemplary embodiments in more detail, it should be mentioned that some exemplary embodiments are described as processes or methods depicted as flow charts. Although the flow charts describe the operations (or steps) as sequential processes, many of the operations (or steps) therein can be implemented in parallel, concurrently or simultaneously. In addition, the order of the operations can be rearranged. The process can be terminated when its operation is completed, but can also have additional steps not included in the accompanying drawings. The process can correspond to a method, function, procedure, subroutine, subprogram, etc.

[0023] Among them, the acquisition, storage, use and processing of data in the technical solution of this application are in compliance with the relevant provisions of national laws and regulations. It should be noted that in the embodiments of this application, some existing solutions in the industry such as certain software, components or models may be mentioned, which should be considered as exemplary, and their purpose is only to illustrate the feasibility of the implementation of the technical solution of this application, but it does not mean that the applicant has or will necessarily use the solution.

[0024] It should be noted that the terms "first", "second", etc. in the specification and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the numbers used in this way can be interchanged where appropriate, so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein.

[0025] Embodiment 1

[0026] Figure 1 is a schematic diagram of the structure of a tethered UAV positioning system based on laser ranging provided in an embodiment of the present invention. This embodiment can be applied to the situation where a tethered UAV is positioned without relying on global navigation satellite signals, such as Figure 1 As shown, the tethered drone positioning system based on laser ranging provided in the embodiment of the present invention may include: a laser rangefinder 110, a visual tracking and recognition module 120 and a data processing module 130; wherein,

[0027] The laser rangefinder 110 is used to measure the distance data between at least three laser ranging points and the tethered drone; wherein the at least three laser ranging points are three-dimensional laser ranging points, and the at least three laser ranging points are not collinear;

[0028] The visual tracking and identification module 120 is used to track at least three laser ranging points on the ground in real time;

[0029] The data processing module 130 is used to determine the three-dimensional position information of the tethered drone based on the distance data between each laser ranging point and the tethered drone.

[0030] Among them, a tethered drone is a special type of drone whose key feature is the ability to stay in the air for a long time through a physical connection to the ground or other carriers, such as using a regular fishing line or a dedicated hardware tether. Tethered drones are usually equipped with a ground power station (also known as a drone station or tether station) that converts AC power into higher-power DC power and transmits it to the drone through the tether, allowing it to operate continuously without being limited by power.

[0031] The tethered drone in the embodiment of the present invention is equipped with a plurality of positioning auxiliary devices with adjusted optical axes, wherein the positioning auxiliary devices are formed by combining the laser rangefinder and a visual tracking and recognition module, and the laser ranging point is tracked by the visual tracking and recognition module.

[0032] Optionally, the laser ranging point is suitable for the current environment, using relatively high contrast to ensure bright colors for easy recognition by the visual tracking and recognition module; and the size of the laser ranging point should be large enough to ensure visibility within the flight altitude range of the tethered drone. Ensure that the laser ranging points are arranged in the tethered drone operating area, and the positions of these laser ranging points are accurately measured. The laser ranging point requires at least three known three-dimensional points, and a third three-dimensional point cannot appear on a straight line where two three-dimensional points are located, thereby ensuring that the triangle marked on the ground does not constitute a degenerate triangle, and then facilitating the calculation of the position of the tethered drone using triangulation.

[0033] In an optional solution of an embodiment of the present invention, the laser rangefinder has a compact and lightweight design and is equipped with a wireless communication module, and the measured distance data is transmitted to the data processing module in real time through the wireless communication module.

[0034] Optionally, the laser rangefinder is used to measure the distance between the laser ranging point and the tethered drone, and the laser rangefinder is equipped with a wireless communication module, which can transmit the measured distance data to the data processing module in real time. The laser rangefinder should have a compact and lightweight design to reduce the impact on the tethered drone.

[0035] In an optional solution of the embodiment of the present invention, the optical axis of the visual tracking and identification module is at the same point as the optical axis of the laser rangefinder, so as to accurately measure the distance data between at least three laser ranging points and the tethered drone.

[0036] Optionally, the visual tracking and recognition module is used to track the laser ranging point on the ground in real time, and by adjusting the optical axis of the laser ranging and the optical axis of the visual tracking and recognition module to the same point, the actual distance from the laser ranging point to the tethered drone can be accurately measured, and the visual tracking and recognition module should have a compact and lightweight design to reduce the impact on the aircraft.

[0037] In an optional solution of the embodiment of the present invention, the visual tracking and identification module is equipped with a high-resolution camera; the camera is integrated with image processing software to identify and track the laser ranging points.

[0038] The visual tracking and recognition module is equipped with a high-resolution camera to ensure that the ground laser ranging points can be covered. The visual tracking and recognition module integrates image processing software, and can use opencv and other software to identify and track laser ranging points. The processing includes image capture, feature detection, and continuous recognition, etc., to provide the laser rangefinder with real-time updated targets to ensure that the measured distance is more accurate.

[0039] Optionally, the laser rangefinder and the camera included in the visual tracking and recognition module can be set according to the number of laser ranging points to facilitate the measurement of the distance of each laser ranging point.

[0040] In an optional solution of an embodiment of the present invention, the data processing module is used to integrate the distance data between each laser ranging point and the tethered drone, and to combine the equations using the product of vector modules through triangulation to determine the three-dimensional position information of the tethered drone.

[0041] Among them, the data processing module is used to integrate and calculate the distance data collected by the laser rangefinder, integrate the distance data of three three-dimensional points or multiple three-dimensional points, and use the triangulation algorithm to combine the equations using the product of the vector modules to calculate the three-dimensional position information of the tethered drone. The triangulation method may refer to the use of one or more known reference points and measured angles to calculate the position of unknown points. The triangulation method is widely used in navigation, mapping, astronomy, and drone positioning. In the embodiment of the present invention, the data processing module uses triangulation to calculate the distance between each laser ranging point and the tethered drone, and obtains the actual position of the tethered drone through a series of operations.

[0042] In an optional solution of the embodiment of the present invention, see Figure 2, A, B, and C are laser ranging points, and the three-dimensional positions of the laser ranging points are known; M is the simulated position of the tethered drone, and different laser rangefinders are used to measure the distance of the three points. The positions of the three laser ranging points are: A (x1, y1, z1), B (x2, y2, z2), C (x3, y3, z3), and the simulated position of the tethered drone is M (x, y, z). The distance between the three laser ranging points can be expressed as:

[0043]

[0044] Among them, a BC Indicates the distance between laser ranging point B and laser ranging point C, b AC Indicates the distance between laser ranging point A and laser ranging point C, c AB Indicates the distance between laser ranging point A and laser ranging point B.

[0045] The distance between the three laser ranging points and the tethered drone can be expressed as:

[0046]

[0047] in, It represents the square of the distance from the laser ranging point A to the tethered drone. It represents the square of the distance between the laser ranging point B and the tethered drone. Represents the square of the distance from the laser ranging point C to the tethered drone.

[0048] By solving the above set of equations, the three-dimensional coordinate information of the tethered drone can be determined.

[0049] The embodiment of the present invention provides a tethered drone positioning system based on laser ranging, the system includes a laser rangefinder, a visual tracking and identification module and a data processing module; wherein the laser rangefinder is used to measure the distance data between at least three laser ranging points and the tethered drone; wherein the at least three laser ranging points are three-dimensional laser ranging points, and the at least three laser ranging points are not collinear; the visual tracking and identification module is used to track at least three laser ranging points on the ground in real time; the data processing module is used to determine the three-dimensional position information of the tethered drone based on the distance data between each laser ranging point and the tethered drone. The technical solution of the embodiment of the present invention is adopted, which does not rely on global navigation satellite signals, but uses laser ranging technology to achieve high-precision positioning of tethered drones, and can work normally and stably in environments where global navigation satellite signals are interfered and shielded, urban canyons, forest coverage and other signal instability environments.

[0050] Embodiment 2

[0051] The embodiment of the present invention further optimizes the above embodiment on the basis of the above embodiment, and the embodiment of the present invention can be combined with various optional solutions in one or more of the above embodiments. Figure 3 The tethered UAV positioning system based on laser ranging provided in the embodiment of the present invention further includes a ground control system 140; wherein,

[0052] The ground control system 140 is used to verify the three-dimensional position information of the tethered UAV based on the distance data measured by the laser rangefinder.

[0053] The ground control system verifies the three-dimensional position information of the tethered drone through the distance data fed back by the laser rangefinder to ensure the accuracy of the distance measured by the laser rangefinder. For example, the Z-axis data of at least three laser rangefinder points can be removed and the calculated three-dimensional position of the tethered drone can be verified using plane coordinates; if the error is small, it is ignored; if the error is large, the reverse is inferred to verify the correctness of the three-dimensional position of the tethered drone.

[0054] As an optional but non-limiting implementation, the ground control system is specifically used for:

[0055] Abstracting at least three laser ranging points and the tethered drone into a two-dimensional plane of a top view, and respectively determining the two-dimensional plane distances between the at least three laser ranging points and the tethered drone;

[0056] The two-dimensional position information of the tethered drone is determined according to the two-dimensional plane distance, and the three-dimensional position information of the tethered drone is verified according to the two-dimensional position information.

[0057] Among them, after determining the three-dimensional position information of the tethered drone, to further verify the accuracy of the tethered drone position, the three-dimensional position information of the tethered drone and the z-axis of at least three laser ranging points can be removed to abstract a two-dimensional plane of the top view; and further verification calculation is performed based on the calculated tethered drone position. The verification calculation is further verified by triangulation method, combined with the distance data returned by the laser rangefinder, to verify whether the distance from the tethered drone coordinates on the two-dimensional plane to each laser ranging point is accurate, and a slight error can be accepted.

[0058] As an optional but non-limiting implementation, the ground control system is further specifically used for:

[0059] The ground control system is used to display the real-time position information of the tethered UAV and provide path planning and navigation information to the tethered UAV based on the real-time position information; wherein the real-time position information includes three-dimensional position information and two-dimensional position information.

[0060] Among them, the tethered drone positioning system based on laser ranging in the embodiment of the present invention can realize the accurate positioning of the drone in a complex environment without relying on global navigation satellite signals for positioning, and can transmit the pre-measured tethered drone position back to the ground control system, and can display the real-time position of the tethered drone on the ground control system, and provide path planning and navigation. For example, the position of the tethered drone can be displayed based on the 3D position information of the tethered drone, and the position of the tethered drone can also be displayed in the ground control system based on the verified 2D position information.

[0061] In an optional solution of the embodiment of the present invention, see Figure 4 , is an abstract top view, where false positions 1, 2 and 3 are the false positions of the tethered drone calculated, and M is the real position of the aircraft. Every two laser ranging points on the ground combined with the tethered drone point can form a triangle system. The laser rangefinder detects the atmospheric pressure and can feedback the approximate height of the tethered drone; the real position of the tethered drone can be measured by triangulation. Among them, there can be two positions calculated by every two laser ranging points. Solving between the two laser ranging points can obtain the common position of the tethered drone, and the common position is the real position of the tethered drone.

[0062] An embodiment of the present invention provides a ground control system that verifies the three-dimensional position information of a tethered UAV to obtain more accurate position information; and can achieve accurate positioning of the UAV in a complex environment without relying on global navigation satellite signals for positioning, display the real-time position of the tethered UAV on the ground control system, and provide path planning and navigation.

[0063] Embodiment 3

[0064] Figure 5 The flowchart of a tethered drone positioning method based on laser ranging provided in an embodiment of the present invention is applicable to the situation where a tethered drone is positioned without relying on global navigation satellite signals. The method can be executed by a tethered drone positioning system based on laser ranging provided in any embodiment of the present invention. Figure 5 As shown, the tethered drone positioning method based on laser ranging provided in an embodiment of the present invention specifically includes the following steps:

[0065] S510: Use a laser rangefinder to respectively determine distance data between at least three laser ranging points and the tethered drone.

[0066] The at least three laser ranging points are three-dimensional laser ranging points, and the at least three laser ranging points are not collinear, thereby ensuring that the triangle marked on the ground does not constitute a degenerate triangle, thereby facilitating the calculation of the position of the tethered drone using triangulation.

[0067] As an optional but non-limiting implementation, the using of a laser rangefinder to respectively determine the distance data between at least three laser ranging points and the tethered drone includes:

[0068] A laser rangefinder is used to respectively determine the distance data between at least three laser ranging points and the tethered drone, and the measured distance data is transmitted to a data processing module in real time through a wireless communication module equipped with the laser rangefinder; wherein the laser rangefinder has a compact and lightweight design.

[0069] The laser rangefinder is used to measure the distance data between the laser ranging point and the tethered drone, and the laser rangefinder is equipped with a wireless communication module, which can transmit the measured distance data to the data processing module in real time. The laser rangefinder should have a compact and lightweight design to reduce the impact on the tethered drone.

[0070] S520: Use a visual tracking and recognition module to track at least three laser ranging points on the ground in real time.

[0071] The visual tracking and recognition module is used to track at least three laser ranging points on the ground in real time, and the optical axis of the laser ranging and the optical axis of the visual tracking and recognition module are adjusted to the same point to accurately measure the actual distance from the laser ranging point to the tethered drone. The visual tracking and recognition module should have a compact and lightweight design to reduce the impact on the aircraft.

[0072] S530, using a data processing module to determine the three-dimensional position information of the tethered drone based on the distance data between each laser ranging point and the tethered drone.

[0073] The data processing module is used to integrate and calculate the distance data collected by the laser rangefinder, and the distance data between the at least three laser ranging points and the tethered drone are integrated. The triangulation algorithm is used to combine the equations using the product of the vector modules to calculate the three-dimensional position information of the tethered drone.

[0074] As an optional but non-limiting implementation, the method further includes:

[0075] The ground control system is used to verify the three-dimensional position information of the tethered UAV based on the distance data measured by the laser rangefinder.

[0076] In the embodiment of the present invention, after determining the three-dimensional position information of the tethered drone, in order to further verify the accuracy of the position of the tethered drone, the three-dimensional position information of the tethered drone and the z-axis data of at least three laser ranging points can be removed to abstract a top-down view. Figure 23D plane; and further verification is performed based on the calculated position of the tethered drone.

[0077] The tethered drone positioning method based on laser ranging provided in the embodiments of the present invention can be applied to the tethered drone positioning system based on laser ranging provided in any of the above embodiments of the present invention, and has the corresponding functions and beneficial effects of the tethered drone positioning system based on laser ranging. For technical details not described in detail in the above embodiments, please refer to the tethered drone positioning system based on laser ranging provided in any of the embodiments of the present application.

[0078] It should be understood that the various forms of processes shown above can be used to reorder, add or delete steps. For example, the steps described in the present invention can be executed in parallel, sequentially or in different orders, as long as the desired results of the technical solution of the present invention can be achieved, and this document does not limit this.

[0079] The above specific implementations do not constitute a limitation on the protection scope of the present invention. It should be understood by those skilled in the art that various modifications, combinations, sub-combinations and substitutions can be made according to design requirements and other factors. Any modification, equivalent substitution and improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A tethered drone positioning system based on laser ranging, characterized in that: The system includes: a laser rangefinder, a visual tracking and recognition module and a data processing module; wherein, The laser rangefinder is used to measure the distance data between at least three laser ranging points and the tethered drone; wherein the at least three laser ranging points are three-dimensional laser ranging points, and the at least three laser ranging points are not collinear; The visual tracking and recognition module is used to track at least three laser ranging points on the ground in real time; The data processing module is used to determine the three-dimensional position information of the tethered drone based on the distance data between each laser ranging point and the tethered drone.

2. The system according to claim 1, characterized in that The laser rangefinder has a compact and lightweight design and is equipped with a wireless communication module, through which the measured distance data is transmitted to the data processing module in real time.

3. The system according to claim 1, characterized in that The optical axis of the visual tracking and identification module is at the same point as the optical axis of the laser rangefinder, so as to accurately measure the distance data between at least three laser ranging points and the tethered UAV.

4. The system according to claim 1, characterized in that The visual tracking and identification module is equipped with a high-resolution camera; the camera is integrated with image processing software to identify and track the laser ranging points.

5. The system according to claim 1, characterized in that The data processing module is used to integrate the distance data between each laser ranging point and the tethered drone, and to perform a combined equation group using the product of vector modules through triangulation to determine the three-dimensional position information of the tethered drone.

6. The system according to claim 1, characterized in that The system also includes a ground control system; wherein, The ground control system is used to verify the three-dimensional position information of the tethered UAV based on the distance data measured by the laser rangefinder.

7. The system according to claim 6, characterized in that The ground control system is specifically used for: Abstracting at least three laser ranging points and the tethered drone into a two-dimensional plane of a top view, and respectively determining the two-dimensional plane distances between the at least three laser ranging points and the tethered drone; The two-dimensional position information of the tethered drone is determined according to the two-dimensional plane distance, and the three-dimensional position information of the tethered drone is verified according to the two-dimensional position information.

8. The system according to claim 6, characterized in that The ground control system is also specifically used for: The ground control system is used to display the real-time position information of the tethered UAV and provide path planning and navigation information to the tethered UAV based on the real-time position information; wherein the real-time position information includes three-dimensional position information and two-dimensional position information.

9. A tethered drone positioning method based on laser ranging, characterized in that: The tethered UAV positioning method based on laser ranging is applied to a tethered UAV positioning system based on laser ranging, and the method comprises: A laser rangefinder is used to respectively determine the distance data between at least three laser ranging points and the tethered drone; wherein the at least three laser ranging points are three-dimensional laser ranging points, and the at least three laser ranging points are not collinear; Use the visual tracking and recognition module to track at least three laser ranging points on the ground in real time; The data processing module is used to determine the three-dimensional position information of the tethered UAV based on the distance data between each laser ranging point and the tethered UAV.

10. The method according to claim 9, characterized in that The method of using a laser rangefinder to respectively determine the distance data between at least three laser ranging points and the tethered drone includes: A laser rangefinder is used to respectively determine the distance data between at least three laser ranging points and the tethered drone, and the measured distance data is transmitted to a data processing module in real time through a wireless communication module equipped with the laser rangefinder; wherein the laser rangefinder has a compact and lightweight design.

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