Dynamic positioning method and system based on unmanned aerial vehicle

Abstract

A dynamic positioning method and system based on an unmanned aerial vehicle. The method comprises: using the flight of an unmanned aerial vehicle to perform angle estimation, and using the flight of the unmanned aerial vehicle to observe a target multiple times under different attitude and position conditions, so as to determine the position of the target. In the present method, the characteristic of free flight of an unmanned aerial vehicle is used to construct a direct path between a positioning target and the unmanned aerial vehicle; and multi-dimensional information related to the position of a target is acquired by means of changing the attitude and position of the unmanned aerial vehicle, and a geometric relationship is used to perform solving, so as to obtain the position of the target.

Description

A dynamic positioning method and system based on unmanned aerial vehicles (UAVs) Technical Field

[0001] This invention relates to the field of wireless positioning technology, and in particular to a dynamic positioning method and system based on unmanned aerial vehicles (UAVs) in multi-target scenarios. Background Technology

[0002] With the popularization of drone technology, people have truly felt the unparalleled advantages of drones in transporting goods, conducting geographical surveys, and fire rescue. In future smart cities, drones, with their advantages of flexible configuration and low cost, will play an increasingly important role in traffic management and intelligent monitoring.

[0003] Location-based services are increasingly used in daily life, such as satellite navigation, automated parking, and unmanned logistics. The importance of location information is becoming increasingly prominent. However, high-precision positioning in complex scenarios such as urban canyons remains a challenge. Various wireless positioning technologies are emerging, including satellite navigation signal positioning, audio signal positioning, electromagnetic wave signal positioning, geomagnetic information positioning, and fusion positioning. Currently, most positioning methods use relatively fixed anchor points, ensuring positioning stability, but this also limits positioning flexibility to some extent. In obstructed areas, this method cannot achieve good positioning results. Summary of the Invention

[0004] Purpose of the Invention: To improve positioning accuracy and flexibility in complex scenarios such as urban canyons, this invention proposes a dynamic positioning method and system based on unmanned aerial vehicles (UAVs). This invention utilizes the free flight characteristics of UAVs to construct a direct path between the target and the UAV. By changing the attitude and position of the UAV, multi-dimensional information related to the target's position is obtained, and geometric relationships are used to solve for the target's location.

[0005] Technical solution: To achieve the above objectives, the present invention provides a dynamic positioning method based on unmanned aerial vehicles (UAVs), comprising the following steps:

[0006] Step 1: The UAV flies over the work area and hovers, providing location services for K targets. The UAV determines its current position based on satellite navigation signals and signals from ground communication base stations, denoted as Position 1. The tangent direction of the antenna array is determined based on its attitude and denoted as:

[0007] Step 2: The UAV transmits a location service broadcast signal. Upon receiving the broadcast signal, the ground target transmits a location service request. Upon receiving the target's location service request, the UAV transmits an access confirmation.

[0008] Step 3: The k-th user sends a positioning reference signal. The UAV uses this signal to estimate the angle of arrival (Angle of Arrival) of the user's antenna array to the UAV. When the UAV is equipped with a planar array antenna, the Angle of Arrival is denoted as... When the drone is equipped with a linear array antenna, the angle of arrival is denoted as θ. k,1 .

[0009] Step 4: The UAV changes its position or attitude, and the k-th user retransmits the positioning reference signal. The UAV uses the positioning reference signal to re-estimate the angle of arrival. When the UAV is equipped with a planar array antenna, the angle of arrival is denoted as... When the drone is equipped with a linear array antenna, the angle of arrival is denoted as θ. k,2 .

[0010] Step 5: Repeat step 4 until the number of angle measurements reaches the preset upper limit G.

[0011] Step 6: The UAV calculates the target's position based on its own coordinates, the tangent direction of the antenna array, multiple position or attitude information, and the corresponding estimated angle of arrival.

[0012] Optionally, the method for the ground base station to determine the location of the UAV is as follows: the ground base station determines the orientation of the UAV through image recognition, and then uses lidar to measure the distance between the UAV and the ground base station to determine the location of the UAV, and then fuses the results with the satellite positioning results.

[0013] Optionally, the method for the UAV to estimate the target's angle of arrival using the antenna array is as follows: the array antenna configured on the UAV can be a fully digital structure or a hybrid digital-analog structure. When it is a fully digital structure, estimation methods such as MUSIC and ESPRIT can be used to estimate the angle.

[0014] Optionally, the method by which the UAV calculates the target's position based on multiple of its own position / attitude information and the estimated angle of arrival at different positions / attitudes is as follows: Based on the UAV's position and attitude, calculate the coordinates of the UAV's antenna array in the global coordinate system. After the number of angle measurements reaches a preset upper limit, G sets of antenna array coordinates and corresponding angle of arrival information can be obtained. Based on the information in these G sets and a geometric positioning method, the target's position is calculated.

[0015] Optionally, K users may access the UAV network using an orthogonal time-division or orthogonal frequency-division multi-user access strategy.

[0016] The present invention also provides a system applying the above-described dynamic positioning method, comprising:

[0017] Unmanned aerial vehicle (UAV) module: Equipped with a satellite positioning module, a multi-antenna radio frequency unit, a laser communication module, and an attitude sensor;

[0018] Ground base station module: equipped with computer vision unit, laser ranging unit and high-speed laser communication interface;

[0019] Ground terminal module: Carries a wireless signal transmitter for establishing a communication link with the UAV;

[0020] The drone module, through multiple position / attitude adjustments and angle measurements, works in conjunction with the ground base station module to achieve precise target positioning.

[0021] The present invention also provides an electronic device, comprising: a memory and a processor; the memory is used to store computer-executable instructions, and the processor is used to execute the computer-executable instructions, wherein when the computer-executable instructions are executed by the processor, the steps of a dynamic positioning method based on an unmanned aerial vehicle are implemented.

[0022] The present invention also provides a computer-readable storage medium having stored thereon computer program instructions, which, when executed by a processor, implement the steps of a dynamic positioning method based on an unmanned aerial vehicle (UAV).

[0023] Beneficial effects: The beneficial effects of this invention are as follows:

[0024] 1) This invention proposes a new wireless positioning method that utilizes the flight characteristics of UAVs to extend fixed anchor points into mobile anchor points and construct a direct path between the target to be positioned and the UAV.

[0025] 2) In this invention, the UAV changes its attitude and position to acquire multi-dimensional information related to the target's location, and uses geometric relationships to solve for the target's position, improving positioning accuracy in complex situations such as urban canyons. By utilizing the dynamic flight of the UAV, a single UAV (access point) can locate the target, and by using multiple measurements, the positioning accuracy is improved. Attached Figure Description

[0026] Figure 1 is a flowchart of the dynamic positioning method based on UAV of the present invention;

[0027] Figure 2 shows the dynamic positioning scenario based on the UAV according to the present invention. Detailed Implementation

[0028] The present invention will be further explained below with reference to the embodiments and accompanying drawings.

[0029] Example 1

[0030] The scenario in this embodiment is shown in Figure 2. The UAV is equipped with a uniform linear array consisting of M antennas to locate ground targets in the work area. There are K targets in the work area, and the UAV locates K targets, with L antennas configured for each target.

[0031] This embodiment provides a dynamic positioning method based on unmanned aerial vehicles (UAVs), specifically including:

[0032] The drone flies over the work area and hovers, providing location services for K targets. The K targets are distinguished using orthogonal methods such as time-division or frequency-division. The drone determines its own position based on satellite navigation signals and signals from ground communication base stations. For a specific area, the drone changes its position or attitude a total of G times. For the g-th change, the global coordinates of the antenna array reference point on the drone are: And the unit vector corresponding to the tangent direction of the antenna array is denoted as

[0033] The drone transmits a location service broadcast signal. Upon receiving the broadcast signal, the ground target transmits a location service request. After receiving the target's location service request, the drone transmits an access confirmation. Taking the k-th user as an example, it sends a location reference signal s. k (n). The UAV uses a positioning reference signal to estimate the angle of arrival (AOA) of user k from the UAV's antenna array. When the UAV is in the g-th attitude or position, the estimated AOA of user k is denoted as θ. k,g Assume the coordinates of the kth user are... Define vector for:

[0034]

[0035] Therefore:

[0036]

[0037] Right now,

[0038]

[0039] Where <·,·> represents the inner product of two vectors, and ||·|| represents the magnitude of the vector.

[0040] Based on the results of G angle estimations, a system of G equations is established, from which the coordinates of the k-th user can be obtained.

[0041] Example 2

[0042] This embodiment provides a system applying the above-described dynamic positioning method, including:

[0043] 1. Unmanned Aerial Vehicle (UAV) Module:

[0044] Positioning module: Equipped with high-precision satellite positioning (GPS + Beidou), with an error of ≤5cm.

[0045] Sensors: Built-in gyroscope, accelerometer and magnetometer to monitor flight attitude in real time.

[0046] Communication unit: Equipped with a multi-antenna radio frequency module, used to search for ground terminal signals and determine direction.

[0047] Laser communication: Transmits data to ground base stations via lasers at speeds of 1Gbps or higher.

[0048] 2. Ground base station module:

[0049] Visual positioning: The camera identifies the drone's location, combined with laser ranging (accuracy ±1cm).

[0050] Control Center: Analyzes data and sends instructions to the drone (such as adjusting its flight path).

[0051] 3. Ground terminal module:

[0052] Device to be located: Carries a wireless signal transmitter (such as a Wi-Fi or UWB tag) for drone detection.

[0053] Example 3

[0054] This embodiment provides an electronic device, including: a memory and a processor; the memory is used to store computer-executable instructions, and the processor is used to execute the computer-executable instructions, wherein when the computer-executable instructions are executed by the processor, the steps of a dynamic positioning method based on a drone are implemented.

[0055] Processor: High-performance multi-core chip (such as ARM Cortex-A72) that supports fast computing.

[0056] Storage: Large-capacity hard drives store maps, sensor data, and positioning algorithms.

[0057] Communication interface: Supports Wi-Fi and 4G / 5G for connecting drones and base stations.

[0058] Example 4

[0059] This embodiment provides a computer-readable storage medium storing computer program instructions, which, when executed by a processor, implement the steps of a dynamic positioning method based on an unmanned aerial vehicle (UAV).

[0060] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0061] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "N" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0062] Any process or method description in the flowchart or otherwise herein can be understood as representing a module, segment, or portion of code comprising one or N executable instructions for implementing custom logic functions or processes, and the scope of preferred embodiments of the invention includes additional implementations in which functions may be performed not in the order shown or discussed, including substantially simultaneously or in reverse order depending on the functions involved, as will be understood by those skilled in the art to which embodiments of the invention pertain.

[0063] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A dynamic positioning method based on a drone, characterized in that, Includes the following steps: Step 1: The drone flies over the work area and hovers to provide location services to ground users; the drone determines its current position based on satellite navigation signals and signals from ground communication base stations, and determines the tangential direction of the antenna array based on its attitude; Step 2: The drone transmits a location service broadcast signal. After receiving the broadcast signal, the ground user transmits a location service request. After receiving the user's location service request, the drone transmits an access confirmation. Step 3: The ground user sends a positioning reference signal, and the UAV uses the positioning reference signal to estimate the angle of arrival of the UAV's antenna array from the ground user; Step 4: The drone changes its position or attitude, and the ground user sends the positioning reference signal again. The drone uses the positioning reference signal to re-estimate the angle of arrival. Step 5: Repeat step 4 until the number of angle measurements reaches the preset upper limit G; Step 6: The UAV calculates the target's position based on its own coordinates, the tangent direction of the antenna array, multiple position or attitude information, and the corresponding estimated angle of arrival.

2. The dynamic positioning method based on UAV according to claim 1, wherein, In step one, the method by which the UAV determines its current position based on satellite navigation signals and signals from ground communication base stations is as follows: the ground base station determines the UAV's orientation through image recognition, and then uses lidar to measure the distance between the UAV and the ground base station to determine the UAV's position, and then fuses the results with the satellite positioning.

3. The method of claim 1, wherein, In step three, the method for the UAV to estimate the target angle of arrival using the antenna array is as follows: the array antenna configured by the UAV is either a fully digital structure or a hybrid digital-analog structure; when it is a fully digital structure, the MUSIC or ESPRIT estimation method is used to estimate the angle.

4. The dynamic positioning method based on unmanned aerial vehicles as described in claim 1, characterized in that, In step six, the UAV calculates the target's position based on its own position / attitude information and the estimated angle of arrival under different positions / attitudes. The method is as follows: calculate the coordinates of the UAV antenna array in the global coordinate system based on the UAV's position and attitude; obtain G antenna array coordinates and corresponding angle of arrival information groups based on the number of angle measurements reaching the preset upper limit; and calculate the target's position based on the information of the G information groups and the geometric positioning method.

5. A dynamic positioning method based on an unmanned aerial vehicle (UAV) as described in claim 1, characterized in that, Ground users access the UAV network using orthogonal time division or orthogonal frequency division multi-user access strategies.

6. A system applying the dynamic positioning method according to any one of claims 1-5, characterized in that, include: Unmanned aerial vehicle (UAV) module: Equipped with a satellite positioning module, a multi-antenna radio frequency unit, a laser communication module, and an attitude sensor; Ground base station module: equipped with computer vision unit, laser ranging unit and high-speed laser communication interface; Ground terminal module: Carries a wireless signal transmitter for establishing a communication link with the UAV; The drone module, through multiple position / attitude adjustments and angle measurements, works in conjunction with the ground base station module to achieve precise target positioning.

7. An electronic device, comprising: Memory and processor; The memory is used to store computer-executable instructions, and the processor is used to execute the computer-executable instructions, which, when executed by the processor, implement the steps of the method according to any one of claims 1 to 5.

8. A computer-readable storage medium having stored thereon computer program instructions that, when executed by a processor, implement the steps of the method according to any one of claims 1 to 5.

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