UAV coordinate calibration method, system and medium based on three-dimensional coordinates

Abstract

The invention discloses a method, system and medium for calibrating coordinates of an unmanned aerial vehicle based on three-dimensional coordinates, and relates to the technical field of coordinate calibration of unmanned aerial vehicles, and comprises the following steps: obtaining the positioning of an unmanned aerial vehicle and the positioning of a nearby base station based on GPS positioning; calculating the distance between the unmanned aerial vehicle and the base station based on an initial positioning point and a base station positioning point, and marking it as a positioning distance; information interaction is performed between the unmanned aerial vehicle and the base station, and the distance between the unmanned aerial vehicle and the base station is calculated based on an interaction duration, and marked as an interaction distance; a three-dimensional coordinate system is established based on the position information of a flight control system of the unmanned aerial vehicle, and the three-dimensional coordinates of the unmanned aerial vehicle are calibrated by analyzing the positioning distance and the interaction distance; the invention is used to solve the problem that the existing unmanned aerial vehicle coordinate calibration technology still has poor applicability and insufficient calibration accuracy, resulting in large positioning calibration errors of the unmanned aerial vehicle.

Description

Technical Field

[0001] The present invention relates to the technical field of unmanned aerial vehicle coordinate calibration, and in particular to a method, system and medium for unmanned aerial vehicle coordinate calibration based on three-dimensional coordinates. Background Art

[0002] UAV coordinate calibration technology refers to the process and method of accurately calibrating the position and attitude of a UAV by using ground control points, sensor data or other reference information. The purpose of UAV coordinate calibration is to ensure that the UAV obtains accurate position and attitude information to support its various tasks and applications, such as track planning, navigation, and remote sensing data collection.

[0003] The existing UAV coordinate calibration technology usually calibrates the coordinates in the UAV's own flight control system in combination with a positioning system, and the existing UAV coordinate calibration technology uses image calibration combined with a positioning system for calibration. Image calibration involves selecting reference points or landmark buildings, but UAVs fly in different environments, and the standards of reference points or landmark buildings are difficult to unify. They are usually only applicable to UAVs flying in a fixed area. For example, in a patent application with application publication number CN117671543A, a radar target multi-feature matching and recognition method based on priority and weight is disclosed. This solution uses a combination of image calibration and a positioning system to calibrate the coordinates of the UAV. This solution requires calculating the vertex coordinates of the four vertices of the image taken by the UAV based on the actual height of the UAV and the GPS positioning coordinates of the UAV. This is difficult to achieve with existing technology, and the error is large, resulting in a large error in the positioning calibration of the UAV. The existing UAV coordinate calibration technology also has poor applicability and insufficient calibration accuracy, resulting in a large error in the positioning calibration of the UAV. Summary of the invention

[0004] The present invention aims to solve one of the technical problems in the prior art to at least a certain extent, by obtaining the positioning of a drone based on GPS positioning, marking it as an initial positioning point, and obtaining the positioning of a base station near the drone, marking it as a base station positioning point, and then calculating the distance between the drone and the base station based on the initial positioning point and the base station positioning point, marking it as a positioning distance, and then interacting information between the drone and the base station, recording the time between sending and receiving the information, marking it as an interaction time, and calculating the distance between the drone and the base station based on the interaction time, marking it as an interaction distance, establishing a three-dimensional positioning coordinate system based on the position information of the drone's flight control system, and marking the coordinates of the base station in the three-dimensional positioning coordinate system, analyzing and calculating the calibration points of the drone on the X-axis and the Y-axis, analyzing and calculating the calibration value of the drone on the Z-axis, and calibrating the three-dimensional coordinates of the drone in the flight control system, so as to solve the problem that the existing drone coordinate calibration technology still has poor applicability and insufficient calibration accuracy, resulting in large positioning calibration errors of the drone.

[0005] To achieve the above objectives, in a first aspect, the present application provides a method for calibrating drone coordinates based on three-dimensional coordinates, comprising the following steps:

[0006] Based on GPS positioning, the positioning of the drone is obtained and marked as the initial positioning point. At the same time, the positioning of the base station near the drone is obtained and marked as the base station positioning point.

[0007] The distance between the drone and the base station is calculated based on the initial positioning point and the base station positioning point, and marked as the positioning distance;

[0008] The drone exchanges information with the base station, records the time between sending and receiving information, and marks it as interaction time. The distance between the drone and the base station is calculated based on the interaction time, and marked as interaction distance.

[0009] A three-dimensional coordinate system is established based on the position information of the UAV's flight control system, and the three-dimensional coordinates of the UAV are calibrated by analyzing the positioning distance and the interaction distance.

[0010] Furthermore, obtaining the location of the drone based on GPS positioning, marking it as the initial positioning point, and obtaining the location of the base station near the drone includes the following sub-steps:

[0011] The location of the drone is obtained based on GPS positioning, which is marked as the initial positioning point. The initial positioning point is (lat0, lon0), where lat0 is the latitude of the initial positioning point and lon0 is the longitude of the initial positioning point.

[0012] Obtain the positions of the three base stations closest to the drone, which are marked as the first base station positioning point, the second base station positioning point, and the third base station positioning point, respectively. The first base station positioning point, the second base station positioning point, and the third base station positioning point are collectively referred to as base station positioning points;

[0013] The first base station positioning point includes (lat1, lon1), wherein lat1 is the latitude of the first base station positioning point, and lon1 is the longitude of the first base station positioning point; the second base station positioning point includes (lat2, lon2), wherein lat2 is the latitude of the second base station positioning point, and lon2 is the longitude of the second base station positioning point; the third base station positioning point includes (lat3, lon3), wherein lat3 is the latitude of the third base station positioning point, and lon3 is the longitude of the third base station positioning point.

[0014] Furthermore, the distance between the UAV and the base station is calculated based on the initial positioning point and the base station positioning point, which is marked as the positioning distance and includes the following sub-steps:

[0015] Calculate the positioning distance between the drone and the base station using the distance calculation formula;

[0016] The distance calculation formula is configured as:

[0017]

[0018]

[0019] ;

[0020] Among them, lat n is lat1, lat2 or lat3, lon n is lon1, lon2 or lon3, atan2 is the inverse tangent function, R is the radius of the earth, D n is the positioning distance, b is the intermediate variable, and c is the arc difference between the initial positioning point and the base station positioning point;

[0021] The positioning distance includes a first positioning distance D1, a second positioning distance D2 and a third positioning distance D3.

[0022] Furthermore, the UAV and the base station perform information exchange, record the time between information sending and receiving, and mark it as interaction time. Calculate the distance between the UAV and the base station based on the interaction time, and mark it as interaction distance, including the following sub-steps:

[0023] The drone exchanges information with the base station, and the time between sending and receiving the information is recorded, which is marked as the interaction time. The interaction time includes the first interaction time, the second interaction time and the third interaction time, which correspond to the three base stations respectively.

[0024] Obtain a radio wave propagation speed, multiply the radio wave propagation speed by the first interaction duration, and then divide by 2 to obtain a first interaction distance;

[0025] Multiply the radio wave propagation speed by the second interaction duration and divide by 2 to obtain the second interaction distance;

[0026] Multiply the radio wave propagation speed by the third interaction duration and divide by 2 to obtain the third interaction distance.

[0027] Furthermore, establishing a three-dimensional coordinate system based on the position information of the flight control system of the UAV and calibrating the three-dimensional coordinates of the UAV by analyzing the positioning distance and the interaction distance includes the following sub-steps:

[0028] A three-dimensional positioning coordinate system is established based on the position information of the flight control system of the UAV, and the coordinates of the base station are marked in the three-dimensional positioning coordinate system;

[0029] Analyze and calculate the calibration points of the drone on the X-axis and Y-axis;

[0030] Analyze and calculate the calibration value of the UAV on the Z axis, and calibrate the three-dimensional coordinates of the UAV in the flight control system.

[0031] Furthermore, establishing a three-dimensional positioning coordinate system based on the position information of the flight control system of the UAV and marking the coordinates of the base station in the three-dimensional positioning coordinate system includes the following sub-steps:

[0032] A three-dimensional coordinate system is established with the position of the UAV's flight control system as the origin, the east as the X axis, the north as the Y axis, and the vertical upward as the Z axis, and is named the three-dimensional positioning coordinate system;

[0033] Get the coordinates of the drone in the three-dimensional positioning coordinate system and name them as the coordinates to be calibrated;

[0034] The positioning of the flight control system is obtained through GPS, which is marked as the system positioning. The distances between the system positioning and the first base station positioning, the second base station positioning, and the third base station positioning are calculated through the distance calculation formula, which are marked as the first coordinate distance, the second coordinate distance, and the third coordinate distance respectively;

[0035] Based on the first coordinate distance, the second coordinate distance and the third coordinate distance, the base stations are marked in the three-dimensional positioning coordinate system, wherein the base stations include base station No. 1, base station No. 2 and base station No. 3, and the angle of the base station relative to the flight control system can be obtained by GPS positioning;

[0036] The coordinates of base station number 1, base station number 2, and base station number 3 are obtained and marked as coordinate number 1, coordinate number 2, and coordinate number 3 respectively.

[0037] Furthermore, analyzing and calculating the calibration points of the drone on the X-axis and the Y-axis includes the following sub-steps:

[0038] Calculate the average value of the first positioning distance and the first interaction distance, and name the calculation result as the first average distance; calculate the average value of the second positioning distance and the second interaction distance, and name the calculation result as the second average distance; calculate the average value of the third positioning distance and the third interaction distance, and name the calculation result as the third average distance;

[0039] Taking coordinate No. 1 as an endpoint, draw a straight line to the coordinate to be calibrated, named as straight line No. 1, the length of straight line No. 1 is the first average distance, and the other endpoint of straight line No. 1 is named as endpoint No. 1;

[0040] Taking the second coordinate as an endpoint, draw a straight line to the coordinate to be calibrated, named as the second straight line, the length of the second straight line is the second average distance, and the other endpoint of the second straight line is named as the second endpoint;

[0041] Taking the third coordinate as an endpoint, a straight line is drawn to the coordinate to be calibrated, and the straight line is named as the third straight line. The length of the third straight line is the third average distance, and the other endpoint of the third straight line is named as the third endpoint.

[0042] Connect endpoints 1, 2, and 3 to obtain a triangle named a calibration triangle, and mark the coordinates of the geometric center of the calibration triangle as an XY calibration point.

[0043] Furthermore, analyzing and calculating the calibration value of the drone on the Z axis and calibrating the three-dimensional coordinates of the drone in the flight control system includes the following sub-steps:

[0044] The incident angle of the return signal of the UAV is obtained through the flight control system, which is named as the signal incident angle. The signal incident angle is the angle between the return signal and the horizontal ground;

[0045] Get the X coordinate and Y coordinate of the XY calibration point, and mark them as X-axis calibration value and Y-axis calibration value respectively;

[0046] Calculate the Z-axis calibration value of the coordinate to be calibrated by using the Z-axis calibration formula;

[0047] The Z-axis calibration formula is configured as: , where JZ is the Z-axis calibration value, JX is the X-axis calibration value, JY is the Y-axis calibration value, and θ is the signal incident angle;

[0048] Get the X, Y and Z of the coordinates to be calibrated, and name them as X value to be calibrated, Y value to be calibrated and Z value to be calibrated respectively;

[0049] Calculate the X-axis calibration value minus the X value to be calibrated to obtain the X calibration value; calculate the Y-axis calibration value minus the Y value to be calibrated to obtain the Y calibration value; calculate the Z-axis calibration value minus the Z value to be calibrated to obtain the Z calibration value;

[0050] Calibrate each acquired coordinate of the drone in the three-dimensional positioning coordinate system, increase X by the X calibration value, increase Y by the Y calibration value, and increase Z by the Z calibration value.

[0051] In a second aspect, the present application provides a drone coordinate calibration system based on three-dimensional coordinates, including a GPS positioning module, a positioning distance calculation module, an interactive distance calculation module and a three-dimensional coordinate calibration module; the GPS positioning module, the positioning distance calculation module and the interactive distance calculation module are respectively connected to the three-dimensional coordinate calibration module data;

[0052] The GPS positioning module is used to obtain the location of the UAV based on GPS positioning, marked as the initial positioning point, and simultaneously obtain the location of the base station near the UAV, marked as the base station positioning point;

[0053] The positioning distance calculation module is used to calculate the distance between the UAV and the base station based on the initial positioning point and the base station positioning point, which is marked as the positioning distance;

[0054] The interaction distance calculation module is used to interact with the base station through the drone, record the time between sending and receiving the information, marked as the interaction time, and calculate the distance between the drone and the base station based on the interaction time, marked as the interaction distance;

[0055] The three-dimensional coordinate calibration module is used to establish a three-dimensional coordinate system based on the position information of the flight control system of the UAV, and calibrate the three-dimensional coordinates of the UAV by analyzing the positioning distance and the interaction distance.

[0056] In a third aspect, the present application provides a storage medium having a computer program stored thereon, and when the computer program is executed by a processor, the steps in the above method are performed.

[0057] Beneficial effects of the present invention: The present invention locates the drone and the base station near the drone based on GPS positioning, and then calculates the positioning distance between them. The advantage is that the positioning system is used to calibrate the coordinates of the drone, and the base station is used as a reference point to calibrate the drone. The base stations are distributed in every city and can exchange information with the drone, which greatly improves the accuracy and effectiveness of the drone coordinate calibration;

[0058] The present invention uses a drone to exchange information with a base station, records the time between information sending and receiving, marks it as interaction time, and calculates the interaction distance between the drone and the base station based on the interaction time. The advantage is that the main body uses a positioning system to calibrate the coordinates of the drone, and at the same time, the coordinate calibration of the drone is assisted by the information interaction between the drone and the base station. The drone and the base station interact through electromagnetic waves, and the interaction distance between them can be obtained through the interaction time and the propagation speed of the electromagnetic waves, which further improves the accuracy and effectiveness of the drone coordinate calibration.

[0059] The present invention establishes a three-dimensional positioning coordinate system based on the position information of the flight control system of the unmanned aerial vehicle, and at the same time marks the coordinates of the base station in the three-dimensional positioning coordinate system, analyzes and calculates the calibration points of the unmanned aerial vehicle on the X-axis and the Y-axis, analyzes and calculates the calibration value of the unmanned aerial vehicle on the Z-axis, and calibrates the three-dimensional coordinates of the unmanned aerial vehicle in the flight control system. The advantage of the present invention is that the XY coordinates of the unmanned aerial vehicle are calibrated by combining the positioning system with information interaction, and the Z coordinate is calibrated based on the incident angle of the signal, thereby improving the accuracy of the unmanned aerial vehicle coordinate calibration. BRIEF DESCRIPTION OF THE DRAWINGS

[0060] Figure 1 is a functional block diagram of the system of the present invention;

[0061] Figure 2 is the three-dimensional positioning coordinate system of the present invention;

[0062] Figure 3 is a schematic diagram of a base station in a three-dimensional positioning coordinate system of the present invention;

[0063] Figure 4 A top view of the three-dimensional positioning coordinate system of the present invention;

[0064] Figure 5 is a schematic diagram of a calibration triangle of the present invention;

[0065] Figure 6 The figure is a flow chart of the steps of the method of the present invention. DETAILED DESCRIPTION

[0066] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0067] Example 1, please refer to Figure 1As shown, in the first aspect, the present application provides a UAV coordinate calibration system based on three-dimensional coordinates, including a GPS positioning module, a positioning distance calculation module, an interactive distance calculation module and a three-dimensional coordinate calibration module; the GPS positioning module, the positioning distance calculation module and the interactive distance calculation module are respectively connected to the three-dimensional coordinate calibration module data;

[0068] The GPS positioning module is used to obtain the location of the drone based on GPS positioning, marked as the initial positioning point, and to obtain the location of the base station near the drone, marked as the base station positioning point;

[0069] The GPS positioning module is configured with a GPS positioning strategy, which includes:

[0070] The location of the drone is obtained based on GPS positioning, which is marked as the initial positioning point. The initial positioning point is (lat0, lon0), where lat0 is the latitude of the initial positioning point and lon0 is the longitude of the initial positioning point.

[0071] Obtain the positions of the three base stations closest to the drone, which are marked as the first base station positioning point, the second base station positioning point, and the third base station positioning point, respectively. The first base station positioning point, the second base station positioning point, and the third base station positioning point are collectively referred to as base station positioning points;

[0072] The first base station positioning point includes (lat1, lon1), where lat1 is the latitude of the first base station positioning point, and lon1 is the longitude of the first base station positioning point; the second base station positioning point includes (lat2, lon2), where lat2 is the latitude of the second base station positioning point, and lon2 is the longitude of the second base station positioning point; the third base station positioning point includes (lat3, lon3), where lat3 is the latitude of the third base station positioning point, and lon3 is the longitude of the third base station positioning point;

[0073] In practical applications, GPS positioning is implemented using the existing GPS positioning system, and the initial positioning point is (31.807633863497934, 117.4097728729248), where lat0 is 31.807633863497934 and lon0 is 117.4097728729248; the first base station positioning point is (31.822585527131874,117.35870361328125), the second base station positioning point is (31.815438204557204, 117.45569229125977), and the third base station positioning point is (31.771667028016626, 117.43878364562988).

[0074] The positioning distance calculation module is used to calculate the distance between the drone and the base station based on the initial positioning point and the base station positioning point, which is marked as the positioning distance;

[0075] The positioning distance calculation module is configured with a positioning distance calculation strategy, which includes:

[0076] Calculate the positioning distance between the drone and the base station using the distance calculation formula;

[0077] The distance calculation formula is configured as:

[0078]

[0079]

[0080] ;

[0081] Among them, lat n is lat1, lat2 or lat3, lon n is lon1, lon2 or lon3, atan2 is the inverse tangent function, R is the radius of the earth, D n is the positioning distance, b is the intermediate variable, and c is the arc difference between the initial positioning point and the base station positioning point;

[0082] The positioning distance includes a first positioning distance D1, a second positioning distance D2 and a third positioning distance D3;

[0083] In practical applications, the radius R of the earth is usually 6371 km. By calculation, the first positioning distance D1 is 5103.83 m, the second positioning distance D2 is 4424.95 m, and the third positioning distance D3 is 4849.01 m.

[0084] The interaction distance calculation module is used to exchange information between the drone and the base station, record the time between sending and receiving information, marked as the interaction time, and calculate the distance between the drone and the base station based on the interaction time, marked as the interaction distance;

[0085] The interactive distance calculation module is configured with an interactive distance calculation strategy, which includes:

[0086] The drone exchanges information with the base station, and the time between sending and receiving the information is recorded, which is marked as the interaction time. The interaction time includes the first interaction time, the second interaction time, and the third interaction time, which correspond to the three base stations respectively.

[0087] Obtain a radio wave propagation speed, multiply the radio wave propagation speed by the first interaction duration, and then divide by 2 to obtain a first interaction distance;

[0088] Multiply the radio wave propagation speed by the second interaction duration and divide by 2 to obtain the second interaction distance;

[0089] Multiply the radio wave propagation speed by the third interaction duration and divide by 2 to obtain the third interaction distance;

[0090] In practical applications, the purpose of information interaction is to calculate the distance between the drone and the base station based on the propagation speed of electromagnetic waves in the air, and to assist the GPS system in calibrating the coordinates of the drone. Through interaction, the first interaction duration is 51.0438㎲, which is 0.0000510438s when converted to seconds, the second interaction duration is 44.2505㎲, which is 0.0000442505s when converted to seconds, and the third interaction duration is 48.4875㎲, which is 0.0000484875s when converted to seconds. The radio wave propagation speed is 2×10 8 m / s. The calculation results show that the first interaction distance is 5104.38m, the second interaction distance is 4425.05m, and the third interaction distance is 4848.75m.

[0091] The three-dimensional coordinate calibration module is used to establish a three-dimensional coordinate system based on the position information of the UAV's flight control system, and calibrate the three-dimensional coordinates of the UAV by analyzing the positioning distance and the interaction distance; the three-dimensional coordinate calibration module includes a coordinate system construction unit, an XY axis calibration unit, and a Z axis calibration unit;

[0092] The coordinate system construction unit is configured with a coordinate system construction strategy, which includes:

[0093] See also Figure 2 As shown, a three-dimensional coordinate system is established with the position of the UAV's flight control system as the origin, the east as the X axis, the north as the Y axis, and the vertical upward as the Z axis, which is named the three-dimensional positioning coordinate system;

[0094] Get the coordinates of the drone in the three-dimensional positioning coordinate system and name them as the coordinates to be calibrated;

[0095] The positioning of the flight control system is obtained through GPS, which is marked as the system positioning. The distances between the system positioning and the first base station positioning, the second base station positioning, and the third base station positioning are calculated through the distance calculation formula, which are marked as the first coordinate distance, the second coordinate distance, and the third coordinate distance respectively;

[0096] In practical applications, the construction of the three-dimensional positioning coordinate system is as follows: Figure 2As shown in the figure, the X axis is due east and the Y axis is due north. Before each flight, the coordinates of the drone are calibrated by hovering in the air. After the calibration is completed, each coordinate in this flight is calibrated using the calibration parameters of this time; the coordinates to be calibrated are obtained as (0,7,10), and the system positioning is obtained as (31.807564836012173,117.4097728729248). The distance calculation formula is used to calculate the first coordinate distance to be 5106.34m, the second coordinate distance to be 4426.46m, and the third coordinate distance to be 4842.68m.

[0097] See also Figure 3 As shown, the base station is marked in the three-dimensional positioning coordinate system based on the first coordinate distance, the second coordinate distance and the third coordinate distance, the base station includes base station No. 1, base station No. 2 and base station No. 3, and the angle of the base station relative to the flight control system can be obtained by GPS positioning;

[0098] Obtain the coordinates of base station No. 1, base station No. 2, and base station No. 3, and mark them as coordinate No. 1, coordinate No. 2, and coordinate No. 3 respectively;

[0099] In practical applications, the angle of the base station relative to the flight control system is the azimuth, which is the horizontal angle from the north direction line of a certain point to the target direction line in a clockwise direction. The azimuths of base stations No. 1, No. 2 and No. 3 relative to the flight control system obtained by the GPS system are 289.1°, 78.6° and 145.5° respectively. Based on the first coordinate distance, the second coordinate distance, the third coordinate distance and the azimuth, the base stations are marked in the three-dimensional positioning coordinate system as follows: Figure 3 As shown, the coordinates of number one are (-4825.23, 1670.89, 0), the coordinates of number two are (4339.13, 874.92, 0), and the coordinates of number three are (2742.92, -3990.98, 0);

[0100] The XY-axis calibration unit is configured with an XY-axis calibration strategy, which includes:

[0101] Calculate the average value of the first positioning distance and the first interaction distance, and name the calculation result as the first average distance; calculate the average value of the second positioning distance and the second interaction distance, and name the calculation result as the second average distance; calculate the average value of the third positioning distance and the third interaction distance, and name the calculation result as the third average distance;

[0102] In practical applications, there will be large errors in calibrating the coordinates of the drone using the GPS positioning system or the propagation of electromagnetic waves alone. In order to reduce the error, the two are combined to find the average value to be closer to the actual distance. The first average distance is 5104.11m, the second average distance is 4425m, and the third average distance is 4848.88m. The calculation results are all retained to two decimal places.

[0103] See also Figure 4 As shown, with coordinate No. 1 as the endpoint, a straight line is drawn to the coordinate to be calibrated, named as straight line No. 1, the length of straight line No. 1 is the first average distance, and the other endpoint of straight line No. 1 is named as endpoint No. 1;

[0104] With the No. 2 coordinate as the endpoint, draw a straight line to the coordinate to be calibrated, named as the No. 2 straight line, the length of the No. 2 straight line is the second average distance, and the other endpoint of the No. 2 straight line is named as the No. 2 endpoint;

[0105] With the third coordinate as the endpoint, draw a straight line to the coordinate to be calibrated, named as the third straight line, the length of the third straight line is the third average distance, and the other endpoint of the third straight line is named as the third endpoint;

[0106] See also Figure 5 As shown, endpoints 1, 2, and 3 are connected, and the resulting triangle is named a calibration triangle, and the coordinates of the geometric center of the calibration triangle are marked as an XY calibration point;

[0107] In practical applications, since only the XY axis of the drone is calibrated at present, for the convenience of observation, a top view of the three-dimensional positioning coordinate system is used for demonstration; the first straight line, the second straight line, and the third straight line are drawn as follows Figure 4 As shown, Figure 4 That is, the top view of the three-dimensional positioning coordinate system; Figure 5 This is a schematic diagram of the calibration triangle. The XY calibration point is (0.39, 7.45). Since only the X-axis and Y-axis are considered, the Z-axis is omitted.

[0108] The Z-axis calibration unit is configured with a Z-axis calibration strategy, which includes:

[0109] The incident angle of the return signal of the UAV is obtained through the flight control system, which is named the signal incident angle. The signal incident angle is the angle between the return signal and the horizontal ground;

[0110] Get the X coordinate and Y coordinate of the XY calibration point, and mark them as X-axis calibration value and Y-axis calibration value respectively;

[0111] Calculate the Z-axis calibration value of the coordinate to be calibrated by using the Z-axis calibration formula;

[0112] The Z-axis calibration formula is configured as: , where JZ is the Z-axis calibration value, JX is the X-axis calibration value, JY is the Y-axis calibration value, and θ is the signal incident angle;

[0113] Get the X, Y and Z of the coordinates to be calibrated, and name them as X value to be calibrated, Y value to be calibrated and Z value to be calibrated respectively;

[0114] Calculate the X-axis calibration value minus the X value to be calibrated to obtain the X calibration value; calculate the Y-axis calibration value minus the Y value to be calibrated to obtain the Y calibration value; calculate the Z-axis calibration value minus the Z value to be calibrated to obtain the Z calibration value;

[0115] Calibrate each acquired coordinate of the drone in the three-dimensional positioning coordinate system, increase X by the X calibration value, increase Y by the Y calibration value, and increase Z by the Z calibration value;

[0116] In practical applications, the signal incident angle is 54.8°, the X-axis calibration value JX=0.39, the Y-axis calibration value JY=7.45, and θ=54.8°. The Z-axis calibration value JZ=10.58 is calculated, and the coordinates to be calibrated are (0,7,10), that is, the X value to be calibrated is 0, the Y value to be calibrated is 7, and the Z value to be calibrated is 10. The calculated X calibration value is 0.39, the Y calibration value is 0.45, and the Z calibration value is 0.58. Each time the three-dimensional positioning of the drone is obtained, for example, the coordinates of the drone currently obtained by the flight control system are (12.38, 16.54, 24.88), and the coordinates obtained by calibration are (12.38+0.39, 16.54+0.45, 24.88+0.58), that is, (12.77, 16.99, 25.46).

[0117] Example 2, please refer to Figure 6 As shown, in the second aspect, the present application provides a method for calibrating drone coordinates based on three-dimensional coordinates, comprising the following steps:

[0118] Step S1, based on GPS positioning, obtain the location of the drone, mark it as the initial positioning point, and simultaneously obtain the location of the base station near the drone, mark it as the base station positioning point; Step S1 includes the following sub-steps:

[0119] Step S101, obtaining the location of the drone based on GPS positioning, marked as an initial positioning point, the initial positioning point is (lat0, lon0), where lat0 is the latitude of the initial positioning point, and lon0 is the longitude of the initial positioning point;

[0120] Step S102, obtaining the positions of the three base stations closest to the drone, which are marked as the first base station positioning point, the second base station positioning point and the third base station positioning point, respectively. The first base station positioning point, the second base station positioning point and the third base station positioning point are collectively referred to as base station positioning points;

[0121] Step S103, the first base station positioning point includes (lat1, lon1), where lat1 is the latitude of the first base station positioning point, and lon1 is the longitude of the first base station positioning point; the second base station positioning point includes (lat2, lon2), where lat2 is the latitude of the second base station positioning point, and lon2 is the longitude of the second base station positioning point; the third base station positioning point includes (lat3, lon3), where lat3 is the latitude of the third base station positioning point, and lon3 is the longitude of the third base station positioning point;

[0122] Step S2, based on the initial positioning point and the base station positioning point, calculate the distance between the drone and the base station, marked as the positioning distance; Step S2 includes the following sub-steps:

[0123] Step S201, calculating the positioning distance between the drone and the base station using a distance calculation formula;

[0124] The distance calculation formula is configured as:

[0125]

[0126]

[0127] ;

[0128] Among them, lat n is lat1, lat2 or lat3, lon n is lon1, lon2 or lon3, atan2 is the inverse tangent function, R is the radius of the earth, D n is the positioning distance, b is the intermediate variable, and c is the arc difference between the initial positioning point and the base station positioning point;

[0129] Step S202, the positioning distance includes a first positioning distance D1, a second positioning distance D2 and a third positioning distance D3;

[0130] Step S3, the drone exchanges information with the base station, records the time between sending and receiving the information, marks it as the interaction time, and calculates the distance between the drone and the base station based on the interaction time, marks it as the interaction distance; Step S3 includes the following sub-steps:

[0131] Step S301, the drone exchanges information with the base station, and the time between sending and receiving the information is recorded, which is marked as interaction time. The interaction time includes a first interaction time, a second interaction time, and a third interaction time, which correspond to three base stations respectively.

[0132] Step S302, obtaining a radio wave propagation speed, multiplying the radio wave propagation speed by the first interaction duration and then dividing by 2 to obtain a first interaction distance;

[0133] Step S303, multiplying the radio wave propagation speed by the second interaction duration and then dividing by 2 to obtain a second interaction distance;

[0134] Step S304, multiplying the radio wave propagation speed by the third interaction duration and then dividing by 2 to obtain a third interaction distance;

[0135] Step S4, establishing a three-dimensional coordinate system based on the position information of the flight control system of the UAV, and calibrating the three-dimensional coordinates of the UAV by analyzing the positioning distance and the interaction distance; Step S4 includes the following sub-steps:

[0136] Step S401, establishing a three-dimensional positioning coordinate system based on the position information of the flight control system of the UAV, and marking the coordinates of the base station in the three-dimensional positioning coordinate system;

[0137] Step S401 includes the following sub-steps:

[0138] Step S4011, establish a three-dimensional coordinate system with the position of the flight control system of the UAV as the origin, eastward as the X axis, northward as the Y axis, and vertically upward as the Z axis, and name it the three-dimensional positioning coordinate system;

[0139] Step S4012, obtaining the coordinates of the drone in the three-dimensional positioning coordinate system, and naming them as coordinates to be calibrated;

[0140] Step S4013, obtaining the location of the flight control system through GPS, marked as system location, calculating the distances between the system location and the first base station location, the second base station location, and the third base station location through a distance calculation formula, marked as the first coordinate distance, the second coordinate distance, and the third coordinate distance, respectively;

[0141] Step S4014, marking the base station in the three-dimensional positioning coordinate system based on the first coordinate distance, the second coordinate distance and the third coordinate distance, the base station includes base station No. 1, base station No. 2 and base station No. 3, and the angle of the base station relative to the flight control system can be obtained by GPS positioning;

[0142] Step S4015, obtaining the coordinates of base station No. 1, base station No. 2, and base station No. 3, which are marked as coordinate No. 1, coordinate No. 2, and coordinate No. 3 respectively;

[0143] Step S402, analyzing and calculating the calibration points of the drone on the X-axis and the Y-axis;

[0144] Step S402 includes the following sub-steps:

[0145] Step S4021, calculating the average value of the first positioning distance and the first interaction distance, and naming the calculation result as the first average distance; calculating the average value of the second positioning distance and the second interaction distance, and naming the calculation result as the second average distance; calculating the average value of the third positioning distance and the third interaction distance, and naming the calculation result as the third average distance;

[0146] Step S4022, with the first coordinate as the endpoint, a straight line is drawn to the coordinate to be calibrated, named as the first straight line, the length of the first straight line is the first average distance, and the other endpoint of the first straight line is named as the first endpoint;

[0147] Step S4023, taking the second coordinate as an endpoint, drawing a straight line to the coordinate to be calibrated, and naming it the second straight line. The length of the second straight line is the second average distance, and the other endpoint of the second straight line is named the second endpoint.

[0148] Step S4024, taking the third coordinate as an endpoint, drawing a straight line to the coordinate to be calibrated, and naming it the third straight line. The length of the third straight line is the third average distance, and the other endpoint of the third straight line is named the third endpoint.

[0149] Step S4025, connecting endpoint 1, endpoint 2, and endpoint 3, and naming the resulting triangle as a calibration triangle, and marking the coordinates of the geometric center of the calibration triangle as an XY calibration point;

[0150] Step S403, analyzing and calculating the calibration value of the UAV on the Z axis, and calibrating the three-dimensional coordinates of the UAV in the flight control system;

[0151] Step S403 includes the following sub-steps:

[0152] Step S4031, obtaining the incident angle of the return signal of the UAV through the flight control system, which is named as the signal incident angle. The signal incident angle is the angle between the return signal and the horizontal ground;

[0153] Step S4032, obtaining the X coordinate and Y coordinate of the XY calibration point, which are marked as the X-axis calibration value and the Y-axis calibration value respectively;

[0154] Step S4033, calculating the Z-axis calibration value of the coordinate to be calibrated by using the Z-axis calibration formula;

[0155] The Z-axis calibration formula is configured as: , where JZ is the Z-axis calibration value, JX is the X-axis calibration value, JY is the Y-axis calibration value, and θ is the signal incident angle;

[0156] Step S4034, obtaining the X, Y and Z of the coordinates to be calibrated, and naming them as the X value to be calibrated, the Y value to be calibrated and the Z value to be calibrated respectively;

[0157] Step S4035, calculate the X-axis calibration value minus the X value to be calibrated to obtain the X calibration value; calculate the Y-axis calibration value minus the Y value to be calibrated to obtain the Y calibration value; calculate the Z-axis calibration value minus the Z value to be calibrated to obtain the Z calibration value;

[0158] Step S4036, calibrate the coordinates to be calibrated of the drone in the three-dimensional positioning coordinate system obtained each time, increase X by the X calibration value, increase Y by the Y calibration value, and increase Z by the Z calibration value.

[0159] Embodiment 3, in the third aspect, the present application provides an electronic device, including a processor and a memory, the memory storing computer-readable instructions, and when the computer-readable instructions are executed by the processor, the steps in the above method are executed. Through the above technical solution, the processor and the memory are interconnected and communicate with each other through a communication bus and / or other forms of connection mechanisms, and the memory stores a computer program executable by the processor. When the electronic device is running, the processor executes the computer program to execute the method in any optional implementation of the above embodiment to achieve the following functions: obtain the positioning of the drone and the positioning of the nearby base station based on GPS positioning; calculate the distance between the drone and the base station based on the initial positioning point and the base station positioning point, marked as the positioning distance; exchange information between the drone and the base station, calculate the distance between the drone and the base station based on the interaction duration, marked as the interaction distance; establish a three-dimensional coordinate system based on the position information of the drone's flight control system, and calibrate the three-dimensional coordinates of the drone by analyzing the positioning distance and the interaction distance.

[0160] Embodiment 4, fourth aspect, the present application provides a storage medium, on which a computer program is stored, and when the computer program is executed by a processor, the steps in the above method are executed. Through the above technical solution, when the computer program is executed by the processor, the method in any optional implementation of the above embodiment is executed to achieve the following functions: obtain the positioning of the drone and the positioning of the nearby base station based on GPS positioning; calculate the distance between the drone and the base station based on the initial positioning point and the base station positioning point, marked as the positioning distance; through the information exchange between the drone and the base station, calculate the distance between the drone and the base station based on the interaction time, marked as the interaction distance; establish a three-dimensional coordinate system based on the position information of the drone's flight control system, and calibrate the three-dimensional coordinates of the drone by analyzing the positioning distance and the interaction distance.

[0161] In the above embodiments of the present application, the description of each embodiment has its own emphasis. For parts that are not described in detail in a certain embodiment, please refer to the relevant description of other embodiments.

[0162] It should be understood by those skilled in the art that the embodiments of the present invention may be provided as methods, systems or computer program products. Therefore, the present invention may take the form of a complete hardware embodiment, a complete software embodiment or an embodiment combining software and hardware aspects. Moreover, the present invention may take the form of a computer program product implemented on one or more computer-usable storage media containing computer-usable program codes. Among them, the storage medium may be implemented by any type of volatile or non-volatile storage device or a combination thereof, such as static random access memory (Static Random Access Memory, referred to as SRAM), electrically erasable programmable read-only memory (Electrically Erasable Programmable Read-Only Memory, referred to as EEPROM), erasable programmable read-only memory (Erasable Programmable Read-Only Memory, referred to as EPROM), programmable read-only memory (Programmable Read-Only Memory, referred to as PROM), read-only memory (Read-Only Memory, referred to as ROM), magnetic memory, flash memory, magnetic disk or optical disk. These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0163] In the embodiments provided in the present application, it should be understood that the disclosed devices and methods can be implemented in other ways. The device embodiments described above are merely schematic. For example, the division of the units is only a logical function division. There may be other division methods in actual implementation. For example, multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some communication interfaces, and the indirect coupling or communication connection of devices or units can be electrical, mechanical or other forms.

Claims

1. A UAV coordinate calibration method based on three-dimensional coordinates, characterized in that: The steps include: Based on GPS positioning, the positioning of the drone is obtained and marked as the initial positioning point. At the same time, the positioning of the base station near the drone is obtained and marked as the base station positioning point. The distance between the drone and the base station is calculated based on the initial positioning point and the base station positioning point, and marked as the positioning distance; The drone exchanges information with the base station, records the time between sending and receiving information, and marks it as interaction time. The distance between the drone and the base station is calculated based on the interaction time, and marked as interaction distance. A three-dimensional coordinate system is established based on the position information of the UAV's flight control system, and the three-dimensional coordinates of the UAV are calibrated by analyzing the positioning distance and the interaction distance; The three-dimensional coordinate system is established based on the position information of the UAV's flight control system. The three-dimensional coordinates of the UAV are calibrated by analyzing the positioning distance and the interaction distance, including the following sub-steps: A three-dimensional positioning coordinate system is established based on the position information of the flight control system of the UAV, and the coordinates of the base station are marked in the three-dimensional positioning coordinate system; Analyze and calculate the calibration points of the drone on the X-axis and Y-axis; Analyze and calculate the calibration value of the drone on the Z axis, and calibrate the three-dimensional coordinates of the drone in the flight control system; Establishing a three-dimensional positioning coordinate system based on the position information of the flight control system of the UAV and marking the coordinates of the base station in the three-dimensional positioning coordinate system includes the following sub-steps: A three-dimensional coordinate system is established with the position of the UAV's flight control system as the origin, the east as the X axis, the north as the Y axis, and the vertical upward as the Z axis, and is named the three-dimensional positioning coordinate system; Get the coordinates of the drone in the three-dimensional positioning coordinate system and name them as the coordinates to be calibrated; The positioning of the flight control system is obtained through GPS, which is marked as the system positioning. The distances between the system positioning and the first base station positioning, the second base station positioning, and the third base station positioning are calculated through the distance calculation formula, which are marked as the first coordinate distance, the second coordinate distance, and the third coordinate distance respectively; Based on the first coordinate distance, the second coordinate distance and the third coordinate distance, the base stations are marked in the three-dimensional positioning coordinate system, wherein the base stations include base station No. 1, base station No. 2 and base station No. 3, and the angle of the base station relative to the flight control system can be obtained by GPS positioning; Obtain the coordinates of base station No. 1, base station No. 2, and base station No. 3, and mark them as coordinate No. 1, coordinate No. 2, and coordinate No. 3 respectively; Analyzing and calculating the calibration points of the drone on the X-axis and Y-axis includes the following sub-steps: Calculate the average value of the first positioning distance and the first interaction distance, and name the calculation result as the first average distance; calculate the average value of the second positioning distance and the second interaction distance, and name the calculation result as the second average distance; Calculate the average of the third positioning distance and the third interaction distance, and name the calculation result as the third average distance; Taking coordinate No. 1 as an endpoint, draw a straight line to the coordinate to be calibrated, named as straight line No. 1, the length of straight line No. 1 is the first average distance, and the other endpoint of straight line No. 1 is named as endpoint No. 1; Taking the second coordinate as an endpoint, draw a straight line to the coordinate to be calibrated, named as the second straight line, the length of the second straight line is the second average distance, and the other endpoint of the second straight line is named as the second endpoint; Taking the third coordinate as an endpoint, a straight line is drawn to the coordinate to be calibrated, and the straight line is named as the third straight line. The length of the third straight line is the third average distance, and the other endpoint of the third straight line is named as the third endpoint. Connect endpoints 1, 2, and 3 to obtain a triangle named a calibration triangle, and mark the coordinates of the geometric center of the calibration triangle as an XY calibration point.

2. The method for calibrating drone coordinates based on three-dimensional coordinates according to claim 1, characterized in that: Obtaining the location of the drone based on GPS positioning, marking it as the initial positioning point, and obtaining the location of the base station near the drone includes the following sub-steps: The location of the drone is obtained based on GPS positioning, which is marked as the initial positioning point. The initial positioning point is (lat0, lon0), where lat0 is the latitude of the initial positioning point and lon0 is the longitude of the initial positioning point. Obtain the positions of the three base stations closest to the drone, which are marked as the first base station positioning point, the second base station positioning point, and the third base station positioning point, respectively. The first base station positioning point, the second base station positioning point, and the third base station positioning point are collectively referred to as base station positioning points; The first base station positioning point includes (lat1, lon1), wherein lat1 is the latitude of the first base station positioning point, and lon1 is the longitude of the first base station positioning point; the second base station positioning point includes (lat2, lon2), wherein lat2 is the latitude of the second base station positioning point, and lon2 is the longitude of the second base station positioning point; the third base station positioning point includes (lat3, lon3), wherein lat3 is the latitude of the third base station positioning point, and lon3 is the longitude of the third base station positioning point.

3. The method for calibrating drone coordinates based on three-dimensional coordinates according to claim 2, characterized in that: Calculating the distance between the drone and the base station based on the initial positioning point and the base station positioning point, marked as the positioning distance, includes the following sub-steps: Calculate the positioning distance between the drone and the base station using the distance calculation formula; The distance calculation formula is configured as: Among them, lat n is lat1, lat2 or lat3, lon n is lon1, lon2 or lon3, atan2 is the inverse tangent function, R is the radius of the earth, D n is the positioning distance, b is the intermediate variable, and c is the arc difference between the initial positioning point and the base station positioning point; The positioning distance includes a first positioning distance D1, a second positioning distance D2 and a third positioning distance D3.

4. The method for calibrating drone coordinates based on three-dimensional coordinates according to claim 3, characterized in that: The drone exchanges information with the base station, records the time between sending and receiving the information, and marks it as the interaction time. The distance between the drone and the base station is calculated based on the interaction time, and marked as the interaction distance. The steps are as follows: The drone exchanges information with the base station, and the time between sending and receiving the information is recorded, which is marked as the interaction time. The interaction time includes the first interaction time, the second interaction time and the third interaction time, which correspond to the three base stations respectively. Obtain a radio wave propagation speed, multiply the radio wave propagation speed by the first interaction duration, and then divide by 2 to obtain a first interaction distance; Multiply the radio wave propagation speed by the second interaction duration and divide by 2 to obtain the second interaction distance; Multiply the radio wave propagation speed by the third interaction duration and divide by 2 to obtain the third interaction distance.

5. The method for calibrating drone coordinates based on three-dimensional coordinates according to claim 4, characterized in that: Analyzing and calculating the calibration value of the drone on the Z axis and calibrating the three-dimensional coordinates of the drone in the flight control system includes the following sub-steps: The incident angle of the return signal of the UAV is obtained through the flight control system, which is named as the signal incident angle. The signal incident angle is the angle between the return signal and the horizontal ground; Get the X coordinate and Y coordinate of the XY calibration point, marked as X-axis calibration value and Y-axis calibration value respectively; Calculate the Z-axis calibration value of the coordinate to be calibrated by using the Z-axis calibration formula; The Z-axis calibration formula is configured as: , where JZ is the Z-axis calibration value, JX is the X-axis calibration value, JY is the Y-axis calibration value, and θ is the signal incident angle; Get the X, Y and Z of the coordinates to be calibrated, and name them as X value to be calibrated, Y value to be calibrated and Z value to be calibrated respectively; Calculate the X-axis calibration value minus the X value to be calibrated to obtain the X calibration value; calculate the Y-axis calibration value minus the Y value to be calibrated to obtain the Y calibration value; calculate the Z-axis calibration value minus the Z value to be calibrated to obtain the Z calibration value; Calibrate each acquired coordinate of the drone in the three-dimensional positioning coordinate system to be calibrated, increase X by the X calibration value, increase Y by the Y calibration value, and increase Z by the Z calibration value.

6. A drone coordinate calibration system based on three-dimensional coordinates, used to implement the drone coordinate calibration method based on three-dimensional coordinates according to any one of claims 1 to 5, characterized in that: It includes a GPS positioning module, a positioning distance calculation module, an interactive distance calculation module and a three-dimensional coordinate calibration module; the GPS positioning module, the positioning distance calculation module and the interactive distance calculation module are respectively connected to the three-dimensional coordinate calibration module data; The GPS positioning module is used to obtain the location of the UAV based on GPS positioning, marked as the initial positioning point, and simultaneously obtain the location of the base station near the UAV, marked as the base station positioning point; The positioning distance calculation module is used to calculate the distance between the UAV and the base station based on the initial positioning point and the base station positioning point, which is marked as the positioning distance; The interaction distance calculation module is used to interact with the base station through the drone, record the time between sending and receiving the information, marked as the interaction time, and calculate the distance between the drone and the base station based on the interaction time, marked as the interaction distance; The three-dimensional coordinate calibration module is used to establish a three-dimensional coordinate system based on the position information of the flight control system of the UAV, and calibrate the three-dimensional coordinates of the UAV by analyzing the positioning distance and the interaction distance.

7. A storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps of the method according to any one of claims 1 to 5 are performed.

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