LU507939B1

LU507939B1 - Unmanned aerial vehicle positioning system and method under denial conditions

Info

Publication number: LU507939B1
Application number: LU507939A
Authority: LU
Inventors: Fei Wang; Xingguang Yang; Lei Shao; Huichao Jia; Donghai Li; Jun Ma; Yanxiang Sun; Chengming Fan; Liqiao Duan; Ping Zhang; Jingwen Guo; Kangning Song
Original assignee: Aerospace Science And Industry Simulation Tech Co Ltd; Hebei Jixiangtong Electronic Tech Co Ltd
Priority date: 2024-08-06
Filing date: 2024-08-06
Publication date: 2025-02-06

Abstract

The present invention relates to the technical field of unmanned aerial vehicle (UAV) positioning, and discloses an unmanned aerial vehicle positioning system and method under denial conditions. The present invention can effectively obtain various positioning information of the UAV under denial conditions through altitude information acquisition device, horizontal information acquisition device, heading information acquisition device, and comprehensive information acquisition device, thereby improving the accuracy of the positioning information; on this basis, the supplementary position information of the UAV is obtained by the comprehensive information acquisition device to further supplement the above altitude information, horizontal information, and heading information, resulting in more accurate positioning information; finally, through the fusion processing of the data fusion device, the accurate positioning information of the UAV can be obtained, thereby improving the accuracy and reliability of the positioning information. (FIG. 1)

Description

DESCRIPTION LU507939

UNMANNED AERIAL VEHICLE POSITIONING SYSTEM AND METHOD UNDER

DENIAL CONDITIONS

TECHNICAL FIELD

The present invention relates to the field of unmanned aerial vehicle positioning technology, specifically to an unmanned aerial vehicle positioning system and method under denial conditions.

BACKGROUND

Unmanned aerial vehicles (UAVs) are increasingly being used in the national economy and military. Currently, UAVs mainly rely on global navigation satellite systems (such as GPS of the United States and Beidou System of China) for positioning and navigation.

Satellite signals themselves are electromagnetic signals. The average altitude of navigation satellites from the Earth’s surface is 20,000 to 21,500 kilometers. The signals emitted from navigation satellites are already very weak when they reach the Earth’s surface, making navigation signals more vulnerable to interference. What's more serious is that navigation satellite signals cannot be received at all. When the navigation satellite signal is interfered with, or the receiver receives a false satellite signal, in short, any situation where the navigation satellite signal is abnormal, we collectively call it a navigation satellite signal denial situation. In the case of navigation satellite signal denial, it will cause serious consequences for UAVs that rely on navigation satellites for navigation, resulting in crashes or hijackings.

SUMMARY LU507939

In view of this, the present invention provides an unmanned aerial vehicle (UAV) positioning system and method under denial conditions to solve the positioning problem under UAV denial conditions.

In the first aspect, the present invention provides an unmanned aerial vehicle positioning system under denial conditions, the system includes: an altitude information acquisition device for obtaining an altitude information set of the UAV, the altitude information set comprising at least one sub-altitude information; a horizontal information acquisition device for obtaining a horizontal information set of the UAV, the horizontal information set comprising at least one sub-horizontal information; a heading information acquisition device for obtaining a heading information set of the UAV, the heading information set comprising at least one sub-heading information; a comprehensive information acquisition device for obtaining supplementary position information of the UAV; and a data fusion device for determining the positioning information of the UAV according to the at least one sub-altitude information, the at least one sub-horizontal information, the at least one sub-heading information, and the supplementary position information.

Beneficial effects: through the altitude information acquisition device, horizontal information acquisition device, heading information acquisition device, and comprehensive information acquisition device, various positioning information of the

UAV under denial conditions can be effectively obtained, improving the accuracy of the positioning information; on this basis, the comprehensive information acquisition device acquires supplementary position information of the UAV to further supplement the above altitude information, horizontal information, and heading information to obtain more accurate positioning information; finally, through the data fusion device for fusion processing to obtain the precise positioning information of the UAV, improving the accuracy and reliability of the positioning information.

In an alternative embodiment, the altitude information acquisition device includes: LU507939 a barometer for obtaining the altitude information of the UAV; and a radio altimeter for obtaining the first ground-to-air altitude information of the UAV.

In an alternative embodiment, the horizontal information acquisition device includes: an accelerometer for obtaining acceleration information from the first time to the current time, the first time being the last time a GPS signal is obtained; and a radio receiving terminal for obtaining the radio frequency of the radio waves sent by the earth, the acceleration information and the radio frequency constituting the horizontal information set.

In an alternative embodiment, the heading information acquisition device includes: a gyroscope for obtaining the first heading angle of the UAV; and a magnetic compass for obtaining the relative change of the UAV from the first time to the current time, the first heading angle and the relative change constituting the heading information set.

In an alternative embodiment, the comprehensive information acquisition device includes: a millimeter-wave radar for obtaining the second ground-to-air altitude; a binocular camera for obtaining image information, the image information can obtain environmental information around the UAV; and a lidar for obtaining the first geographical environment information corresponding to the UAV.

In an alternative embodiment, the data fusion device includes: an altitude fusion module for determining the final altitude information according to the at least one sub-altitude information and the second ground-to-air altitude; a horizontal fusion module for determining the final horizontal information according to the at least one sub-horizontal information, the environmental information and the first geographical environment information; a heading fusion module for determining the final heading information according to the at least one sub-heading information and the environmental information; and a total fusion module for determining the positioning information according to the final altitude information, the final horizontal information and the final heading information. LU507939

In an alternative embodiment, the comprehensive information acquisition device is further configured to acquire an obstacle information set, the obstacle information set including obstacle altitude information, environmental information, and obstacle environmental information.

In an alternative embodiment, the data fusion device further includes: an obstacle fusion module for determining the final obstacle information according to the at least one obstacle information.

In an alternative embodiment, the system further includes: a flight path planning module for determining a UAV flight path according to the positioning information, the final obstacle information, and a pre-acquired target position.

In the second aspect, the present invention provides an unmanned aerial vehicle positioning method under denial conditions, which is applied to the UAV positioning device under denial conditions in the first aspect or any optional implementation manner of the first aspect, the method including: obtaining the altitude information set of the UAV, the altitude information set including at least one sub-altitude information; obtaining the horizontal information set of the UAV, the horizontal information set including at least one sub-horizontal information; obtaining the heading information set of the UAV, the heading information set including at least one sub-heading information; obtaining the supplementary position information of the UAV; and determining the positioning information of the UAV according to the at least one sub-altitude information, the at least one sub-horizontal information, the at least one sub-heading information, and the supplementary position information.

BRIEF DESCRIPTION OF THE FIGURES LU507939

In order to more clearly illustrate the technical solutions in the specific embodiments or the prior art of the present invention, the following will briefly introduce the drawings that need to be used in the specific embodiments or the description of the prior art.

Obviously, the drawings in the following description are some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

FIG. 1 is a schematic diagram of an unmanned aerial vehicle positioning system under denial conditions according to an embodiment of the present invention;

FIG. 2 is a schematic diagram of an unmanned aerial vehicle positioning system under denial conditions according to an embodiment of the present invention;

FIG. 3 is a schematic diagram of an unmanned aerial vehicle positioning system under denial conditions according to an embodiment of the present invention;

FIG. 4 is a flowchart of an unmanned aerial vehicle positioning method under denial conditions according to an embodiment of the present invention.

DESCRIPTION OF THE INVENTION

To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts fall within the protection scope of the present invention.

According to an embodiment of the present invention, an embodiment for an unmanned aerial vehicle (UAV) positioning system under denial conditions is provided.

It should be noted that the steps shown in the flowchart of the accompanying/507939 drawings can be executed in a computer system such as a set of computer-executable instructions, and although the logical order is shown in the flowchart, in some cases, the steps shown or described may be executed in a different order from here.

In this embodiment, an unmanned aerial vehicle positioning system under denial conditions is provided. FIG. 1 is a schematic diagram of the unmanned aerial vehicle positioning system under denial conditions according to an embodiment of the present invention. As shown in FIG. 1, the system includes:

An altitude information acquisition device 101, used to obtain the altitude information set of the UAV, and the altitude information set includes at least one sub-altitude information.

For example, when the UAV is in denial conditions, it is impossible to obtain positioning information of the current position through GPS, so it is necessary to obtain the current position of the UAV according to the built-in device of the UAV, which specifically may include the altitude position, horizontal (latitude and longitude) position, and current heading information of the UAV. Here, the altitude position can be based on sonar device, etc., using sound signals to measure the distance between the UAV and the ground or other objects, thereby obtaining altitude information.

Specifically, in an optional embodiment, the altitude information acquisition device includes: a barometer, used to obtain the altitude information of the UAV; a radio altimeter, used to obtain the first ground-to-air altitude information of the UAV.

For example, UAVs are generally equipped with barometers and radio altimeters, etc. In this case, the altitude information of the barometer corresponding to the current moment can be obtained. The altitude information is also the absolute coordinate of the current UAV in the earth, which has high reference value. However, the barometer is easily affected by changes in wind speed, temperature, etc. during operation, resulting in low measurement accuracy. In this case, the ground-to-air altitude can be measured according to the radio altimeter, and the measurement range is generally from 10 meters to 2,000 meters, and the measurement accuracy is up to the sub-meter level. In combination with the value of the barometer, more accurate UAV altitude information can be obtained.

A horizontal information acquisition device 102, used to obtain the horizontall507939 information set of the UAV, and the horizontal information set includes at least one sub-horizontal information.

For example, the horizontal information is the latitude and longitude information corresponding to the UAV at the current moment. In this case, since there is no accurate

GPS signal, the accurate latitude and longitude information can be determined by local high-precision horizontal position information acquisition plus wide-area low-precision horizontal position information acquisition. Specifically, methods such as magnetic field positioning can be used to determine the position of the UAV on the horizontal plane by using the variation law of the earth’s magnetic field. The site is pre-mapped for the magnetic field, and the corresponding magnetic field sensor is installed on the UAV.

In an optional embodiment, the horizontal information acquisition device includes:

An accelerometer for obtaining acceleration information from the first time to the current time, the first time being the last time a GPS signal is obtained; a radio receiving terminal for obtaining the radio frequency of the radio waves sent by the earth, the acceleration information and the radio frequency constituting the horizontal information set.

For example, a corresponding accelerometer can be selected, such as a high-precision, low-noise accelerometer, such as a silicon micromachined accelerometer or a quartz accelerometer. The accelerometer is installed at the center of gravity of the

UAV to minimize the error introduced due to the change in the attitude of the UAV. By reading the output value of the accelerometer, the acceleration values of the UAV in the three axes (X, Y, Z) can be calculated. By integrating these values, combined with the position information corresponding to the last GPS signal, the speed and position information of the UAV at the current time can be obtained.

Radio receiving terminal: Select a radio receiver with high sensitivity, low noise and wide bandwidth. Install the radio receiver on the outside of the UAV to be able to receive as many radio signals as possible. The radio frequency information received by the radio receiver can be used for positioning and navigation. For example, radio frequency information can be used for multipath positioning or relative positioning with known radio transmitters.

A heading information acquisition device 103, used to obtain the heading/507939 information set of the UAV, and the heading information set includes at least one sub-heading information.

For example, when collecting heading information, a radio direction-finding system can be used to determine the heading information of the UAV by using the change of the signal strength or phase in different directions. This system usually requires a plurality of radio signal sources to be preset, and it is necessary to measure the relative position of the UAV and the change of the signal strength or phase to determine the heading information.

A visual heading indicator can also be used: A visual heading indicator is a device that uses optical principles to indicate the heading of a UAV. This device usually needs to be installed on the UAV and point to the flight direction of the UAV. By observing the indicator mark on the visual heading indicator, the heading information of the UAV can be determined.

In an optional embodiment, the heading information acquisition device includes: a gyroscope for obtaining the first heading angle of the UAV; and a magnetic compass for obtaining the relative change of the UAV from the first time to the current time, the first heading angle and the relative change constitute the heading information set.

For example, the magnetic compass uses the earth’s magnetic field to measure the heading of the UAV. The magnetic compass usually needs to be installed on the UAV and point to the flight direction of the UAV. By measuring the direction of the earth's magnetic field, the heading information of the UAV can be determined. The gyroscope can measure the angular velocity and rotation direction of the UAV. By integrating the output value of the gyroscope, the heading information of the UAV can be determined.

The gyroscope usually needs to be connected to the UAV to obtain heading data from the UAV.

A comprehensive information acquisition device 104, used to obtain the supplementary position information of the UAV.

For example, in the above information acquisition device, there may be interference from the weather or the environment in which the UAV is located, resulting in inaccurate or unavailable information acquisition.

Therefore, in order to further ensure the accuracy of information acquisition and)507939 improve the positioning accuracy of the UAV, a comprehensive information acquisition device is set up to supplement the above information.

Specifically, an image acquisition device can be set up to acquire image information around the UAV, and the above information, such as altitude information, heading information, and horizontal information, can be supplemented based on the image information. Specifically, the environmental information in the image information can be identified, and the environmental information can be compared with the built-in map to obtain the exact position of the UAV in the map to determine the corresponding altitude, horizontal, and heading information.

In an optional embodiment, a millimeter-wave radar is used to obtain the second ground-to-air altitude; a binocular camera is used to obtain image information, and the image information can obtain environmental information around the UAV; a lidar is used to obtain the first geographic environment information corresponding to the UAV.

For example, millimeter-wave radar can measure a range from generally 0 meters to 1000 meters. Short-range millimeter-wave radar is mainly used on UAVs, and the measurement accuracy is up to the centimeter level, which can more accurately obtain the altitude information of the UAV on the basis of the altitude information acquisition device in the above embodiment; secondly, a binocular camera is set, and according to the built-in parameters in the binocular camera and the environmental information in the image information, the altitude information, horizontal information, and heading information of the UAV can be accurately determined.

Specifically, for the comprehensive information acquisition device, a barometer plus radio altimeter plus millimeter-wave radar plus binocular camera plus lidar constitute a high-reliability system for measuring altitude and relative altitude, with an accuracy of up to millimeter level; binocular camera plus lidar plus accelerometer plus radio receiving terminal achieve accurate acquisition of horizontal information, the binocular camera and lidar extract the surrounding terrain environment features, and match them with the features of the digital map (built-in or pre-constructed) to obtain its own horizontal position (ie, latitude and longitude coordinates) in the digital map, and the accelerometer estimates the horizontal position of the UAV through dead reckoning, and the radio receiving terminal is to receive radio waves of a specific frequency through the antennaäU507939 measure the distance from the signal source of the known earth coordinate system, and realize its own positioning; binocular camera plus magnetic compass plus gyroscope to achieve the acquisition of heading information.

A data fusion device 105, used to determine the positioning information of the UAV according to at least one sub-altitude information, at least one sub-horizontal information, at least one sub-heading information, and supplementary position information.

For example, specifically, the corresponding information in the acquired altitude information set, horizontal information set, and heading information set can be preprocessed to obtain accurate positioning information. Specifically, a Kalman filter can be used to process sensor data with noise. By inputting sensor data such as altitude, horizontal, and heading into the Kalman filter, the data can be optimized and fused to improve the positioning accuracy of the UAV. The least squares method can also be used to solve linear equations. By inputting the data of multiple sensors into the least squares algorithm, the UAV position information closest to the true value can be solved.

In an optional embodiment, the data fusion device includes: an altitude fusion module for determining the final altitude information according to the at least one sub-altitude information and the second ground-to-air altitude; a horizontal fusion module for determining the final horizontal information according to the at least one sub-horizontal information, the environmental information and the first geographical environment information; a heading fusion module for determining the final heading information according to the at least one sub-heading information and the environmental information; and a total fusion module for determining the positioning information according to the final altitude information, the final horizontal information and the final heading information.

For example, use a certain algorithm or logic to combine the information in tH&J507939 altitude information set. For example, these pieces of information can be combined with a weight function to determine the final altitude based on the reliability and accuracy of each input altitude information; the fusion of horizontal information and the fusion of heading information can both use this method to determine the final information, improving the accuracy of the information.

On the basis of the above embodiment, the comprehensive information acquisition device is also used to acquire the obstacle information set, and the obstacle information set includes the obstacle altitude information, the environment information, and the obstacle environment information.

For example, during the flight of the UAV, it is also necessary to accurately obtain the surrounding obstacle information to avoid the UAV colliding with the obstacle during the navigation process. Specifically, the corresponding obstacle information can be obtained by using the comprehensive information acquisition device to obtain the obstacles around the UAV.

On this basis: the obstacle fusion module is used to determine the final obstacle information according to at least one obstacle information and the environment information. Millimeter-wave radar plus binocular camera plus lidar can real-time build the surrounding environment, identify obstacles, and when the navigation computer plans the route, it can reasonably avoid obstacles according to the position of the obstacles.

The system also includes: a flight path planning module for determining a UAV flight path according to the positioning information, the final obstacle information, and a pre-acquired target position. Through “millimeter-wave radar plus binocular camera plus lidar”, the surrounding environment can be constructed in real time, obstacles can be identified, and when the navigation computer plans the route, it can reasonably avoid obstacles according to the position of the obstacles.

Next, a specific example is used to further introduce the content in the abowé/507939 embodiment. As shown in FIG. 2 and FIG. 3, in the absence of GPS signals, multiple sensors are used to obtain the altitude information, horizontal position information, and three attitude angle information (heading information) of the UAV, and the latitude, longitude, and altitude information of the UAV is obtained through an information fusion algorithm. During long-term navigation, due to measurement noise and system errors of a single sensor information, the information accumulated by integrating this signal will have a large cumulative error, resulting in complete information distortion. For example, using only an accelerometer for position calculation may lead to similar problems. By using multiple types of sensors, some sensors directly output position and attitude information, some output speed and acceleration information, some sensors collect local information to improve positioning accuracy, and some sensors collect large-range low-precision information. Through information fusion technology, the problem of unable to navigate or low navigation accuracy in the case of long-term navigation satellite signal rejection is completely solved, enabling the UAV to achieve reliable long-term navigation in the environment of navigation satellite signal rejection.

In this embodiment, an unmanned aerial vehicle positioning method under denial conditions is also provided, which is used to implement the above embodiments and optional embodiments, and will not be repeated if it has been described.

This embodiment provides an unmanned aerial vehicle positioning method under denial conditions, as shown in FIG. 4, which is applied to the unmanned aerial vehicle positioning system under the denial conditions in the above embodiment, and the method includes:

Step 401, obtaining the altitude information set of the UAV, the altitude information set including at least one sub-altitude information;

Step 402, obtaining the horizontal information set of the UAV, the horizontal information set including at least one sub-horizontal information;

Step 403, obtaining the heading information set of the UAV, the heading information set including at least one sub-heading information;

Step 404, obtaining the supplementary position information of the UAV; and

Step 405, determining the positioning information of the UAV according to at least one sub-altitude information, at least one sub-horizontal information, at least orl&J507939 sub-heading information, and supplementary position information.

The implementation methods of the above steps are the same as the corresponding embodiments, and will not be repeated here.

Claims

CLAIMS LU507939

1. An unmanned aerial vehicle (UAV) positioning system under denial conditions, characterized in that the system comprises: an altitude information acquisition device for obtaining an altitude information set of the UAV, the altitude information set comprising at least one sub-altitude information; a horizontal information acquisition device for obtaining a horizontal information set of the UAV, the horizontal information set comprising at least one sub-horizontal information; a heading information acquisition device for obtaining a heading information set of the UAV, the heading information set comprising at least one sub-heading information; a comprehensive information acquisition device for obtaining supplementary position information of the UAV; and a data fusion device for determining the positioning information of the UAV according to the at least one sub-altitude information, the at least one sub-horizontal information, the at least one sub-heading information, and the supplementary position information.

2. The system according to claim 1, characterized in that the altitude information acquisition device comprises: a barometer for obtaining the altitude information of the UAV; and a radio altimeter for obtaining the first ground-to-air altitude information of the UAV.

3. The system according to claim 2, characterized in that the horizontal information acquisition device comprises: an accelerometer for obtaining acceleration information from the first time to the current time, the first time being the last time a GPS signal is obtained; and a radio receiving terminal for obtaining the radio frequency of the radio waves sent by the earth, the acceleration information and the radio frequency constituting the horizontal information set.

4. The system according to claim 2 or 3, characterized in that the heading/507939 information acquisition device comprises: a gyroscope for obtaining the first heading angle of the UAV; and a magnetic compass for obtaining the relative change of the UAV from the first time to the current time, the first heading angle and the relative change constituting the heading information set.

5. The system according to claim 4, characterized in that the comprehensive information acquisition device comprises: a millimeter-wave radar for obtaining the second ground-to-air altitude; a binocular camera for obtaining image information, the image information can obtain environmental information around the UAV; and a lidar for obtaining the first geographical environment information corresponding to the UAV.

6. The system according to claim 5, characterized in that the data fusion device comprises: an altitude fusion module for determining the final altitude information according to the at least one sub-altitude information and the second ground-to-air altitude; a horizontal fusion module for determining the final horizontal information according to the at least one sub-horizontal information, the environmental information and the first geographical environment information; a heading fusion module for determining the final heading information according to the at least one sub-heading information and the environmental information; and a total fusion module for determining the positioning information according to the final altitude information, the final horizontal information and the final heading information.

7. The system according to claim 6, characterized in that the comprehensiugJ507939 information acquisition device is further configured to acquire an obstacle information set, the obstacle information set including obstacle altitude information, environmental information, and obstacle environmental information.

8. The system according to claim 7, characterized in that the data fusion device further comprises: an obstacle fusion module for determining the final obstacle information according to the at least one obstacle information.

9. The system according to claim 8, characterized in that the system further comprises: a flight path planning module for determining a UAV flight path according to the positioning information, the final obstacle information, and a pre-acquired target position.

10. An unmanned aerial vehicle positioning method under denial conditions, characterized in that it is applied to the unmanned aerial vehicle positioning system under denial conditions as described in any one of claims 1-9, the method comprising: obtaining the altitude information set of the UAV, the altitude information set comprising at least one sub-altitude information; obtaining the horizontal information set of the UAV, the horizontal information set comprising at least one sub-horizontal information; obtaining the heading information set of the UAV, the heading information set comprising at least one sub-heading information; obtaining the supplementary position information of the UAV; and determining the positioning information of the UAV according to the at least one sub-altitude information, the at least one sub-horizontal information, the at least one sub-heading information, and the supplementary position information.