System and method for positioning unmanned aerial vehicle under denial condition

Abstract

A system and method for positioning an unmanned aerial vehicle under a denial condition. Various types of positioning information of an unmanned aerial vehicle under a denial condition are effectively acquired by means of a height information acquisition device (101), a horizontal information acquisition device (102), a heading information acquisition device (103), and a comprehensive information acquisition device (104). The comprehensive information acquisition device (104) acquires supplementary position information of the unmanned aerial vehicle to further supplement height information, horizontal information, and heading information. Fusion processing is performed by means of a data fusion device (105) to obtain precise positioning information of the unmanned aerial vehicle, thereby improving the accuracy and reliability of the positioning information.

Description

UAV positioning system and method under denial conditions

[0001] This application claims priority to the Chinese patent application filed with the China Patent Office on December 6, 2023, with application number 202311669197.3 and invention name “UAV positioning system and method under denial conditions”, the entire contents of which are incorporated by reference into this application. Technical Field

[0002] The present application relates to the field of drone positioning technology, and in particular to a drone positioning system and method under denial conditions. Background Art

[0003] The application of drones in the national economy and military is becoming more and more extensive. Currently, drones mainly rely on global navigation satellite systems (the US GPS and China's Beidou system) for positioning and navigation.

[0004] Satellite signals are electromagnetic signals. Navigation satellites are located at an average altitude of 20,000 to 21,500 kilometers above the Earth's surface. The signals transmitted from these satellites are already very weak when they reach the Earth's surface, making them susceptible to interference. Even more serious is the complete loss of reception. Any abnormality in navigation satellite signals, including interference with navigation satellite signals or the reception of false satellite signals by the receiver, is collectively referred to as a navigation satellite signal denial. This can have serious consequences for drones that rely on navigation satellites for navigation, leading to crashes or hijackings.

[0005] Summary of the Invention

[0006] In view of this, the present application provides a drone positioning system and method under denied conditions to solve the drone positioning problem under denied conditions.

[0007] In a first aspect, the present application provides a drone positioning system under denial conditions, the system comprising:

[0008] An altitude information acquisition device is used to obtain an altitude information set of the UAV, wherein the altitude information set includes at least one sub-altitude information;

[0009] A level information acquisition device is used to obtain a level information set of the UAV, where the level information set includes at least one sub-level information;

[0010] A heading information acquisition device is used to obtain a heading information set of the UAV, where the heading information set includes at least one sub-heading information;

[0011] Comprehensive information acquisition equipment, used to obtain supplementary location information of the drone;

[0012] The data fusion device is used to determine the positioning information of the UAV based on at least one sub-altitude information, at least one sub-level information, at least one sub-heading information and the supplementary position information.

[0013] Beneficial effects: Through the altitude information acquisition equipment, horizontal information acquisition equipment, heading information acquisition equipment, and comprehensive information acquisition equipment, various types of positioning information of the UAV under denial conditions can be effectively obtained, thereby improving the accuracy of the positioning information; on this basis, the comprehensive information acquisition equipment obtains the supplementary position information of the UAV to further supplement the above-mentioned altitude information, horizontal information, and heading information to obtain more positioning information; finally, through the data fusion equipment, fusion processing is performed to obtain the precise positioning information of the UAV, thereby improving the accuracy and reliability of the positioning information.

[0014] In an optional embodiment, the height information collection device includes:

[0015] Barometer, used to obtain the altitude information of the drone;

[0016] Radio altimeter, used to obtain the first ground altitude information of the UAV.

[0017] In an optional embodiment, the horizontal information collection device includes:

[0018] An accelerometer, used to obtain acceleration information from a first moment to a current moment, where the first moment is the moment when the GPS signal was last obtained;

[0019] The radio receiving terminal is used to obtain the radio wave frequency sent by the earth, acceleration information and the horizontal information set composed of the radio wave frequency.

[0020] In an optional embodiment, the heading information collection device includes:

[0021] Gyroscope, used to obtain the first heading angle of the drone;

[0022] The magnetic compass is used to obtain the relative change of the drone from the first moment to the current moment. The first heading angle and the relative change constitute a heading information set.

[0023] In an optional embodiment, the comprehensive information acquisition device includes:

[0024] Millimeter-wave radar, used to obtain the second ground altitude;

[0025] Binocular camera, used to obtain image information, which can obtain environmental information around the drone;

[0026] The laser radar is used to obtain the first geographical environment information corresponding to the UAV.

[0027] In an optional embodiment, the data fusion device includes:

[0028] A height fusion module, configured to determine final height information based on at least one sub-height information and a second height relative to the ground;

[0029] a horizontal fusion module, configured to determine final horizontal information based on at least one sub-level information, environmental information, and first geographic environment information;

[0030] A heading fusion module, configured to determine final heading information based on at least one sub-heading information and environmental information;

[0031] The overall fusion module is used to determine the positioning information based on the final altitude information, the final level information and the final heading information.

[0032] In an optional embodiment, the apparatus further includes a comprehensive information acquisition device further configured to acquire an obstacle information set, wherein the obstacle information set includes obstacle height information, environmental information, and obstacle environment information.

[0033] In an optional embodiment, the data fusion device further includes:

[0034] The obstacle fusion module is used to determine final obstacle information based on at least one obstacle information.

[0035] In an optional embodiment, the system further includes:

[0036] The trajectory planning module is used to determine the UAV route based on the positioning information, final obstacle information and pre-acquired target position.

[0037] In a second aspect, the present application provides a method for positioning a drone under denied conditions, which is applied to the drone positioning device under denied conditions according to the first aspect or any optional embodiment of the first aspect. The method includes:

[0038] Obtaining a height information set of the UAV, where the height information set includes at least one sub-height information;

[0039] Obtaining a level information set of the UAV, where the level information set includes at least one sub-level information;

[0040] Obtaining a heading information set of the UAV, where the heading information set includes at least one sub-heading information;

[0041] Obtain additional location information of the drone;

[0042] The positioning information of the UAV is determined 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 DRAWINGS

[0043] In order to more clearly illustrate the specific implementation methods of the present application or the technical solutions in the prior art, the following is a brief introduction to the drawings required for use in the specific implementation methods or the description of the prior art. Obviously, the drawings described below are some implementation methods of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0044] FIG1 is a schematic diagram of a drone positioning system under denial conditions according to an embodiment of the present application;

[0045] FIG2 is a schematic diagram of a drone positioning system under denial conditions according to an embodiment of the present application;

[0046] FIG3 is a schematic diagram of a UAV positioning system under denial conditions according to an embodiment of the present application;

[0047] FIG4 is a flow chart of a method for determining a UAV under a denial condition according to an embodiment of the present application. DETAILED DESCRIPTION

[0048] To make the purpose, technical solutions, and advantages of the embodiments of the present application more clear, the technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without making creative efforts shall fall within the scope of protection of this application.

[0049] According to an embodiment of the present application, a method embodiment for constructing an automatic naming model for arterial blood vessels is provided. It should be noted that the steps shown in the flowchart of the accompanying drawings can be executed in a computer system such as a set of computer-executable instructions, and although a logical order is shown in the flowchart, in some cases, the steps shown or described can be executed in an order different from that shown here.

[0050] In this embodiment, a drone positioning system under denied conditions is provided. FIG1 is a schematic diagram of a drone positioning system under denied conditions according to an embodiment of the present application. As shown in FIG1 , the system includes:

[0051] The altitude information acquisition device 101 is used to obtain an altitude information set of the UAV, where the altitude information set includes at least one sub-altitude information.

[0052] For example, when a drone is in a denied condition, it cannot obtain its current location information via GPS. Therefore, it is necessary to use the drone's built-in equipment to obtain the current location of the drone, which may include the drone's altitude, horizontal position (latitude and longitude), and current heading information. The altitude position can be obtained by using sonar equipment, etc., which uses sound signals to measure the distance between the drone and the ground or other objects to obtain altitude information.

[0053] Specifically, in an optional embodiment, the altitude information collection device includes: a barometer, used to obtain the altitude information of the drone; and a radio altimeter, used to obtain the first ground height information of the drone.

[0054] For example, drones typically have built-in barometers and radio altimeters. In this case, the barometer's altitude information corresponding to the current moment can be obtained. This altitude information, representing the drone's absolute coordinates on Earth, is highly valuable as a reference. However, barometers are easily affected by changes in wind speed, temperature, and other factors during operation, resulting in low measurement accuracy. In this case, the radio altimeter can be used to measure altitude above the ground. The measurement range is generally from 10 to 2000 meters, with sub-meter accuracy. Combined with the barometer value, this provides more accurate drone altitude information.

[0055] The horizontal information acquisition device 102 is used to obtain a horizontal information set of the UAV, where the horizontal information set includes at least one sub-horizontal information.

[0056] For example, horizontal information refers to the drone's current latitude and longitude. In the absence of an accurate GPS signal, accurate latitude and longitude can be determined by acquiring local high-precision horizontal position information combined with wide-area low-precision horizontal position information. Specifically, magnetic field positioning can be used to determine the drone's horizontal position using the changing patterns of the Earth's magnetic field. Pre-magnetic mapping of the site is performed, and corresponding magnetic field sensors are installed on the drone.

[0057] In an optional embodiment, the horizontal information acquisition device includes:

[0058] The accelerometer is used to obtain acceleration information from a first moment to the current moment, where the first moment is the moment when the GPS signal is last obtained; the radio receiving terminal is used to obtain the radio wave frequency sent by the earth. The acceleration information and the radio wave frequency constitute a horizontal information set.

[0059] For example, the corresponding accelerometer can be 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 drone to minimize errors introduced by changes in the drone's attitude. By reading the accelerometer output, the acceleration values ​​of the drone in the three axes (X, Y, and Z) can be calculated. By integrating these values ​​and combining them with the position information corresponding to the GPS signal, the drone's current speed and position information can be obtained.

[0060] Radio receiving terminal: Select a radio receiver with high sensitivity, low noise, and a wide bandwidth. Mount the radio receiver on the outside of the drone to maximize its reception of radio signals. The radio frequency information received by the radio receiver can be used for positioning and navigation. For example, this frequency information can be used for multipath positioning or relative positioning relative to known radio wave sources.

[0061] The heading information collection device 103 is used to obtain a heading information set of the UAV, where the heading information set includes at least one sub-heading information.

[0062] For example, when collecting heading information, a radio direction finding system can be used to determine the drone's heading information by utilizing changes in radio signal strength or phase in different directions. This system typically requires pre-setting multiple radio signal sources and measuring the drone's relative position and changes in signal strength or phase to determine the heading information.

[0063] Alternatively, a visual heading indicator (VHI) can be used: a device that uses optical principles to indicate the drone's heading. This device is typically mounted on the drone and pointed in the direction of flight. By observing the indicator on the VHI, the drone's heading can be determined.

[0064] In an optional embodiment, the heading information collection device includes: a gyroscope for obtaining a first heading angle of the drone; a magnetic compass for obtaining a relative change in the drone from a first moment to a current moment, and the first heading angle and the relative change constitute a heading information set.

[0065] For example, a magnetic compass uses the Earth's magnetic field to measure a drone's heading. The magnetic compass is typically mounted on the drone and pointed in the direction of the drone's flight. By measuring the direction of the Earth's magnetic field, the drone's heading can be determined. A gyroscope measures a drone's angular velocity and rotational direction. By integrating the gyroscope's output, the drone's heading can be determined. The gyroscope typically needs to be connected to the drone to obtain heading data.

[0066] The comprehensive information acquisition device 104 is used to obtain the supplementary position information of the drone.

[0067] For example, the above information acquisition device may be interfered by weather or the environment in which the drone is located, resulting in inaccurate or unavailable information. Therefore, to further ensure the accuracy of information acquisition and improve the positioning accuracy of the drone, a comprehensive information acquisition device is provided to supplement the above information.

[0068] Specifically, an image acquisition device can be set up to obtain image information around the drone, and the above-mentioned information height information, heading information and level information can be supplemented according to 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 drone in the map to determine the corresponding height, level and heading information.

[0069] In an optional embodiment, a millimeter wave radar is used to obtain a second height above the ground; a binocular camera is used to obtain image information, which can obtain environmental information around the drone; and a laser radar is used to obtain first geographical environment information corresponding to the drone.

[0070] For example, the millimeter-wave radar can measure a range from 0 meters to 1000 meters. The short-range millimeter-wave radar is mainly used on the UAV, and the measurement accuracy is at the centimeter level. The altitude information of the UAV can be obtained more accurately on the basis of the altitude information acquisition device in the above embodiment; secondly, a binocular camera is set. 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.

[0071] Specifically, for comprehensive information acquisition equipment, the barometer + radio altimeter + millimeter-wave radar + binocular camera + lidar constitute a high-reliability system for measuring altitude and relative height, with an accuracy of up to millimeter level; the binocular camera + lidar + accelerometer + radio receiving terminal realizes the accurate acquisition of horizontal information. The binocular camera and lidar extract the characteristics of the surrounding terrain environment, match them with the characteristics of the digital map (built-in or pre-built), and obtain their own horizontal position (i.e. longitude and latitude coordinates) in the digital map. The accelerometer estimates the horizontal position of the drone through dead reckoning. The radio receiving terminal receives radio waves of a specific frequency through an antenna, measures the distance to the signal source of the known earth coordinate system, and realizes its own positioning; the binocular camera + magnetic compass + gyroscope realizes the acquisition of heading information.

[0072] The data fusion device 105 is configured to determine the positioning information of the UAV based on at least one sub-altitude information, at least one sub-horizontal information, at least one sub-heading information, and the supplementary position information.

[0073] For example, accurate positioning information can be obtained by preprocessing the corresponding information in the acquired altitude, level, and heading information sets. Specifically, a Kalman filter can be used to process noisy sensor data. By inputting altitude, level, and heading sensor data into the Kalman filter, the data can be optimized and fused to improve the drone's positioning accuracy. The least squares method can also be used to solve the linear equation system. By inputting data from multiple sensors into the least squares algorithm, the drone's position information that is closest to the true value can be obtained.

[0074] In an optional embodiment, the data fusion device includes:

[0075] A height fusion module, configured to determine final height information based on at least one sub-height information and a second height relative to the ground;

[0076] a horizontal fusion module, configured to determine final horizontal information based on at least one sub-level information, environmental information, and first geographic environment information;

[0077] A heading fusion module, configured to determine final heading information based on at least one sub-heading information and environmental information;

[0078] The overall fusion module is used to determine the positioning information based on the final altitude information, the final level information and the final heading information.

[0079] For example, an algorithm or logic is used to combine the information in the altitude information set. For example, this information can be combined with a weighting function to determine the final altitude based on the reliability and accuracy of each input altitude information. The fusion of horizontal information and heading information can both be collected to determine the final information in this way, thereby improving the accuracy of the information.

[0080] On the basis of the above embodiment, the comprehensive information acquisition device is further used to acquire an obstacle information set, which includes obstacle height information, environmental information, and obstacle environment information.

[0081] For example, during the flight of the drone, it is also necessary to accurately obtain the surrounding obstacle information to avoid the drone from colliding with obstacles during the navigation process. Specifically, the corresponding obstacle information can be obtained by using a comprehensive information acquisition device to obtain the obstacle information around the drone.

[0082] On this basis, the obstacle fusion module determines the final obstacle information based on at least one obstacle and environmental information. The millimeter-wave radar, binocular camera, and lidar system can construct the surrounding environment in real time and identify obstacles. The navigation computer then uses obstacle locations to appropriately avoid obstacles when planning routes.

[0083] The system also includes a trajectory planning module, which determines the drone's route based on positioning information, final obstacle information, and pre-acquired target locations. Using a combination of millimeter-wave radar, a binocular camera, and a lidar system, the system constructs a real-time image of the surrounding environment and identifies obstacles. The navigation computer then uses obstacle locations to plan the route and avoid them appropriately.

[0084] The following is a specific example to further illustrate the above embodiments. As shown in Figures 2 and 3, in the absence of a GPS signal, multiple sensors are used to obtain the drone's altitude, horizontal position, and three attitude angles (heading information). The drone's latitude and longitude information is then obtained through an information fusion algorithm. During long-term navigation, due to measurement noise and system errors, the information generated by integrating individual sensor signals can experience significant cumulative errors, leading to complete information distortion. For example, using only accelerometers for position estimation can lead to similar problems. Multiple types of sensors are employed, some of which directly output position and attitude information, others output velocity and acceleration information, some collect local information to improve positioning accuracy, and others collect large-scale, low-precision information. Through information fusion technology, the problem of inability to navigate or low navigation accuracy under conditions of prolonged navigation satellite signal denial is completely resolved, enabling drones to achieve reliable, long-term navigation in navigation satellite signal denial environments.

[0085] This embodiment also provides a method for constructing an automatic naming model for arterial vessels. This method is used to implement the above-mentioned embodiment and optional implementation methods, and will not be repeated here.

[0086] This embodiment provides a method for constructing an automatic arterial vessel naming model, as shown in FIG4 , which is applied to the UAV positioning system under denial conditions in the above embodiment. The method includes:

[0087] Step S401, obtaining a height information set of a UAV, where the height information set includes at least one sub-height information;

[0088] Step S402: obtaining a level information set of the drone, where the level information set includes at least one sub-level information;

[0089] Step S403: Acquire a heading information set of the UAV, where the heading information set includes at least one sub-heading information;

[0090] Step S404, obtaining supplementary location information of the UAV;

[0091] Step S405 : 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.

[0092] The implementation of each of the above steps is the same as that of the above corresponding embodiments and will not be repeated here.

Claims

1. A drone positioning system under denial conditions, characterized in that: The system comprises: A height information acquisition device, used to obtain a height information set of the drone, wherein the height information set includes at least one sub-height information; A level information acquisition device, used to obtain a level information set of the drone, wherein the level information set includes at least one sub-level information; A heading information acquisition device, used to obtain a heading information set of the UAV, wherein the heading information set includes at least one sub-heading information; A comprehensive information acquisition device, used to acquire the supplementary position information of the drone; A data fusion device is used to determine the positioning information of the UAV based on 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 height information collection device comprises: A barometer, used to obtain altitude information of the drone; A radio altimeter is used to obtain first ground altitude information of the UAV.

3. The system according to claim 2, characterized in that The horizontal information acquisition device comprises: An accelerometer, used to obtain acceleration information from a first moment to a current moment, wherein the first moment is a moment when a GPS signal is last obtained; The radio receiving terminal is used to obtain the radio wave frequency sent by the earth, and the acceleration information and the radio wave frequency constitute the horizontal information set.

4. The system according to claim 2 or 3, characterized in that: Heading information collection equipment includes: A gyroscope, used to obtain a first heading angle of the drone; A magnetic compass is used to obtain a relative change of the drone from a first moment to a current moment, wherein the first heading angle and the relative change constitute the heading information set.

5. The system according to claim 4, characterized in that The comprehensive information acquisition device comprises: Millimeter wave radar, used to obtain the second ground altitude; A binocular camera, used to obtain image information, and the image information can obtain environmental information around the drone; The laser radar is used to obtain first geographical environment information corresponding to the drone.

6. The system according to claim 5, characterized in that The data fusion device comprises: a height fusion module, configured to determine final height information according to the at least one sub-height information and the second height above the ground; a horizontal fusion module, configured to determine final horizontal information according to the at least one sub-horizontal information, the environmental information and the first geographic environment information; A heading fusion module, used to determine final heading information according to the at least one sub-heading information and the environmental information; The overall fusion module is used to determine the positioning information according to the final altitude information, the final level information and the final heading information.

7. The system according to claim 6, characterized in that The comprehensive information acquisition device is also used to acquire an obstacle information set, which includes obstacle height information, environmental information, and obstacle environment information.

8. The system according to claim 7, characterized in that The data fusion device also includes: The obstacle fusion module is used to determine 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: The trajectory planning module is used to determine the UAV route according to the positioning information, the final obstacle information and the pre-acquired target position.

10. A method for positioning a drone under denial conditions, characterized in that: Applied to the unmanned aerial vehicle positioning system under denial conditions as described in any one of claims 1 to 9, the method comprising: Acquire the altitude information set of the drone, the altitude information set including at least one sub-altitude information Acquire a level information set of the drone, where the level information set includes at least one sub-level information; Acquire a heading information set of the drone, wherein the heading information set includes at least one sub-heading information; Obtaining supplementary position information of the drone; The positioning information of the UAV is determined 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.

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