Flight and scanning coordination control method for unmanned aerial vehicle patrol

Abstract

The invention discloses a flight and scanning coordination control method for unmanned aerial vehicle patrol, and belongs to the field of unmanned aerial vehicle patrol. The method is divided into a planning stage, a transmission stage and an operation stage. In the planning stage, an unmanned aerial vehicle route and a camera scanning route are planned according to map data, task requirements and flight constraints. In the transmission stage, the ground end uploads the route information and the camera scanning route information through hexadecimal coding, and decodes the camera scanning route information into decimal data as control input. In the working stage, the flight control system controls the unmanned aerial vehicle to fly along a set route and execute hovering operation at a waypoint with a scanning line, and meanwhile, the airborne control terminal controls the scanning process of the camera based on a camera motion control model. Through overall planning and control of the route of the unmanned aerial vehicle and the movement route of the camera, the patrol efficiency of the unmanned aerial vehicle is improved, and an efficient and innovative patrol scheme is provided for scenes such as forest fire prevention, search and disaster relief and regional warning.

Description

Technical Field

[0001] This invention relates to the field of unmanned aerial vehicle (UAV) patrol, and in particular to a flight and scanning coordination control method for UAV patrol. Background Technology

[0002] With the rapid development of drone-related technologies, drones are finding increasingly widespread applications in aerial photography, reconnaissance, and surveying. Patrol is the most basic and primary mission of drones. Fast patrol, accurate identification, and comprehensive search capabilities are the main operational requirements of drone patrol. Therefore, improving patrol efficiency without compromising patrol quality is a research hotspot in the field of drone patrol, especially in scenarios with high real-time requirements such as battlefields, where the need for efficient patrol is even more urgent.

[0003] However, there is a contradiction between patrol efficiency and patrol quality. On the one hand, improving reconnaissance efficiency often requires increasing the flight altitude and speed of drones. On the other hand, the higher the flight altitude, the larger the drone's field of view, the smaller the targets in the aerial images, the lower the target identification accuracy, and the worse the reconnaissance quality.

[0004] The current mainstream approach is to study flight path planning algorithms, which plan the flight path of the drone based on the field of view of the camera on the drone, so that it can complete the field of view coverage of the patrol area in the shortest possible time.

[0005] In recent years, the cameras carried by drones have gradually shifted from single-axis cameras to multi-axis, multi-degree-of-freedom cameras. These cameras can rotate at multiple angles and have a wider field of view. Flight path planning is only effective when the camera's field of view is fixed. When facing multi-degree-of-freedom cameras, the camera's characteristics cannot be fully utilized, resulting in less than satisfactory improvements in patrol efficiency. Summary of the Invention

[0006] In view of this, the present invention provides a flight and scanning coordinated control method for UAV patrol, which improves the patrol efficiency of UAVs by coordinating the control of UAV flight path and camera movement path.

[0007] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0008] A flight and scanning coordinated control method for unmanned aerial vehicle (UAV) patrol includes the following steps:

[0009] (1) Setting up the operation system: The operation system includes UAV, ground software, multi-degree-of-freedom camera and airborne control terminal; among them, UAV is used to perform flight missions; ground software is used to load map information and plan flight routes and scanning routes; multi-degree-of-freedom camera is used to perform scanning actions and transmit reconnaissance images; airborne control terminal is used to control the camera scanning process, and is equipped with camera motion control model to calculate camera attitude, send motion commands, and control the camera to scan along the planned path;

[0010] (2) Planning stage: The ground software plans the UAV route and camera scanning route based on map data, task requirements and flight constraints; wherein, map data is the geographic information of the UAV patrol area, task requirements refer to the information of the area to be reconnoitered, and flight constraints are the UAV's maximum flight altitude and the camera's maximum vertical angle related restrictions.

[0011] (3) Transmission stage: The ground terminal software encodes the UAV flight path information and camera scanning route information into hexadecimal and uploads them to the airborne control terminal via the data link; wherein, the airborne control terminal sends the UAV flight path information directly to the UAV in hexadecimal format, and the airborne control terminal decodes the camera scanning route information into decimal data and performs scanning control during the operation stage;

[0012] (4) Operation phase: The UAV flight control system controls the UAV to fly along the set UAV route and performs hovering operation at waypoints with camera scanning routes. The airborne control terminal determines whether the waypoint to be scanned has been reached. If it has been reached, the camera scanning route information corresponding to the waypoint is sent to the camera motion control model to control the scanning process of the multi-degree-of-freedom camera along the route, thus completing the flight and scanning coordination control for UAV patrol.

[0013] Further, in step (2), the UAV flight path planning refers to drawing a UAV flight path along which the detection range of the multi-degree-of-freedom camera covers all areas to be reconnoitered; wherein, the flight path includes various waypoints, and the waypoint information includes waypoint longitude, waypoint latitude, waypoint altitude above the ground, and hovering time; the camera scanning route planning refers to drawing one or more camera scanning paths along which the camera moves, and its field of view covers the area to be reconnoitered, with each waypoint having at most one camera scanning path, and each camera scanning route including waypoint longitude and latitude and a list of scanning points, wherein the storage information of each scanning point includes scanning point longitude and scanning point latitude;

[0014] The detectable range of the camera refers to the maximum vertical angle assumed to be [value missing]. The drone's flight altitude is Then, the detectable range of the multi-degree-of-freedom camera at this location is a circle centered on the camera's projection onto the ground plane, with... The detectable range of the entire route is the union of the detectable ranges of all waypoints on the route.

[0015] Furthermore, regarding the hexadecimal encoding described in step (3), it is assumed that the UAV flight path includes... For each waypoint, the UAV route information encoding includes the frame header, the number of waypoints, and The longitude, latitude, altitude, hovering time, check bit, and frame end of each waypoint;

[0016] Suppose a camera scanning route includes If there are 10 scan points, the camera scan route information encoding includes the frame header, the total number of scan points, the waypoint number to which the scan line belongs, and so on. The longitude and latitude, check bits, and frame tail corresponding to each scan point;

[0017] The frame header and frame trailer are used to distinguish the boundaries and types of frames; the check bit uses a sum-of-the-parts check method, which is the sum of all bytes except the frame header, frame trailer, and check bit, and is used to detect whether there are transmission errors in the data frame.

[0018] Furthermore, in step (4), the camera scanning route information corresponding to the waypoint is sent to the camera motion control model, and the specific method for controlling the scanning process of the multi-degree-of-freedom camera along the route is as follows:

[0019] (401) Parameter initialization: If a waypoint has a corresponding camera scan route, assume that the current camera scan route includes Each scan point, setting a variable to indicate the scan point. ,make Record the latitude and longitude of the current waypoint of the UAV as ; The current altitude is recorded as The real-time angle of the multi-degree-of-freedom camera is denoted as... , For the real-time true north azimuth angle of a multi-degree-of-freedom camera, For the real-time pitch angle of a multi-degree-of-freedom camera;

[0020] (402) Calculate the first The distance between each scan point and the UAV's current waypoint: Let , Let 1m correspond to latitude and longitude, respectively. , Where 110,940 meters is the distance corresponding to 1 degree of latitude, let... , Then longitude distance Latitude distance The distance between two points projected onto the ground Spatial distance between two points ;

[0021] in, The longitude of the drone's current waypoint. This is the latitude of the drone's current waypoint; For the first Longitude of each scan point For the first The latitude of each scan point;

[0022] (403) Calculate the included angle: Let the first angle be... The angle between the ground projection line connecting the scan points and the current waypoint of the drone and the north-south direction is: , No. The angle between the spatial line connecting each scan point and the current waypoint of the drone and the horizontal plane is: ,but , , , ;

[0023] (404) Calculate the alignment of a multi-degree-of-freedom camera with the first... Angle at each scan point: The true north azimuth range of the multi-degree-of-freedom camera is... The pitch angle range is Point the multi-degree-of-freedom camera at the first The angle at each scan point is denoted as . Based on the current waypoint position of the UAV and the first The relative positions of the scan points are as follows:

[0024] like , ,but , ;

[0025] like , ,but , ;

[0026] like , ,but , ;

[0027] like , ,but , ;

[0028] like , ,but , ;

[0029] like , ,but , ;

[0030] like , ,but , ;

[0031] like , ,but , ;

[0032] like , ,but , ;

[0033] (405) Judgment If the condition is true, proceed to step (406); otherwise, set... Return to execution steps (402)~(404);

[0034] (406) Calculate the total scanning angle of the camera. :

[0035]

[0036] (407) Calculate the camera scan speed constraint for the current camera scan path:

[0037]

[0038] in, The hovering time at the current waypoint, in seconds. The camera scanning speed along the current camera scanning path, expressed in degrees per second;

[0039] (408) Control the scanning process: First, set For multi-degree-of-freedom cameras, from aligning with the first... The first scan point is switched to align with the second. The scanning process of each scan point is calculated, and the horizontal scanning speed during this process is recorded. and vertical scanning speed is , and Camera scanning speed The formulas for calculating the components in the horizontal and vertical directions are as follows:

[0040]

[0041]

[0042] Multi-degree-of-freedom camera scans starting angle Starting from, with The horizontal scanning speed is... Start scanning at the pitch direction scanning speed, with a preset angle error of [value missing]. When the multi-degree-of-freedom camera is in real-time angle From the perspective of the target When the modulus of the difference is within the error range, that is... The scan has ended, so... Repeat step (408) to perform the next scan until... At that time, the current camera scanning route has been completed.

[0043] The advantages of this invention are:

[0044] 1. This invention integrates the planning and control of UAV flight paths and camera scanning routes. During the mission, the UAV not only flies autonomously but also completes autonomous scanning operations, enhancing the fully autonomous capability of the UAV patrol system.

[0045] 2. This invention fully leverages the collaborative capabilities between UAVs and their sensors, effectively improving reconnaissance efficiency without compromising reconnaissance quality, and achieving efficient regional search coverage. Attached Figure Description

[0046] Figure 1 This is an operational system structure and flowchart of a flight and scanning coordinated control method for UAV patrol according to an embodiment of the present invention.

[0047] Figure 2 This is a schematic diagram of map data and task requirements in an embodiment of the present invention.

[0048] Figure 3 This is a schematic diagram of the camera's detectable range in an embodiment of the present invention.

[0049] Figure 4 This is a schematic diagram of the coordination planning results between the UAV flight path and the camera scanning route in an embodiment of the present invention.

[0050] Figure 5 This is a schematic diagram of the UAV route information encoding structure in an embodiment of the present invention.

[0051] Figure 6 This is a schematic diagram of the camera scanning route information encoding structure in an embodiment of the present invention. Detailed Implementation

[0052] The technical solution of the present invention will be further described below with reference to the accompanying drawings and embodiments. Obviously, these descriptions are only some embodiments of the present invention, and not all embodiments. All other embodiments obtained by those skilled in the art based on the following embodiments without creative effort are within the protection scope of the present invention.

[0053] A method for coordinated flight and scanning control for unmanned aerial vehicle (UAV) patrols, the method's operating system and process are as follows: Figure 1 As shown, the operating system includes a drone, ground-based software, multi-degree-of-freedom cameras, and an airborne control terminal. The specific process includes:

[0054] (1) During the planning phase, the operator plans the waypoints and camera scanning routes of the UAV in the ground software based on map data, task requirements and flight constraints, and stores the planning information in the prescribed format.

[0055] (2) During the transmission phase, the ground-based software encodes the flight path planning information and the camera scanning route planning information into hexadecimal and uploads them via the data link. The flight path encoding information is transmitted to the UAV flight control system, and the camera scanning route encoding information is transmitted to the airborne control terminal for decoding.

[0056] (3) During the operation phase, the UAV flight control system controls the UAV to fly along the set route and perform hovering operations at waypoints with scan lines. At the hovering waypoint, the airborne control terminal transmits the scan line information to the camera motion model and controls the camera to scan along the specified route, thereby realizing coordinated control of the UAV's flight and scanning.

[0057] In step (1), see Figure 2 First, the map data, mission requirements, and flight constraints are defined, assuming the map size is [missing information]. The mission requirement is to scan roads 1 and 2, with a flight constraint of a maximum flight altitude of [missing information]. The maximum vertical angle is .

[0058] Secondly, calculate the maximum detectable range of the camera under the constraints. For example... Figure 3 As shown, the detection radius of the drone The detection range is maximized when the maximum altitude and maximum vertical angle are reached within the flight constraints. Figure 2 Under the defined map and constraints, the maximum detection radius is .

[0059] Based on the maximum detection range, hovering waypoints are inserted to generate the UAV flight path. The requirement is that the union of the detectable ranges of all hovering waypoints covers the entire area to be reconnoitered. In this example, the planning is as follows: Figure 4The route shown stores the route planning information as a waypoint array. Each waypoint includes longitude, latitude, altitude, and hovering time, among which... Starting from, As the endpoint, , Hovering waypoint. , The detection range can cover both Road 1 and Road 2, and road scanning is performed at these two points.

[0060] At the waypoint , Draw the corresponding camera scan path and ,like Figure 4 As shown by the dashed lines, the planning information for each scan line consists of the latitude and longitude of the corresponding waypoint and a list of scan points. The stored information for each scan point includes its longitude and latitude. (The text then repeats the information about the scan line.) For example, it includes three scan points. Each scan point contains the latitude and longitude information of that point.

[0061] In step (2), the UAV flight path information is encoded as follows: A hexadecimal number of bytes, including frame header, number of waypoints, waypoint longitude, waypoint latitude, waypoint altitude, hover time, check bit, and frame trailer. For example... Figure 5 As shown, the frame header is 2 bytes, the number of waypoints is 2 bytes, the checksum is 1 byte, the frame tail is 1 byte, and for each waypoint, the longitude, latitude, altitude, and hovering time are each 4 bytes.

[0062] The frame header and frame trailer are fixed values. The frame header is set to 0x0A and 0xA1, and the frame trailer is set to 0xAA. The checksum is calculated using a summation check method, which is the sum of all bytes except the frame header, frame trailer, and checksum.

[0063] Camera scanning route information is encoded as A hexadecimal number of bytes, including frame header, total number of scan points, waypoint number of scan line, longitude of scan point, latitude of scan point, check bit, and frame tail. For example... Figure 6 As shown, the frame header is 2 bytes, the number of scan points is 2 bytes, the waypoint number is 2 bytes, the check bit is 1 byte, the frame tail is 1 byte, and for each scan point, the longitude and latitude of the scan point are 4 bytes each.

[0064] The frame header and trailer are fixed values: the frame header is set to 0x0A and 0xA2, and the frame trailer is set to 0xAA. The checksum also uses a checksum method. The airborne control terminal distinguishes the frame boundaries and type through the frame header and trailer, and detects whether there are transmission errors in the data frame through the checksum.

[0065] After encoding at the ground end, the hexadecimal encoded values ​​are uploaded via data link based on the UDP communication protocol. Among them, the flight path encoding information is uploaded to the UAV flight controller, and the camera scan route encoding information is uploaded to the airborne control terminal on the UAV. The airborne control terminal distinguishes the boundaries and types of frames by frame headers and frame tails, detects whether there are transmission errors in the data frames by check bits, and parses the encoded data into decimal values ​​for storage.

[0066] In step (3), first determine whether the UAV has reached the waypoint, and set the current position coordinates of the UAV. Waypoint coordinates Error value That is, when the difference between the current position and the waypoint position of the drone is within Within a certain timeframe, the drone is considered to have reached the waypoint, calculated using the following formula:

[0067]

[0068] After the drone arrives at the waypoint, it determines whether there is a scan line at the waypoint. If the scan line exists, the drone performs a hovering operation, transmits the scan line information to the camera motion model, and controls the camera to scan along the specified route.

[0069] like Figure 4 As shown, the drone is at the hovering point. For the line Perform a scan, set The hovering time of the point is 30 seconds, and the current coordinates of the drone are... ,high Scan point exist Northwest direction, coordinates are Scan point exist Northeast direction, coordinates are Scan point exist Southeast direction, coordinates are .

[0070] Calculate scan points To the current location of the drone The distance. For Its longitude distance Latitude distance , Earth projection distance , spatial distance

[0071] calculate The angle between the projection line onto the Earth and the north-south direction is denoted as . ,but Then calculate The angle between the line connecting the two spaces and the horizontal plane is denoted as . ,but .

[0072] Calculate scan points The corresponding camera angle is set to . , .but ,

[0073] Similarly, scan points , value replacement By repeating the above steps, the scan points can be obtained. Corresponding camera angle Scan point Corresponding camera angle .

[0074] Calculate the scanning line The total angle of camera scanning, , , Substitute into the formula achievable According to the hovering point The hover time set by the point can be used to obtain the scan speed constraint. .

[0075] Control the camera scanning process and set the scanning speed according to the above-mentioned scanning speed constraints. 5 The camera from the angle Movement to angle The horizontal scanning speed can be calculated as follows: Pitch speed Make the camera... The velocity is in the horizontal direction. For pitch velocity, from... Sweep towards Let the angle error be... Update the camera's current angle in real time. Then when This segment of the scan ends, meaning the scan from the road is now complete. Click Road segment scanning between points. Set the scan start and end points to... and Repeat this process to complete the road. Click The system scans road segments between points to scan the entire route.

[0076] The above embodiments are merely specific implementations of the present invention, but the scope of protection of the present invention is not limited thereto. Those skilled in the art should understand that any modifications or equivalent substitutions to the specific implementations of the present invention that do not depart from the spirit and scope of the present invention should be covered within the scope of protection of the claims of the present invention.

Claims

1. A flight and scanning coordinated control method for unmanned aerial vehicle (UAV) patrol, characterized in that, Includes the following steps: (1) Setting up the operation system: The operation system includes UAV, ground software, multi-degree-of-freedom camera and airborne control terminal; among them, UAV is used to perform flight missions; ground software is used to load map information and plan flight routes and scanning routes; multi-degree-of-freedom camera is used to perform scanning actions and transmit reconnaissance images; airborne control terminal is used to control the camera scanning process, and is equipped with camera motion control model to calculate camera attitude, send motion commands, and control the camera to scan along the planned path; (2) Planning stage: The ground software plans the UAV route and camera scanning route based on map data, task requirements and flight constraints; wherein, map data is the geographic information of the UAV patrol area, task requirements refer to the information of the area to be reconnoitered, and flight constraints are the UAV's maximum flight altitude and the camera's maximum vertical angle related restrictions. (3) Transmission stage: The ground terminal software encodes the UAV flight path information and camera scanning route information into hexadecimal and uploads them to the airborne control terminal via the data link; wherein, the airborne control terminal sends the UAV flight path information directly to the UAV in hexadecimal format, and the airborne control terminal decodes the camera scanning route information into decimal data and performs scanning control during the operation stage; (4) Operation phase: The UAV flight control system controls the UAV to fly along the set UAV route and performs hovering operation at waypoints with camera scanning routes. The airborne control terminal determines whether the waypoint to be scanned has been reached. If it has been reached, the camera scanning route information corresponding to the waypoint is sent to the camera motion control model to control the scanning process of the multi-degree-of-freedom camera along the route, thus completing the flight and scanning coordination control for UAV patrol.

2. The flight and scanning coordinated control method for UAV patrol according to claim 1, characterized in that, In step (2), the UAV flight path planning refers to drawing a UAV flight path along which the detection range of the multi-degree-of-freedom camera covers all areas to be reconnoitered; the flight path includes waypoints, and the waypoint information includes waypoint longitude, waypoint latitude, waypoint altitude above the ground, and hovering time; the camera scanning route planning refers to drawing one or more camera scanning paths along which the camera moves, and its field of view covers the area to be reconnoitered. Each waypoint has at most one camera scanning path, and each camera scanning route includes waypoint longitude and latitude and a list of scanning points, wherein the stored information of each scanning point includes scanning point longitude and scanning point latitude; The detectable range of the camera refers to the maximum vertical angle assumed to be [value missing]. The drone's flight altitude is Then, the detectable range of the multi-degree-of-freedom camera at this location is a circle centered on the camera's projection onto the ground plane, with... The detectable range of the entire route is the union of the detectable ranges of all waypoints on the route.

3. The flight and scanning coordinated control method for UAV patrol according to claim 1, characterized in that, Regarding the hexadecimal encoding mentioned in step (3), assuming the UAV flight path includes... For each waypoint, the UAV route information encoding includes the frame header, the number of waypoints, and The longitude, latitude, altitude, hovering time, check bit, and frame end of each waypoint; Suppose a camera scanning route includes If there are 10 scan points, the camera scan route information encoding includes the frame header, the total number of scan points, the waypoint number to which the scan line belongs, and so on. The longitude and latitude, check bits, and frame tail corresponding to each scan point; The frame header and frame trailer are used to distinguish the boundaries and types of frames; the check bit uses a sum-of-the-parts check method, which is the sum of all bytes except the frame header, frame trailer, and check bit, and is used to detect whether there are transmission errors in the data frame.

4. The flight and scanning coordinated control method for UAV patrol according to claim 1, characterized in that, In step (4), the camera scanning route information corresponding to the waypoint is sent to the camera motion control model. The specific method for controlling the scanning process of the multi-degree-of-freedom camera along the route is as follows: (401) Parameter initialization: If a waypoint has a corresponding camera scan route, assume that the current camera scan route includes Each scan point, setting a variable to indicate the scan point. ,make ; Record the latitude and longitude of the drone's current waypoint as... The current altitude is recorded as The real-time angle of the multi-degree-of-freedom camera is denoted as... , For the real-time true north azimuth angle of a multi-degree-of-freedom camera, For the real-time pitch angle of a multi-degree-of-freedom camera; (402) Calculate the first The distance between each scan point and the UAV's current waypoint: Let , Let 1m correspond to latitude and longitude, respectively. , Where 110,940 meters is the distance corresponding to 1 degree of latitude, let... , Then longitude distance Latitude distance The distance between two points projected onto the ground Spatial distance between two points ; in, The longitude of the drone's current waypoint. This is the latitude of the drone's current waypoint; For the first Longitude of each scan point For the first The latitude of each scan point; (403) Calculate the included angle: Let the first angle be... The angle between the ground projection line connecting the scan points and the current waypoint of the drone and the north-south direction is: , No. The angle between the spatial line connecting each scan point and the current waypoint of the drone and the horizontal plane is: ,but , , , ; (404) Calculate the alignment of a multi-degree-of-freedom camera with the first... Angle at each scan point: The true north azimuth range of the multi-degree-of-freedom camera is... The pitch angle range is Point the multi-degree-of-freedom camera at the first The angle at each scan point is denoted as . Based on the current waypoint position of the UAV and the first The relative positions of the scan points are as follows: like , ,but , ; like , ,but , ; like , ,but , ; like , ,but , ; like , ,but , ; like , ,but , ; like , ,but , ; like , ,but , ; like , ,but , ; (405) Judgment If the condition is true, proceed to step (406); otherwise, set... Return to execution steps (402)~(404); (406) Calculate the total scanning angle of the camera. : ； (407) Calculate the camera scan speed constraint for the current camera scan path: ； in, The hovering time at the current waypoint, in seconds. The camera scanning speed along the current camera scanning path, expressed in degrees per second; (408) Control the scanning process: First, set For multi-degree-of-freedom cameras, from aligning with the first... The first scan point is switched to align with the second. The scanning process of each scan point is calculated, and the horizontal scanning speed during this process is recorded. and vertical scanning speed is , and Camera scanning speed The formulas for calculating the components in the horizontal and vertical directions are as follows: ； ； Multi-degree-of-freedom camera scans starting angle Starting from, with The horizontal scanning speed is... Start scanning at the pitch direction scanning speed, with a preset angle error of [value missing]. When the multi-degree-of-freedom camera is in real-time angle From the perspective of the target When the modulus of the difference is within the error range, that is... The scan has ended, so... Repeat step (408) to perform the next scan until... At that time, the current camera scanning route has been completed.

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