An electro-optical automatic joint reconnaissance method applicable to fixed-wing UAVs

Abstract

This invention specifically relates to an electro-optical automatic reconnaissance method applicable to fixed-wing unmanned aerial vehicles (UAVs), comprising: receiving a mission package from a higher-level command system containing a reconnaissance area and a set of multiple target points to be reconnaissance; determining a serpentine fixed-point flight path and a local rectangular area based on the reconnaissance area; classifying the set of multiple target points to be reconnaissance to obtain a detailed waypoint set; arranging the serpentine fixed-point flight path and the detailed waypoint set to generate a reconnaissance flight path with the shortest travel distance for the UAV from its current position through the arranged waypoints; controlling the UAV to fly autonomously along the reconnaissance flight path, automatically activating electro-optical linkage based on the positional relationship between the UAV and the local rectangular area or each detailed waypoint, thereby achieving automatic reconnaissance. This method reduces the operational burden on personnel, improves the identification probability and reconnaissance efficiency, and enhances the flexibility of UAV tactical applications.

Description

Technical Field

[0001] This invention relates to the field of unmanned aerial vehicle (UAV) technology, and more specifically to an electro-optical automatic linkage reconnaissance method applicable to fixed-wing UAVs. Background Technology

[0002] With the development of UAV reconnaissance technology, using UAVs for intelligence gathering has become an important supplement and enhancement to reconnaissance satellites and manned reconnaissance aircraft. Compared with reconnaissance satellites, UAVs have advantages such as lower cost, more flexible control of reconnaissance areas, and higher target resolution. Compared with manned reconnaissance aircraft, they have the ability to conduct long-term surveillance of specific areas, high-precision tracking of specific routes, and repetitive execution of specific missions, and do not need to consider issues such as pilot casualties. UAV reconnaissance has become an important aerial reconnaissance equipment.

[0003] Currently, UAV reconnaissance still requires operators to monitor in real-time via data links, resulting in limited autonomous reconnaissance capabilities. When the UAV system receives mission packages from external sources, such as general reconnaissance of the area to be reconnaissance and detailed reconnaissance of multiple target points, it typically plans a flight path based on the experience of the commanding officer. The mission is then completed through cooperation between the flight control operator and the task control operator, especially the task control operator, who needs strong optoelectronic operation skills. However, the varying experience and abilities of personnel greatly increase the likelihood of being time-consuming and laborious, and potentially missing targets, leading to mission failure. If the UAV data link is interrupted, the operators are unable to continue reconnaissance. In the rapidly changing battlefield environment, this can easily lead to missed opportunities. Therefore, there is an urgent need to invent an automatic photoelectric linkage reconnaissance system that can quickly plan an automatic reconnaissance route when receiving externally issued task packages for general surveying of the area to be reconnaissance and detailed surveying of multiple target points. Furthermore, during the flight of the UAV along the reconnaissance route, the photoelectric platform works in conjunction to automatically conduct general surveys of the area to be reconnaissance and detailed surveys of multiple target points, effectively improving the identification probability and reconnaissance efficiency, and reducing the burden on personnel. Even if the UAV's data link is interrupted, as long as the planning has been completed, the UAV can still perform the predetermined reconnaissance mission normally. Summary of the Invention

[0004] When an unmanned aerial vehicle (UAV) system receives a mission package containing the area to be reconnoitered and a set of multiple targets from an external source, this invention provides an electro-optical automatic linkage reconnaissance method suitable for fixed-wing UAVs. This method aims to reduce the operational burden on personnel, improve identification probability and reconnaissance efficiency, and enhance the flexibility of UAV tactical applications, in order to avoid the reconnaissance process relying entirely on human experience and operational capabilities, or being unable to continue the mission due to data link interruptions.

[0005] Other features and advantages of the invention will become apparent from the following detailed description, or may be learned in part by practice of the invention.

[0006] According to a first aspect of the present invention, an electro-optical automatic linkage reconnaissance method suitable for fixed-wing unmanned aerial vehicles is provided, the method comprising:

[0007] Receive a mission package from the superior command system containing the area to be reconnoitered and a set of multiple targets to be reconnoitered;

[0008] Based on the area to be reconnoitered, a serpentine fixed-point route and the local rectangular area reconnoitered by the UAV on each long side of the serpentine fixed-point route are determined.

[0009] The set of multi-target points to be reconnoitered is categorized to obtain a set of detailed waypoints containing attribute lists;

[0010] Arrange the serpentine fixed-point route and the detailed reconnaissance waypoint set to generate a reconnaissance route with the shortest travel distance for the UAV to pass through the arranged waypoints sequentially from the current position.

[0011] The drone is controlled to fly autonomously along the reconnaissance route. Based on the positional relationship between the drone and the local rectangular area or each detailed reconnaissance waypoint, photoelectric linkage is automatically activated to achieve automatic reconnaissance.

[0012] In some exemplary embodiments, when the area to be detected is irregularly shaped, the method further includes:

[0013] The area to be detected is automatically converted into a rectangular area that minimizes the coverage of this irregular area.

[0014] Based on the rectangular area to be investigated, a serpentine fixed-point route is determined.

[0015] In some exemplary embodiments, automatically converting the area to be reconnoitered into a minimum rectangular area to be reconnoitered that covers the irregular area includes:

[0016] The maximum and minimum longitude and latitude of the irregular area to be investigated are calculated by rotating the coordinate system from 0 to 360 degrees. The maximum and minimum longitude and latitude are combined in pairs to obtain a rectangular area. The area of ​​the rectangle under different rotation angles is calculated. The coordinates of the points in the rectangular area with the smallest area are converted into the coordinates of the points in the xoy coordinate system to obtain the rectangular area to be investigated.

[0017] In some exemplary embodiments, determining the serpentine fixed-point route based on the rectangular area to be detected includes:

[0018] The angle of the serpentine fixed-point route is the angle of the rectangular area to be reconnoitered; the center point position is the center point position of the rectangular area to be reconnoitered; the length is the length of the rectangular area to be reconnoitered plus the interval of the serpentine fixed-point route; the number of long side segments is the result of dividing the width of the rectangular area to be reconnoitered by the interval of the serpentine fixed-point route and rounding it up; the turning radius is half of the interval of the serpentine fixed-point route.

[0019] In some exemplary embodiments, the method for calculating the interval of the serpentine fixed-point route includes:

[0020] Calculate the recognition distance of the photoelectric device;

[0021] Calculate the field of view of the optoelectronic device;

[0022] Based on the recognition distance of the optoelectronic device, the field of view of the optoelectronic device, and the height of the UAV flight field, the width of the local rectangle that the optoelectronic device can recognize in the vertical direction of the UAV's long side flight path is calculated, i.e., the interval of the serpentine fixed-point flight path.

[0023] In some exemplary embodiments, the set of multiple targets to be reconnoitered is categorized to obtain a detailed waypoint set, including:

[0024] Calculate the distance between each pair of the target points in the set to be detected, and determine whether they are close to each other. If the distance is less than the proximity distance, they are considered close to each other; otherwise, they are not close to each other. The proximity distance is equal to the diameter of the minimum fixed-point hovering of the UAV.

[0025] Obtain the neighboring points of each target point to be scouted, and start merging from the target point with the most neighboring points. That is, take the target point with the most neighboring points as the waypoint of the scouted route, record the number of neighboring points it has, and mark these neighboring points respectively.

[0026] Merge the remaining target points that have the second most or the same number of adjacent target points as the target point with the most adjacent points. Before merging, first determine whether the target point has been marked as a waypoint or adjacent point of the reconnaissance route. If so, skip the point. Otherwise, mark the point as a waypoint of the reconnaissance route, record the number of adjacent points it has, and mark these adjacent points respectively.

[0027] After removing duplicate neighboring points of the reconnaissance route waypoint, a list of attributes of the target point to be reconnoitered is obtained, including whether it is a waypoint or a neighboring point of the reconnaissance route, the number and sequence of neighboring points when it is a waypoint, and the type parameter of the waypoint.

[0028] In some exemplary embodiments, arranging the serpentine fixed-point route and the detailed waypoint set includes:

[0029] When the number of waypoints included in the serpentine fixed-point route and the number of waypoints in the detailed reconnaissance set are less than the threshold, the exhaustive method is used to perform a full permutation of the waypoints of the reconnaissance route, calculate the flight distance of the UAV from the current position through each permutation of waypoints, and generate the final reconnaissance route by the waypoint permutation of the shortest flight distance obtained.

[0030] When the number of waypoints included in the serpentine fixed-point route and the number of waypoints in the detailed reconnaissance set are greater than or equal to the threshold, the Dijkstra algorithm is used to calculate the shortest flight distance for the UAV to pass through all waypoints sequentially from the current position, and the final reconnaissance route is generated by arranging the waypoints with the obtained shortest flight distances.

[0031] In some exemplary embodiments, the automatic activation of photoelectric linkage based on the positional relationship between the UAV and the local rectangular area or each detailed waypoint includes:

[0032] When the UAV flies along a serpentine fixed-point flight path, the system determines whether it has entered a local rectangular area to activate the electro-optical linkage. The electro-optical equipment automatically adjusts to move the turntable under a wide field of view using geographic guidance, sequentially pointing towards the calculated area to achieve area surveying. When entry into a local rectangular area is detected, the system first calculates the target point set requiring geographic guidance within that area based on the coordinates of four points within the local rectangular area. Then, as the UAV flies along the fixed-point flight path and enters the local rectangular area, the electro-optical platform activates geographic guidance. The geographic guidance method aligns the longer side of the field of view with the direction of the UAV's ground speed, guiding the coordinate points sequentially as follows: The calculated set of geographic guidance target points enables the photoelectric system to sequentially point to the optical television field area where the geographic guidance target point is located to achieve regional reconnaissance. When the UAV leaves the straight section of the serpentine flight path and enters the turning section, that is, when it leaves the local rectangular area, the photoelectric linkage stops. When the UAV enters the next local rectangular area again, the above process is repeated until the entire rectangular area is reconnoitered. During the reconnaissance process, the time interval of the geographic guidance target point is adjusted according to the real-time ground speed of the UAV to achieve synchronization between the UAV's movement and the photoelectric system's lateral back-and-forth geographic guidance. That is, when the UAV travels twice the long side field of view distance of the photoelectric system, the photoelectric system simultaneously completes one cycle of lateral back-and-forth geographic guidance.

[0033] When the waypoint the UAV flies to is a detailed reconnaissance waypoint, the electro-optical linkage is activated by determining whether the UAV has entered an area with the waypoint as the center and the distance of the UAV's minimum fixed-point hovering diameter as the radius. The electro-optical equipment is automatically adjusted to move the turntable in a small field of view through geographic guidance, pointing to the target points to be reconnoitered in sequence to achieve detailed reconnaissance of multiple target points. After the linkage is activated, the electro-optical equipment is automatically guided to the target point coordinates, i.e., the coordinates of the nearby points carried by this waypoint, until all nearby points and targets at the location of this waypoint are reconnoitered. Then the electro-optical linkage is stopped and the UAV automatically switches to the next waypoint. After the conditions for activating the electro-optical linkage are met, the above process is repeated until all reconnaissance tasks are completed.

[0034] According to a second aspect of the present invention, a storage medium is provided having a computer program stored thereon, which, when executed by a processor, implements the electro-optical automatic linkage reconnaissance method applicable to fixed-wing unmanned aerial vehicles described in the first aspect.

[0035] According to a third aspect of the present invention, a computer program product is provided, on which a computer program is stored, wherein when the computer program is executed by a processor, the electro-optical automatic linkage reconnaissance method applicable to fixed-wing unmanned aerial vehicles described in the first aspect is implemented.

[0036] This invention provides an automatic electro-optical linkage reconnaissance method suitable for fixed-wing UAVs. Compared with previous methods that relied on manual planning of reconnaissance routes and control of UAV flight in coordination with the operation of an electro-optical platform to complete tasks such as general surveying of the area to be reconnaissance and detailed surveying of multiple target points, this method can quickly plan an automatic reconnaissance route that is coupled with the identification capabilities of the electro-optical platform and closely linked to the area to be reconnaissance and the multiple target points based on information about the area to be reconnaissance, information about multiple target points, identification parameters of the electro-optical platform, and altitude of the operating field. When the UAV is flying along the reconnaissance route, the electro-optical platform can also automatically coordinate to conduct general surveys of the area to be reconnaissance and detailed surveys of multiple target points based on the position of the UAV on the route, effectively improving the identification probability and reconnaissance efficiency, and greatly reducing the burden on personnel.

[0037] In terms of UAV tactical applications, operators can choose to use a silent data link to reduce the probability of being detected by the enemy, or if the telemetry and control link is temporarily lost due to enemy interference, as long as the planning is completed using this method, the UAV can still continue to perform electro-optical automatic reconnaissance on the planned route to complete the reconnaissance mission. After the data link is restored, the historical reconnaissance records are transmitted and then the intelligence is interpreted, which improves the flexibility of UAV tactical applications.

[0038] It should be understood that the above general description and the following detailed description are exemplary and explanatory only, and are not intended to limit the invention. Attached Figure Description

[0039] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the invention and, together with the description, serve to explain the principles of the invention. It is obvious that the drawings described below are merely some embodiments of the invention, and those skilled in the art can obtain other drawings based on these drawings without any inventive effort.

[0040] Figure 1 A schematic diagram illustrating the calculation of the area to be investigated using the coordinate rotation method is shown below.

[0041] Figure 2 The diagram illustrates the area to be reconnaissance and the "serpentine" fixed-point survey route.

[0042] Figure 3 A schematic diagram of a partial rectangular area within the rectangular area to be investigated is shown.

[0043] Figure 4 This diagram schematically illustrates the reconnaissance field of view of a drone.

[0044] Figure 5 A schematic diagram showing a partial detailed view of the UAV's reconnaissance field of view;

[0045] Figure 6 A schematic diagram of the target point set to be detected is shown.

[0046] Figure 7 A schematic diagram of the reconnaissance route is shown.

[0047] Figure 8 The flowchart of the photoelectric automatic linkage reconnaissance method is shown schematically. Detailed Implementation

[0048] Exemplary embodiments will now be described more fully with reference to the accompanying drawings. However, these exemplary embodiments can be implemented in many forms and should not be construed as limited to the examples set forth herein; rather, they are provided so that the invention will be more comprehensive and complete, and will fully convey the concept of the exemplary embodiments to those skilled in the art. The described features, structures, or characteristics may be combined in any suitable manner in one or more embodiments.

[0049] Furthermore, the accompanying drawings are merely illustrative of the invention and are not necessarily drawn to scale. The same reference numerals in the drawings denote the same or similar parts, and therefore repeated descriptions of them will be omitted. Some block diagrams shown in the drawings are functional entities and do not necessarily correspond to physically or logically independent entities. These functional entities can be implemented in software, in one or more hardware modules or integrated circuits, or in different network and / or processor devices and / or microcontroller devices.

[0050] This example embodiment provides an electro-optical automatic joint reconnaissance method suitable for fixed-wing UAVs. Based on information about the area to be reconnoitered, multi-target point set information, electro-optical platform identification parameters, and operational altitude, it can quickly plan an automatic reconnaissance route that is coupled with the electro-optical platform's identification capabilities and closely linked to the area to be reconnoitered and the multi-target point set. While the UAV is flying along the reconnaissance route, the electro-optical platform can also automatically coordinate to achieve both a general survey of the area to be reconnoitered and a detailed survey of the multi-target point set, depending on the UAV's position on the route. (Reference) Figure 8 As shown, the specific steps include:

[0051] Step 1: When the UAV system receives the externally issued task package for general reconnaissance of the area to be reconnaissance and detailed reconnaissance of multiple target point sets, since the area to be reconnaissance may be irregular in shape, it first automatically converts the area to be reconnaissance into a rectangular area that minimizes the size of this irregular area, facilitating automatic planning of reconnaissance routes and division of reconnaissance areas. The conversion method is as follows: Using the coordinate rotation method, the maximum and minimum longitudes and latitudes of the irregular area to be reconnaissance are calculated under coordinate system rotations from 0 to 360 degrees. The maximum and minimum longitudes and latitudes are combined in pairs to obtain a rectangular area. The area of ​​the rectangle under different rotation angles is calculated, and after comparing the areas, the coordinates of the points in the rectangular area with the smallest area are finally obtained. These coordinates are then converted to the point coordinates in the xoy coordinate system to obtain the rectangular area to be reconnaissance.

[0052] Step 2: Based on the rectangular area information obtained in Step 1, automatically generate a "snake-like" fixed-point flight path that can completely cover the entire area for electro-optical reconnaissance. The angle of the "snake-like" fixed-point flight path is the same as the angle of the rectangular area, both being ag. The center point is the same as the center point of the rectangular area. The length is the length of the rectangular area l plus the interval d of the "snake-like" fixed-point flight path. The number of segments on the longer side is the width w of the rectangular area divided by the interval d of the "snake-like" fixed-point flight path, rounded up. The turning radius r of the "snake-like" fixed-point flight path is half of the interval d. The interval d depends on the maximum field of view of the electro-optical platform carried by the UAV. The recognition capability ensures that when the UAV flies along the long side of the "serpentine" fixed-point route, the photoelectric platform can identify local targets at half the distance of the "serpentine" fixed-point route in the left and right vertical directions of the UAV's flight path. That is, the width of the local area is equal to the serpentine interval with a distance of d. This ensures that the UAV flies back and forth along the adjacent long sides of the "serpentine" fixed-point route without missing any areas. Together, they cover the rectangular area to be detected. At the same time, the platform calculates the coordinates of four points of the local rectangular area detected by the UAV on each long side of the "serpentine" route. The length of the local rectangular area is the length of the rectangular area to be detected, and the width is the interval d of the "serpentine" fixed-point route.

[0053] The intervals of a "serpentine" fixed-point flight path can be calculated using the following steps:

[0054] Step 2-1: Calculate the recognition distance of the photoelectric device, using the following formula:

[0055]

[0056] Where L is the recognition distance of the photoelectric device, km; h is the size of the target to be recognized, m; n is the number of line pairs, determined according to the minimum number of line pairs that the photoelectric device can recognize; P is the pixel size, μm; and f is the focal length of the optical lens in the wide field of view, mm.

[0057] Step 2-2: Calculate the field of view of the photoelectric device, using the following formula:

[0058]

[0059] Where α is the field of view angle, which is determined by the number of pixels on the long and short sides of the field of view, in radians; P is the pixel size, in μm; f is the focal length of the optical lens, in mm; and N is the number of pixels in the field of view direction.

[0060] Steps 2-3: Calculate the width of the local rectangle that the optoelectronic device can identify in the vertical direction of the UAV's long-side flight path, i.e., the "snake" interval d, as shown in the following formula:

[0061]

[0062] Where d is the width of the local rectangle that the optoelectronic device can identify in the vertical direction of the UAV's long side flight path, in km; H is the height of the UAV's flight field, in km; L is the identification distance of the optoelectronic device, in km; α is the field of view angle of the optoelectronic device's short side, in radians; to ensure that the UAV can identify ground targets, the height of the UAV's reconnaissance field H must be less than the identification distance L.

[0063] Step 3: Categorize the set of multiple targets to be reconnoitered within the mission package. The goal of categorization is to ensure that when the UAV flies along the automatically generated reconnaissance route, it can reconnoiter all the multiple targets to be reconnoitered, while reducing the number of waypoints for the UAV, ultimately achieving the goal of reducing the total flight distance and improving reconnaissance efficiency. The categorization method is as follows:

[0064] Step 3-1: Calculate the distance between each pair of target points in the set to be reconnoitered, and determine whether they are close to each other. If the distance is less than the proximity distance, they are considered close to each other; otherwise, they are not close to each other. The proximity distance is equal to the diameter of the minimum fixed-point hovering of the UAV.

[0065] Step 3-2: Obtain the neighboring points of each target point to be scouted. Start merging from the target point to be scouted with the most neighboring points. That is, take the target point to be scouted with the most neighboring points as the waypoint of the scouted route, record the number of neighboring points it has, and mark these neighboring points respectively.

[0066] Step 3-3: Start merging from the remaining target points that have the second most or the same number of adjacent target points as the target point with the most adjacent points. Before merging, first determine whether the target point to be scouted has been marked as a waypoint or adjacent point of the scouted route. If so, skip the point. Otherwise, mark the point as a waypoint of the scouted route, record the number of adjacent points it has, and mark these adjacent points respectively.

[0067] Step 3-4: Repeat step 3-3 above until all target points to be scouted are marked. At this point, you can get a list of the attributes of the target points to be scouted, including whether they are waypoints or nearby points of the scouted route, and the number and sequence number of nearby points when they are waypoints. However, after this step, there may be cases where the same nearby points are duplicated.

[0068] Steps 3-5: Remove duplicate neighboring points owned by the reconnaissance route waypoint. The removal method is to skip the recorded neighboring points and the processed points, start from the reconnaissance route waypoint with the most neighboring points or the other target points with the same number of neighboring points, record the serial numbers of the unrecorded neighboring points it has, delete the recorded neighboring points, and mark this reconnaissance route waypoint as a processed point.

[0069] Steps 3-6: Repeat steps 3-5 until all reconnaissance waypoints have been processed, resulting in a final attribute list of target points to be reconnoitered. This attribute list includes: whether it is a waypoint or a nearby point on a reconnaissance route; the number and sequence of nearby points when used as a waypoint; and the waypoint type parameter. To improve reconnaissance efficiency and stability, there are two waypoint types: through point or UAV minimum diameter disc fixed-point route. The waypoint type is mainly determined by the number of nearby points, cruising speed, UAV minimum disc diameter, and the planned dwell time for each target point. The determination strategy is as follows: Calculate the time t1 for the UAV to circle once based on the cruising speed and UAV minimum disc diameter; obtain the total reconnaissance time t2 for this waypoint based on the planned dwell time for each target point and the number of nearby points. If t2 / t1 ≤ 0.5, the waypoint type is set to through point; if t2 / t1 > 0.5, the waypoint type is set to disc, and the number of circles is t2 / t1 rounded up.

[0070] Step 4: Arrange the coordinates of all waypoints in the target point attribute list obtained in Step 3 and the coordinates of the "serpentine" fixed-point route obtained in Step 2 to automatically generate the final reconnaissance route. The goal of the reconnaissance route is to minimize the distance traveled by the UAV from its current position through the above waypoints. The method for automatically generating the reconnaissance route is as follows:

[0071] Case 1: When the number of waypoints for the reconnaissance route is less than 10, the "exhaustive method" is used to perform a full permutation of the waypoints for the reconnaissance route. The flight distance of the UAV from the current position through each permutation of waypoints is calculated. The final reconnaissance route is generated by the waypoint permutation with the shortest flight distance. In this case, the optimal flight distance can be achieved when the number of waypoints is small, without consuming computer computing power.

[0072] Scenario 2: When the number of waypoints on the reconnaissance route is greater than or equal to 10, the "exhaustive search method" consumes a lot of computing power. To improve computing efficiency, the "Dijkstra algorithm" is selected to calculate the shortest flight distance for the UAV to pass through all waypoints in sequence from the current position. The final reconnaissance route is generated by arranging the waypoints with the shortest flight distances. In this case, when the number of waypoints is large, the relatively optimal solution for the flight distance can be obtained quickly without consuming computing power.

[0073] Step 5: When the UAV is flying along the automatically generated reconnaissance route, the electro-optical linkage can be automatically activated based on the positional relationship between the UAV and various waypoints or areas, thereby achieving automatic reconnaissance; the specific implementation method is as follows:

[0074] Step 5-1: When the UAV flies to a waypoint that follows a "serpentine" fixed-point flight path, the activation of photoelectric linkage can be determined by whether the UAV has entered the local rectangular area calculated in Step 2. The photoelectric equipment automatically adjusts to move the turntable sequentially towards the calculated area using geographic guidance within a wide field of view, achieving area surveying. When it is determined that the UAV has entered a local rectangular area, the target point set requiring geographic guidance within that area is first calculated based on the coordinates of the four points within the local rectangular area. Subsequently, the UAV flies along the fixed-point flight path into the local rectangular area, and the photoelectric platform activates geographic guidance linkage. The geographic guidance method aligns the longer side of the field of view with the direction of the UAV's ground speed. The coordinates of the guided points are the set of geographic guidance target points calculated above, so that the photoelectric system points to the optical television field area where the geographic guidance target point is located to achieve regional reconnaissance. When the UAV flies away from the straight section of the "serpentine" flight path and enters the turning section, that is, when it leaves the local rectangular area, the photoelectric linkage stops. When the UAV enters the next local rectangular area again, the above process is repeated until the entire rectangular area is reconnoitered. During the reconnaissance process, the time interval of the geographic guidance target point is adjusted according to the real-time ground speed of the UAV to achieve synchronization between the UAV's movement and the photoelectric system's lateral back-and-forth geographic guidance. That is, when the UAV travels twice the long side field of view distance of the photoelectric system, the photoelectric system completes one cycle of lateral back-and-forth geographic guidance.

[0075] The above-mentioned method for calculating the target point set in a local rectangular area using photoelectric linkage and geographic guidance is shown in the following steps. In the calculation, since the field of view width directly below the photoelectric sensor is smaller than the field of view width diagonally downwards when the field of view angle is the same, the field of view of the photoelectric sensor when it reconnoiters laterally can be approximated as the field of view directly below. This ensures that there is overlap and no omission between the actual reconnaissance fields of view.

[0076] The first step is to calculate the long and short widths of the field of view of the optoelectronic device, using the following formula:

[0077]

[0078] Where S is the field of view width, km; P is the pixel size, μm; f is the optical lens focal length, mm; N is the number of pixels in the field of view direction, and the long side width S1 and short side width S2 of the field of view can be calculated separately according to the different number of pixels in the field of view direction; H is the UAV flight field height, km.

[0079] The second step involves determining the long side width S1 and short side width S2 of the optoelectronic device's field of view, as well as the angle ag, width d, and coordinates of its four vertices P1, P2, P3, and P4 of the local rectangular region. Figure 4 As shown, calculate the coordinates fp1, fp2, ..., fp* of the first column of the field of view center that requires photoelectric geographic guidance in the vertical direction of the UAV flight path.

[0080] The third step is to calculate the coordinates of the center point of the field of view requiring photoelectric geo-guidance along the UAV's flight path. The coordinates of the first group of points (fp1, fp2, ..., fp*) for lateral geo-guidance have already been obtained in the second step above. Figure 4 The distance between points fp1 and fp*`...fp* and fp1` is consistent with the distance S1 of the long side width of the optical television field. Therefore, the coordinates of the second group of points fp1`, fp2`...fp*` for horizontal geographic guidance can be obtained from the coordinates of points fp1, fp2...fp*. The coordinates of the remaining groups of geographic guidance points in the direction of the UAV flight path can be obtained by analogy. The number of groups n` is obtained by rounding up the result of dividing the length l of the local rectangular area by the long side width S1 of the optical television field.

[0081] Step 5-2: When the waypoint the drone flies to is a detailed reconnaissance waypoint, it can be determined whether the drone has entered the designated waypoint.

[0082] With the waypoint as the center and the distance of the UAV's minimum hovering diameter as the radius, the electro-optical linkage is activated. The electro-optical equipment automatically adjusts to move the turntable in a small field of view through geographic guidance, pointing it sequentially to the target points to be reconnoitered, thus achieving detailed observation of multiple target point sets. When the linkage is activated, the electro-optical equipment is automatically guided to the target point coordinates, i.e., the coordinates of the nearby points carried by this waypoint, until all nearby points and targets at the location of this waypoint are reconnoitered. Then, the electro-optical linkage is stopped and the system automatically switches to the next waypoint. After the conditions for activating the electro-optical linkage are met, the above process is repeated until all reconnaissance tasks are completed.

[0083] The following will describe in more detail each step of the electro-optical automatic linkage reconnaissance method applicable to fixed-wing UAVs in this exemplary embodiment, with reference to the accompanying drawings and embodiments.

[0084] Step 1: After the UAV system receives the reconnaissance area and multi-target point set mission package from the outside, because the reconnaissance area may be irregularly shaped, for example... Figure 1 The area formed by S1, S2, S3, S4, and S5 is shown. Therefore, the area to be reconnoitered is first automatically converted into a rectangular area that minimizes the size of this irregular area, facilitating automatic planning of reconnaissance routes and division of reconnaissance zones. The conversion method is as follows: Figure 1As shown, in the initial xoy coordinate system, point S1 has the largest latitude, point S4 has the smallest latitude, point S3 has the largest longitude, and point S5 has the smallest longitude. The maximum and minimum longitudes and latitudes are combined in pairs: the longitude of point R1 equals the longitude of point S5, and its latitude equals the latitude of point S1; the longitude of point R2 equals the longitude of point S3, and its latitude equals the latitude of point S1; the longitude of point R3 equals the longitude of point S3, and its latitude equals the latitude of point S4; the longitude of point R4 equals the longitude of point S5, and its latitude equals the latitude of point S4. This allows us to obtain a rectangular region composed of points R1, R2, R3, and R4 and calculate its area. The coordinate system is then rotated using the coordinate rotation method. Taking the maximum and minimum longitude and latitude of the irregular area to be investigated from 0 to 360 degrees, respectively, in the rotated SOT coordinate system, point S1 has the maximum latitude, point S3 has the minimum latitude, point S3 has the maximum longitude, and point S5 has the minimum longitude. Combining the maximum and minimum longitude and latitude in pairs yields the rectangular area formed by points R1', R2', R3', and R4', and the area is calculated. The calculation is completed after rotating the coordinate system by different degrees. The area of ​​the rectangle under the angle is compared, and the coordinates of the four points of the rectangle with the smallest area are obtained. These coordinates are then converted to point coordinates in the xoy coordinate system, resulting in the following: Figure 2 The rectangular area to be investigated is shown as having a length of l and a width of w.

[0085] Step 2: As Figure 2 As shown, based on the rectangular area information obtained in step 1, a "snake-like" fixed-point flight path that can completely cover the entire area for photoelectric reconnaissance is automatically generated. The angle of the "snake-like" fixed-point flight path is the same as the angle of the rectangular area, both being ag. The center point position is the same as the center point position of the rectangular area. The length is the length of the rectangular area l plus the interval d of the "snake-like" fixed-point flight path. The number of long side segments is the result of dividing the width w of the rectangular area by the interval d of the "snake-like" fixed-point flight path and rounding it up. The turning radius r of the "snake-like" fixed-point flight path is half of its interval d. The interval d depends on the recognition capability of the photoelectric platform carried by the UAV under the maximum field of view. Figure 3 As shown, when the UAV flies along the long side of the "serpentine" fixed-point flight path, the photoelectric platform can identify local targets within half the distance of the "serpentine" fixed-point flight path in the left and right vertical directions of the UAV's flight path. That is, the width of the local area is equal to the serpentine interval with a distance d. This local area is... Figure 3 The shaded areas shown in part1, part2, and part3 ensure that the UAV flies back and forth along the adjacent long sides of the "serpentine" fixed-point flight path without missing any areas. Together, they cover the rectangular area to be reconnoitered. At the same time, the coordinates of the four points of each of the local rectangular areas part1, part2, and part3 reconnoitered by the UAV along each long side of the "serpentine" flight path can be calculated. The length of the local rectangular area is the length of the rectangular area to be reconnoitered, and the width is the interval d of the "serpentine" fixed-point flight path.

[0086] The intervals of a "serpentine" fixed-point flight path can be calculated using the following steps:

[0087] Step 2-1: Calculate the recognition distance of the photoelectric device, using the following formula:

[0088]

[0089] Where L is the recognition distance of the photoelectric device, in km; h is the size of the target to be identified, set as a medium-sized vehicle, h = 10m; n is the number of line pairs, determined according to the minimum number of line pairs that the photoelectric device can identify, n = 4; P is the pixel size, P = 4.5um; f is the focal length of the optical lens in the wide field of view, f = 15mm.

[0090] Step 2-2: Calculate the field of view of the photoelectric device, using the following formula:

[0091]

[0092] Where α is the field of view angle, which is determined by the number of pixels on the long and short sides of the field of view in radians; P is the pixel size, P = 4.5 μm; f is the focal length of the optical lens, f = 15 mm; N is the number of pixels in the field of view direction, with the number of pixels on the long side set to 1920 and the number of pixels on the short side set to 1080.

[0093] Steps 2-3: Calculate the width of the local rectangle that the optoelectronic device can identify in the vertical direction of the UAV's long-side flight path, i.e., the "snake" interval d, as shown in the following formula:

[0094]

[0095] Where d is the width of the local rectangle that the optoelectronic device can identify in the vertical direction of the UAV's long side flight path, in km; H is the UAV's flight field height, with a typical reconnaissance field height of H = 3 km; L is the optoelectronic device's identification distance, calculated in step 2-1, in km; α is the optoelectronic short side field of view angle, calculated in step 2-2, in radians; to ensure that the UAV can identify ground targets, the UAV's reconnaissance field height H must be less than the identification distance L.

[0096] Based on the above calculations, the width of the local area and the serpentine intervals are equidistant, d≈7.73km.

[0097] Step 3: As Figure 6 As shown, target points 1 to 9 in the task package are categorized. The goal of this categorization is to ensure that when the UAV flies along the automatically generated reconnaissance route, it can detect all target points in the set while reducing the number of waypoints for the UAV, ultimately reducing the total flight distance and improving reconnaissance efficiency. The categorization method is as follows:

[0098] Step 3-1: Calculate the distance between each pair of target points in the set to be reconnoitered, and determine whether they are close to each other. If the distance is less than the proximity distance, they are considered close to each other; otherwise, they are not close to each other. The proximity distance is equal to the diameter of the minimum fixed-point hovering of the UAV.

[0099] Step 3-2: As Figure 6 As shown, based on the minimum hovering diameter of a certain fixed-wing UAV of 1km, the dashed 1km radius circle in the figure is used as a partial target point including the range of nearby points. The nearby points of each target point to be reconnoitered are obtained. The nearby point of point 1 is point 2, the nearby points of point 2 are points 1, 3, and 4, the nearby points of point 3 are points 2 and 4, the nearby points of point 4 are points 2 and 3, the nearby point of point 5 is point 6, the nearby points of point 6 are points 5 and 8, the nearby points of point 7 are points 8 and 9, the nearby points of point 8 are points 6 and 7, and the nearby point of point 9 is point 7. Starting from the target point to be reconnoitered with the most nearby points, the points are merged. That is, the target point to be reconnoitered with the most nearby points, point 2, is taken as the waypoint of the reconnaissance route. The number of nearby points it has is recorded as 3, and points 1, 3, and 4 are marked as its nearby points respectively.

[0100] Step 3-3: Start merging the remaining target points that have the second most or the same number of neighboring points as the target point with the most neighboring points. Before merging, first determine whether the target point has already been marked as a waypoint or a neighboring point of the reconnaissance route. If so, skip the point; otherwise, mark the point as a waypoint of the reconnaissance route, record the number of neighboring points it has, and mark these neighboring points respectively. Although points 3 and 4 have the second most neighboring points, this step allows us to skip points 3 and 4 that are marked as neighboring points first.

[0101] Step 3-4: Repeat step 3-3 above. Point 6 can be classified as a waypoint of the reconnaissance route, and its neighboring points 5 and 8 are marked. Continue repeating step 3-3. Point 7 can be classified as a waypoint of the reconnaissance route, and its neighboring points 8 and 9 are marked. Continue repeating step 3-3, skipping points 8, 1, 5, and 9 in sequence to complete the marking of all target points to be reconnaissance. At this point, you can obtain the attribute list of the target points to be reconnaissance, including whether it is a waypoint or a neighboring point of the reconnaissance route, and the number and sequence number of the neighboring points it has when it is a waypoint. However, after this step, there is a case where points 6 and 7 have the same neighboring point 8.

[0102] Steps 3-5: Remove duplicate neighboring points belonging to the reconnaissance route waypoints. The removal method is to skip the recorded neighboring points and processed points, and start from the reconnaissance route waypoint with the most neighboring points or the other target points with the same number of neighboring points. Record the serial numbers of its unrecorded neighboring points, delete the recorded neighboring points, and mark this reconnaissance route waypoint as a processed point; that is, start marking from the reconnaissance route waypoint 2 with the most neighboring points, and record its neighboring points 1, 3, and 4.

[0103] Steps 3-6: Repeat steps 3-5. First, skip the already recorded points 3 and 4. After repeating steps 3-5 again, mark point 6 as a reconnaissance route waypoint and record its neighboring points 5 and 8. Repeat again to mark point 7 as a reconnaissance route waypoint and record its neighboring point 9. Remove the neighboring point 8 that has already been recorded at point 6, until all reconnaissance route waypoints have been processed, and obtain the final list of attributes of the target points to be reconnaissance. Its attribute list includes: whether it is a waypoint or a nearby point on a reconnaissance route, the number and sequence of nearby points when it is a waypoint, and the type parameter of the waypoint; as shown above, point 2 is a waypoint on a reconnaissance route, with 3 nearby points, including points 1, 3, and 4; point 6 is a waypoint on a reconnaissance route, with 2 nearby points, including points 5 and 8; point 7 is a waypoint on a reconnaissance route, with 1 nearby point, including point 9; to improve the efficiency and stability of reconnaissance, there are two types of waypoints here, namely, through points or fixed-point routes with the minimum diameter of the UAV's disk; the type of waypoint is mainly determined by the number of nearby points it has, the cruising speed, the minimum diameter of the UAV's disk route, and the detailed parameters. The reconnaissance time for each target point is determined by the following strategy: Based on a cruising speed of 150 km / h and a minimum disk path diameter of 1 km, the time t1 ≈ 150 s for the UAV to circle once is calculated. The total reconnaissance time t2 for each waypoint is calculated based on the planned reconnaissance time of 30 s and the number of adjacent points. If t2 / t1 ≤ 0.5, the waypoint type is set as a passing point; if t2 / t1 > 0.5, the waypoint type is set as a disk, and the number of circles is t2 / t1 rounded up. It can be calculated that point 2 is a disk waypoint with 1 circle, and points 6 and 7 are passing points.

[0104] Step 4: Arrange the coordinates of all waypoints in the target point attribute list obtained in Step 3 and the coordinates of the "serpentine" fixed-point route obtained in Step 2 to automatically generate the final reconnaissance route. The goal of the reconnaissance route is to minimize the distance traveled by the UAV from its current position through the above waypoints. The method for automatically generating the reconnaissance route is as follows:

[0105] Case 1: When the number of waypoints for the reconnaissance route is less than 10, the "exhaustive method" is used to perform a full permutation of the waypoints for the reconnaissance route. The flight distance of the UAV from the current position through each permutation of waypoints is calculated. The final reconnaissance route is generated by the waypoint permutation with the shortest flight distance. In this case, the optimal flight distance can be achieved when the number of waypoints is small, without consuming computer computing power.

[0106] Scenario 2: When the number of waypoints on the reconnaissance route is greater than or equal to 10, the "exhaustive search method" consumes a lot of computing power. To improve computing efficiency, the "Dijkstra algorithm" is selected to calculate the shortest flight distance for the UAV to pass through all waypoints in sequence from the current position. The final reconnaissance route is generated by arranging the waypoints with the shortest flight distances. In this case, when the number of waypoints is large, the relatively optimal solution for the flight distance can be obtained quickly without consuming computing power.

[0107] Step 4 above can generate the following: Figure 7 The reconnaissance route starts at the UAV's current coordinates as point C1. Point C2 is a circular fixed-point route with a diameter of 1km, and its coordinates are consistent with point 2 to be reconnoitered. Point C3 is a passing point, and its coordinates are consistent with point 6 to be reconnoitered. Point C4 is a passing point, and its coordinates are consistent with point 7 to be reconnoitered. Point C5 is a "snake-shaped" fixed-point route, and its center point coordinates are consistent with the center point of the rectangular area to be reconnoitered. Among them, C1, C2, C3, and C4 are waypoints for detailed reconnaissance of the target points to be reconnoitered, while C5 is a waypoint for general reconnaissance of the area to be reconnoitered.

[0108] Step 5: When the UAV is flying along the automatically generated reconnaissance route, the electro-optical linkage can be automatically activated based on the positional relationship between the UAV and various waypoints or areas, thereby achieving automatic reconnaissance; the specific implementation method is as follows:

[0109] Step 5-1: As Figure 4 and Figure 5As shown, when the UAV flies to a waypoint along a "serpentine" fixed-point route, the decision to activate photoelectric linkage can be made by determining whether the UAV enters the locally rectangular area (part) calculated in step 2. The photoelectric equipment automatically adjusts to move the turntable sequentially towards the calculated area using geographic guidance within a wide field of view, achieving area surveying. When it is determined that the UAV has entered the locally rectangular area (part1), the set of center points of the field of view requiring geographic guidance within part1 is first calculated based on the coordinates of the four points of part1. Subsequently, the UAV flies along the fixed-point route into the locally rectangular area (part), and the photoelectric platform activates geographic guidance linkage. The geographic guidance method aligns the long side of the field of view with the direction of the UAV's ground speed. The center coordinates of the guided field of view are sequentially fp1, fp2, ..., fp*, fp1`, fp2`, ..., fp*`, etc., so that the photoelectric sensor points sequentially to the optical field of view areas where fp1, fp2, ... are located to achieve area reconnaissance. When the UAV leaves the straight section of the "serpentine" flight path and enters the turning section, that is, when it leaves the local rectangular area part1, the photoelectric linkage stops. When the UAV enters the next local rectangular area part2, the above process is repeated until the entire rectangular area is reconnoitered. During the reconnaissance process, the time interval of each field of view of the geographic guidance is adjusted according to the real-time ground speed of the UAV to achieve synchronization between the UAV's movement and the photoelectric sensor's lateral back-and-forth geographic guidance. That is, when the UAV has traveled twice the distance of the long side of the photoelectric sensor's field of view, for example, when the UAV starts from... Figure 3 When point a travels to point b, the distance between point a and point b is twice the distance of the long side of the optical television field. At the same time, the photoelectric device completes one cycle of horizontal back-and-forth geographical guidance, that is, the photoelectric device sequentially guides the field of view of each center point fp1, fp2...fp*, fp1`, fp2`...fp*`.

[0110] The above-mentioned method for calculating the target point set in the local rectangular area part1 under photoelectric linkage geographic guidance is shown in the following steps. In the calculation, since the field of view width directly below the photoelectric sensor is smaller than the field of view width diagonally downward when the field of view angle is the same, the field of view of the photoelectric sensor when it is reconnoitering laterally can be approximated as the field of view directly below. This can ensure that there is overlap and no omission between the actual reconnaissance fields of view.

[0111] The first step is to calculate the long and short widths of the field of view of the optoelectronic device, using the following formula:

[0112]

[0113] Where S is the field of view width, km; P is the pixel size, P = 4.5 μm; f is the optical lens focal length, f = 15 mm; N is the number of pixels in the field of view direction. The long side width S1 and the short side width S2 of the field of view can be calculated separately according to the different number of pixels in the field of view direction. The number of pixels on the long side is set to 1920, and the number of pixels on the short side is set to 1080; H is the UAV flight field height, H = 3 km.

[0114] Calculations show that the width of the longer side is S1≈1.68km and the width of the shorter side is S2≈0.96km.

[0115] The second step involves calculating the coordinates of the center point of the first column of the field of view requiring photoelectric geographic guidance in the vertical direction of the UAV's flight path, based on the long side width S1 and short side width S2 of the optoelectronic equipment's field of view, the angle ag, width d of the local rectangular region part, and the coordinates of its four vertices P1, P2, P3, and P4. The calculation method is as follows: first calculate... Figure 5 The coordinates of the auxiliary calculation point fp` on the flight path are shown. fp` is the point located half the width of the longer side to the right of point a, the intersection of the line connecting P1 and P2 and its perpendicular bisector, i.e., a distance of S1 / 2. Next, rounding up the result of d / S2 gives the number of field-of-view centers requiring photoelectric geographic guidance in the vertical direction of the UAV flight path: n = 8, where n is an even number. The distance between fp1 and fp` is... If n is odd, the distance between point fp1 and point fp` is The coordinates of point fp1 can be obtained from the coordinates of point fp` and the distance and angle between the two points. The distance between two adjacent points fp1, fp2, ..., fp* is consistent with the distance of the short side width S2 of the optical television field. Since the angle of the local rectangular region part is known, the other points can be obtained from point fp1.

[0116] The third step is to calculate the coordinates of the center point of the field of view requiring photoelectric geo-guidance along the UAV's flight path. The coordinates of the first group of points (fp1, fp2, ..., fp*) for lateral geo-guidance have already been obtained in the second step above. Figure 5 The distance between points fp1 and fp*`...fp* and fp1` is consistent with the distance S1 of the long side width of the optical television field. Therefore, the coordinates of the second group of points fp1`, fp2`...fp*` for horizontal geographic guidance can be obtained from the coordinates of points fp1, fp2...fp*. The coordinates of the remaining groups of geographic guidance points in the direction of the UAV flight path can be obtained by analogy. The number of groups n` is obtained by rounding up the result of dividing the length l of the local rectangular area part by the long side width S1 of the optical television field.

[0117] Step 5-2: As Figure 7As shown, when the waypoint the UAV flies to is a detailed reconnaissance waypoint, the electro-optical linkage can be activated by determining whether the UAV has entered an area with the waypoint as the center and the distance of the UAV's minimum fixed-point hovering diameter as the radius. The electro-optical equipment will automatically adjust to move the turntable in a small field of view through geographic guidance, pointing to the target points to be reconnoitered in sequence, thus achieving detailed reconnaissance of multiple target points. After the linkage is activated, the electro-optical equipment will automatically guide the UAV to the target point coordinates, i.e., the coordinates of the nearby points carried by this waypoint. For example, after entering an area within 1km of point C2, the UAV will enter the circular route of point C2, and at the same time, the electro-optical equipment will activate the geographic guidance linkage, pointing to points 1, 3, 4, and 2 to be reconnoitered in sequence. That is, the reconnaissance of all nearby points and the target at the location of this waypoint will be completed. Then the electro-optical linkage will stop and automatically switch to the next waypoint C3. After the conditions for activating the electro-optical linkage are met, the above process will be repeated until all reconnaissance tasks are completed.

[0118] This invention enables a fixed-wing UAV to automatically generate a reconnaissance route that is coupled with the identification capabilities of an optoelectronic platform and closely linked to the area to be reconnoitered and a set of multiple target points. During the flight of this route, the optoelectronic platform automatically coordinates with the position of the UAV on the route to conduct a general survey of the area to be reconnoitered and a detailed survey of the set of multiple target points. This effectively improves the identification probability and reconnaissance efficiency, greatly reduces the burden on personnel, and enhances the flexibility of UAV tactical applications.

[0119] It should be noted that, as another aspect, this application also provides a storage medium, which may be included in an electronic device or may exist independently without being assembled into the electronic device. The aforementioned storage medium carries one or more programs, which, when executed by an electronic device, cause the electronic device to perform the methods described in the following embodiments. For example, the electronic device may perform... Figure 2 The steps of the method shown.

[0120] In one embodiment, this application provides a computer program product including a computer program that, when executed by a processor, implements the steps in the above-described method embodiments.

[0121] Furthermore, the above figures are merely illustrative of the processes included in the method according to exemplary embodiments of the present invention, and are not intended to be limiting. It is readily understood that the processes shown in the above figures do not indicate or limit the temporal order of these processes. Additionally, it is readily understood that these processes may be executed synchronously or asynchronously, for example, in multiple modules.

[0122] Other embodiments of the invention will readily occur to those skilled in the art upon consideration of the specification and practice of the invention herein. This application is intended to cover any variations, uses, or adaptations of the invention that follow the general principles of the invention and include common knowledge or customary techniques in the art not disclosed herein. The specification and embodiments are to be considered exemplary only, and the true scope and spirit of the invention are indicated by the claims.

[0123] It should be understood that the present invention is not limited to the precise structure described above and shown in the accompanying drawings, and various modifications and changes can be made without departing from its scope. The scope of the invention is limited only by the appended claims.

Claims

1. A photoelectric automatic linkage reconnaissance method suitable for fixed-wing unmanned aerial vehicles, characterized in that, The method includes: Receive a mission package from the superior command system containing the area to be reconnoitered and a set of multiple targets to be reconnoitered; Based on the area to be reconnoitered, a serpentine fixed-point route and the local rectangular area reconnoitered by the UAV on each long side of the serpentine fixed-point route are determined. The set of multi-target points to be reconnoitered is categorized to obtain a set of detailed waypoints containing attribute lists; Arrange the serpentine fixed-point route and the detailed reconnaissance waypoint set to generate a reconnaissance route with the shortest travel distance for the UAV to pass through the arranged waypoints sequentially from the current position. The drone is controlled to fly autonomously along the reconnaissance route. Based on the positional relationship between the drone and the local rectangular area or each detailed reconnaissance waypoint, photoelectric linkage is automatically activated to achieve automatic reconnaissance. The method further includes: The area to be detected is automatically converted into a minimum rectangular area that covers this irregular area; including: The maximum and minimum longitude and latitude of the irregular area to be investigated are calculated by using the coordinate rotation method, with the coordinate system rotated from 0 to 360 degrees respectively. The maximum and minimum longitude and latitude are combined in pairs to obtain a rectangular area. The area of ​​the rectangle under different rotation angles is calculated respectively. The coordinates of the points of the rectangle with the smallest area are converted into the point coordinates in the xoy coordinate system to obtain the rectangular area to be investigated. Based on the rectangular area to be investigated, a serpentine fixed-point route is determined.

2. The photoelectric automatic linkage reconnaissance method for fixed-wing UAVs according to claim 1, characterized in that, The step of determining the serpentine fixed-point route based on the rectangular area to be detected includes: The angle of the serpentine fixed-point route is the angle of the rectangular area to be reconnoitered; the center point position is the center point position of the rectangular area to be reconnoitered; the length is the length of the rectangular area to be reconnoitered plus the interval of the serpentine fixed-point route; the number of long side segments is the result of dividing the width of the rectangular area to be reconnoitered by the interval of the serpentine fixed-point route and rounding it up; the turning radius is half of the interval of the serpentine fixed-point route.

3. The photoelectric automatic linkage reconnaissance method for fixed-wing UAVs according to claim 2, characterized in that, The method for calculating the interval of the serpentine fixed-point route includes: Calculate the recognition distance of the photoelectric device; Calculate the field of view of the optoelectronic device; Based on the recognition distance of the optoelectronic device, the field of view of the optoelectronic device, and the height of the UAV flight field, the width of the local rectangle that the optoelectronic device can recognize in the vertical direction of the UAV's long side flight path is calculated, i.e., the interval of the serpentine fixed-point flight path.

4. The photoelectric automatic linkage reconnaissance method for fixed-wing UAVs according to claim 1, characterized in that, The set of multiple targets to be reconnoitered is categorized to obtain a detailed waypoint set, including: Calculate the distance between each pair of the target points in the set to be detected, and determine whether they are close to each other. If the distance is less than the proximity distance, they are considered close to each other; otherwise, they are not close to each other. The proximity distance is equal to the diameter of the minimum fixed-point hovering of the UAV. Obtain the neighboring points of each target point to be scouted, and start merging from the target point with the most neighboring points. That is, take the target point with the most neighboring points as the waypoint of the scouted route, record the number of neighboring points it has, and mark these neighboring points respectively. Merge the remaining target points that have the second most or the same number of adjacent target points as the target point with the most adjacent points. Before merging, first determine whether the target point has been marked as a waypoint or adjacent point of the reconnaissance route. If so, skip the point. Otherwise, mark the point as a waypoint of the reconnaissance route, record the number of adjacent points it has, and mark these adjacent points respectively. After removing duplicate neighboring points of the reconnaissance route waypoint, a list of attributes of the target point to be reconnoitered is obtained, including whether it is a waypoint or a neighboring point of the reconnaissance route, the number and sequence of neighboring points when it is a waypoint, and the type parameter of the waypoint.

5. The photoelectric automatic linkage reconnaissance method for fixed-wing UAVs according to claim 1, characterized in that, Arranging the serpentine fixed-point route and the detailed waypoint set includes: When the number of waypoints included in the serpentine fixed-point route and the number of waypoints in the detailed reconnaissance set are less than the threshold, the exhaustive method is used to perform a full permutation of the waypoints of the reconnaissance route, calculate the flight distance of the UAV from the current position through each permutation of waypoints, and generate the final reconnaissance route by the waypoint permutation of the shortest flight distance obtained. When the number of waypoints included in the serpentine fixed-point route and the number of waypoints in the detailed reconnaissance set are greater than or equal to the threshold, the Dijkstra algorithm is used to calculate the shortest flight distance for the UAV to pass through all waypoints sequentially from the current position, and the final reconnaissance route is generated by arranging the waypoints with the obtained shortest flight distances.

6. The photoelectric automatic linkage reconnaissance method for fixed-wing UAVs according to claim 1, characterized in that, The automatic activation of photoelectric linkage based on the positional relationship between the UAV and a local rectangular area or various detailed waypoints includes: When the UAV flies along a serpentine fixed-point flight path, the system determines whether it has entered a local rectangular area to activate the electro-optical linkage. The electro-optical equipment automatically adjusts to move the turntable under a wide field of view using geographic guidance, sequentially pointing towards the calculated area to achieve area surveying. When entry into a local rectangular area is detected, the system first calculates the target point set requiring geographic guidance within that area based on the coordinates of four points within the local rectangular area. Then, as the UAV flies along the fixed-point flight path and enters the local rectangular area, the electro-optical platform activates geographic guidance. The geographic guidance method aligns the longer side of the field of view with the direction of the UAV's ground speed, guiding the coordinate points sequentially as follows: The calculated set of geographic guidance target points enables the photoelectric system to sequentially point to the optical television field area where the geographic guidance target point is located to achieve regional reconnaissance. When the UAV leaves the straight section of the serpentine flight path and enters the turning section, that is, when it leaves the local rectangular area, the photoelectric linkage stops. When the UAV enters the next local rectangular area again, the above process is repeated until the entire rectangular area is reconnoitered. During the reconnaissance process, the time interval of the geographic guidance target point is adjusted according to the real-time ground speed of the UAV to achieve synchronization between the UAV's movement and the photoelectric system's lateral back-and-forth geographic guidance. That is, when the UAV travels twice the long side field of view distance of the photoelectric system, the photoelectric system simultaneously completes one cycle of lateral back-and-forth geographic guidance. When the waypoint the UAV flies to is a detailed reconnaissance waypoint, the electro-optical linkage is activated by determining whether the UAV has entered an area with the waypoint as the center and the distance of the UAV's minimum fixed-point hovering diameter as the radius. The electro-optical equipment is automatically adjusted to move the turntable in a small field of view through geographic guidance, pointing to the target points to be reconnoitered in sequence to achieve detailed reconnaissance of multiple target points. After the linkage is activated, the electro-optical equipment is automatically guided to the target point coordinates, i.e., the coordinates of the nearby points carried by this waypoint, until all nearby points and targets at the location of this waypoint are reconnoitered. Then the electro-optical linkage is stopped and the UAV automatically switches to the next waypoint. After the conditions for activating the electro-optical linkage are met, the above process is repeated until all reconnaissance tasks are completed.

7. A storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by the processor, it implements the electro-optical automatic linkage reconnaissance method applicable to fixed-wing UAVs as described in any one of claims 1 to 6.

8. A computer program product, comprising a computer program, characterized in that, When the computer program is executed by the processor, it implements the electro-optical automatic linkage reconnaissance method applicable to fixed-wing UAVs as described in any one of claims 1 to 6.

Images