Unmanned aerial vehicle landing method, unmanned aerial vehicle, storage medium and program product

Abstract

The invention relates to the technical field of unmanned aerial vehicles, and discloses an unmanned aerial vehicle landing method, an unmanned aerial vehicle, a storage medium and a program product, and the method comprises the steps: when the unmanned aerial vehicle flies to the air above a target landing position, the unmanned aerial vehicle is controlled to descend, and the target landing position is provided with a first identification code and an identification code combination comprising a plurality of second identification codes; the size of the second identification code is smaller than that of the first identification code; when the height of the unmanned aerial vehicle is larger than a first height threshold value, the unmanned aerial vehicle is controlled to scan the first identification code, the unmanned aerial vehicle is controlled to continue to descend after position adjustment based on the position relation between the scanned first identification code and the unmanned aerial vehicle, and the first height threshold value is related to the size of the second identification code; when the height of the unmanned aerial vehicle is smaller than or equal to the first height threshold value, the unmanned aerial vehicle is controlled to scan the identification code combination, and the unmanned aerial vehicle is controlled to continue to descend to the target landing position after position adjustment based on the position relation between the scanned second identification code and the unmanned aerial vehicle. The problem of low landing accuracy of the unmanned aerial vehicle can be solved.

Description

Technical Field

[0001] This invention relates to the field of unmanned aerial vehicle (UAV) technology, specifically to UAV landing methods, UAVs, storage media, and software products. Background Technology

[0002] Drone landing technology primarily relies on a fusion of Global Navigation Satellite System (GNSS) point positioning and traditional visual markers for navigation. However, GNSS point positioning is affected by satellite signals, weather, and other factors, resulting in poor positioning accuracy and making it difficult for drones to land stably at designated locations, leading to low drone landing precision. Summary of the Invention

[0003] This invention provides a drone landing method, a drone, a storage medium, and a program product to solve the problem of low drone landing accuracy.

[0004] In a first aspect, the present invention provides a method for landing a drone, the method comprising: When the drone flies over the target landing location, it is controlled to descend; wherein the target landing location is provided with a first identifier and a combination of identifiers; the combination of identifiers includes multiple second identifiers; the size of the second identifier is smaller than the size of the first identifier; When the drone's altitude is greater than a first altitude threshold, the drone is controlled to scan the first identification code. Based on the relationship between the scanned first identification code and the drone's position, the drone is controlled to adjust its position and continue to descend. The first altitude threshold is related to the size of the second identification code. When the drone's altitude is less than or equal to the first altitude threshold, the drone is controlled to scan the identification code combination. Based on the relationship between the scanned second identification code and the drone's position, the drone is controlled to adjust its position and descend to the target landing position.

[0005] In a second aspect, the present invention provides a drone, comprising: The main body of the drone; A flight control motherboard is used to execute the drone landing method described in the first aspect or any of its corresponding embodiments.

[0006] Thirdly, the present invention provides a computer-readable storage medium storing computer instructions for causing a computer to execute the unmanned aerial vehicle landing method of the first aspect or any corresponding embodiment thereof.

[0007] Fourthly, the present invention provides a computer program product, including computer instructions for causing a computer to execute the unmanned aerial vehicle landing method of the first aspect or any corresponding embodiment described above.

[0008] The drone landing method provided in this application embodiment has a first identifier and a combination of identifiers at the target landing location. The identifier combination includes multiple second identifiers, each smaller than the first identifier. Therefore, during drone landing, when the drone's altitude is above a first altitude threshold, coarse positioning of the drone at a long distance can be achieved by scanning the first identifier. The drone's position is then adjusted using the relationship between the scanned first identifier and the drone's position, thereby improving the accuracy of the drone landing. Conversely, when the drone's altitude is less than or equal to the first altitude threshold, fine positioning of the drone at close range can be achieved by scanning the identifier combination. The drone's position is further adjusted using the relationship between the scanned second identifiers and the drone's position, thus effectively improving the accuracy of the drone landing through multiple position adjustments.

[0009] The beneficial effects of drones, storage media, and computer program products correspond to the beneficial effects of drone landing methods, and will not be elaborated upon here. Attached Figure Description

[0010] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0011] Figure 1 This is a schematic diagram of a target according to an embodiment of the present invention; Figure 2 This is a schematic diagram of the first type of drone landing method according to an embodiment of the present invention; Figure 3 This is a schematic diagram of a second process for a drone landing method according to an embodiment of the present invention; Figure 4 This is a structural block diagram of a drone landing device according to an embodiment of the present invention. Detailed Implementation

[0012] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0013] It is understood that before using the technical solutions disclosed in the various embodiments of the present invention, users should be informed of the types, scope of use, and usage scenarios of the personal information involved in the present invention and their authorization should be obtained in accordance with relevant laws and regulations through appropriate means.

[0014] The terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0015] Drone landing technology primarily relies on a fusion of GNSS point positioning and traditional visual markers for navigation. However, this method of drone landing has the following problems: 1. GNSS single-point positioning is affected by satellite signals, weather, etc., resulting in poor positioning accuracy, which makes it difficult for drones to land stably at the designated location and results in low drone landing accuracy.

[0016] 2. The Aruco code used for visual marking has a significantly reduced recognition rate when it is obstructed (such as fallen leaves or water accumulation), changes in lighting (such as strong reflection or weak light), or changes in altitude (such as a narrowing of the field of view), which can easily lead to drone landing failure.

[0017] 3. Most drone landing systems use single-stage guidance, resulting in unstable landing trajectories and low fault tolerance.

[0018] Based on this, attempts were made to use a double-layer Aruco code layout with a larger outer layer and a smaller inner layer to improve recognition capabilities at different altitudes, but this still could not solve the problem of partial occlusion of the Aruco code. Furthermore, attempts were made to improve the positioning accuracy of Real-Time Kinematic (RTK) technology to the centimeter level, but its use alone still falls short of meeting the precise alignment requirements of drones during landing.

[0019] According to an embodiment of the present invention, a method for landing a drone is provided. It should be noted that the steps shown in the flowchart in the accompanying drawings can be executed in a computer system such as a set of computer-executable instructions. Furthermore, although a logical order is shown in the flowchart, in some cases, the steps shown or described may be executed in a different order than that shown here.

[0020] This embodiment provides a method for landing a drone, which can be used in a drone, specifically in the flight control motherboard of the drone. The target landing location of the drone is marked with a target, such as... Figure 1 As shown, the target includes a first identifier and a combination of identifiers (also known as Aruco board codes). The number of first identifiers can be one or more, and the identifier combination includes multiple second identifiers, the size of which is smaller than the size of the first identifier. The first identifier is used for long-range visual recognition, and the second identifiers are used for short-range visual recognition. In practical applications, the sizes of the first and second identifiers can be determined according to the actual situation of the drone to ensure that the drone can clearly identify the first identifier at long distances and the second identifier at close ranges. Optionally, the first and second identifiers are Aruco codes. Furthermore, QR codes, barcodes, or other identifiers used for visual calibration can be selected according to actual needs; no limitation is made here.

[0021] Figure 2 This is a flowchart of a drone landing method according to an embodiment of the present invention, such as... Figure 2 As shown, the process includes the following steps: Step S201: When the drone flies over the target, control the drone to descend.

[0022] Specifically, RTK technology guides the drone to fly over the target. Specifically, RTK positioning guides the drone to fly directly above the target. The horizontal position error of the drone relative to the target's landing position / target does not exceed a preset horizontal error (e.g., 1m). Simultaneously, when the drone's altitude error relative to the preset starting scan altitude does not exceed a preset altitude error (e.g., 0.5m), the drone is controlled to descend.

[0023] Step S202: When the drone's altitude is greater than the first altitude threshold, control the drone to scan the first identification code. Based on the relationship between the scanned first identification code and the drone's position, control the drone to adjust its position and continue to descend. The first altitude threshold is related to the size of the second identification code.

[0024] Optionally, the first height threshold is 1m, which can be adjusted according to the actual situation, such as 90cm, 1.1m, etc.

[0025] Specifically, when the drone's altitude exceeds a first altitude threshold, the drone is controlled to scan a first identification code. Based on the relationship between the scanned first identification code and the drone's position, first offset information of the drone relative to the target landing position is obtained. Based on the first offset information, the drone is controlled to adjust its position, and after adjusting its position, the drone is controlled to continue descending.

[0026] In practical applications, the position information of the first identifier code, such as the position information of the center point of the first identifier code, is pre-configured. Based on the position information of the first identifier code and the position information of the target landing position, the positional relationship of the first identifier code relative to the target landing position is configured. Then, the current position information of the UAV is obtained. Based on the position information of the scanned first identifier code and the current position information of the UAV, the positional relationship between the scanned first identifier code and the UAV is obtained. Then, based on the positional relationship of the first identifier code relative to the target landing position, and the positional relationship between the scanned first identifier code and the UAV, the first offset information of the UAV relative to the target landing position is obtained.

[0027] It should be noted that in practical applications, the relationship between the scanned first identifier and the position of the UAV can be determined based on the camera parameters (including lens parameters) of the image acquisition device and the target image acquired by the image acquisition device, so as to obtain the first offset information of the UAV relative to the target landing position.

[0028] Optionally, the first offset information includes at least one of the first horizontal offset of the UAV relative to the target landing position and the first rotation angle offset, which can be adjusted according to the actual situation.

[0029] Furthermore, the aforementioned control of the UAV to adjust its position based on the first offset information includes: controlling the UAV to adjust its horizontal position based on a first horizontal offset of the UAV relative to the target landing position; and controlling the UAV to adjust its rotation angle based on a first rotation angle offset of the UAV relative to the target landing position.

[0030] In practical applications, the steps in S202 above can be repeated until the drone's altitude is less than or equal to a first altitude threshold. For example, the first identifier code can be scanned periodically. Alternatively, multiple preset altitude levels can be set in advance, and the drone can be controlled to scan the first identifier whenever it descends to a preset altitude. The preset altitude is greater than the first altitude threshold. Each time the first identifier code is scanned, the drone's position is adjusted based on the scanned identifier code and the drone's position, and the drone continues to descend.

[0031] It should be noted that the first identifier scanned above refers to the first identifier that can be normally recognized by the drone.

[0032] Step S203: When the drone's altitude is less than or equal to the first altitude threshold, control the drone to scan the identification code combination. Based on the relationship between the scanned second identification code and the drone's position, control the drone to adjust its position and control the drone to descend to the target landing position.

[0033] Specifically, when the drone descends to an altitude less than or equal to a first altitude threshold, the drone is controlled to scan a combination of identification codes. Based on the relationship between the scanned second identification code and the drone's position, second offset information of the drone relative to the target landing position is obtained. Based on the second offset information, the drone is controlled to adjust its position, and after adjusting its position, the drone is controlled to descend to the target landing position.

[0034] In practical applications, the position information of the second identifier code, such as the position of its center point, is pre-configured. Based on the position information of the second identifier code and the position information of the target landing position, the positional relationship of the second identifier code relative to the target landing position is configured. Then, the current position information of the UAV is obtained. Based on the position information of the scanned second identifier code and the current position information of the UAV, the positional relationship between the scanned second identifier code and the UAV is obtained. Finally, based on the positional relationship between the second identifier code and the target landing position, and the positional relationship between the scanned second identifier code and the UAV, the second offset information of the UAV relative to the target landing position is obtained.

[0035] It should be noted that in practical applications, the positional relationship between the scanned second identifier and the UAV can also be determined based on the camera parameters (including lens parameters) of the image acquisition device and the target image acquired by the image acquisition device, so as to obtain the second offset information of the UAV relative to the target landing position.

[0036] Optionally, the second offset information includes at least one of a second horizontal offset of the UAV relative to the target landing position and a second rotation angle offset, which can be adjusted according to the actual situation.

[0037] Furthermore, the aforementioned control of the UAV's position adjustment based on the second offset information includes: controlling the UAV to adjust its horizontal position based on the second horizontal offset of the UAV relative to the target landing position; and controlling the UAV to adjust its rotation angle based on the second rotation angle offset of the UAV relative to the target landing position.

[0038] It should be noted that after the drone is adjusted based on the second offset information, the horizontal position error of the drone relative to the target landing position should be less than the preset offset error (e.g., 10cm). Continue to control the drone to descend until the drone reaches the target landing position.

[0039] The drone landing method provided in this embodiment uses a first identifier and a combination of identifiers at the target landing location. The identifier combination includes multiple second identifiers, each smaller than the first identifier. Therefore, during drone landing, when the drone's altitude is above a first altitude threshold, coarse positioning of the drone at a long distance can be achieved by scanning the first identifier. The drone's position is then adjusted using the relationship between the scanned first identifier and the drone's position, thereby improving landing accuracy. Conversely, when the drone's altitude is less than or equal to the first altitude threshold, fine positioning of the drone at close range can be achieved by scanning the identifier combination. The drone's position is further adjusted using the relationship between the scanned second identifiers and the drone's position, thus effectively improving landing accuracy through multiple position adjustments.

[0040] In some alternative implementations, the second identifier is of a different type than the first identifier, and there are differences between the various second identifiers in the identifier combination.

[0041] That is, the second identifier in the identifier combination is of a different type from all the first identifiers, and the second identifier and the first identifier belong to different unique codes (IDs).

[0042] Optionally, the second identifiers in the identifier combination can be of the same type. Of course, the second identifiers in the identifier combination can also be partially of the same type and partially different. For example, the second identifiers in the same row can be of the same type, while the second identifiers in different rows can be of different types; this can be chosen according to the actual situation.

[0043] refer to Figure 1 Even if 25% of the 25 second identifiers shown are obscured, 75% of the second identifiers can still be recognized normally. Therefore, it can effectively improve the anti-obscuration capability of the identifiers.

[0044] The UAV landing method provided in this embodiment, because the second identifier code and the first identifier code are of different types, and there are differences between the various second identifier codes in the identifier code combination, can easily distinguish between the first identifier code used for long-range identification and the second identifier code used for short-range identification, and can easily distinguish between second identifier codes at different positions, thereby achieving accurate visual positioning at close range. Moreover, when any second identifier code is occluded, there are still other second identifier codes that can be used for visual positioning, improving the anti-occlusion effect of the second identifier code and increasing the recognition rate of the second identifier code.

[0045] In some alternative implementations, the number of first identifiers is at least two, and there are differences between the various first identifiers.

[0046] For example, the target includes a first identification code A and a first identification code B, which are used for visual identification when the UAV is far from the target landing position. The first identification codes A and B are different.

[0047] The drone landing method provided in this embodiment configures at least two first identifier codes on the target, and the first identifier codes are different from each other. Therefore, even if any first identifier code is obstructed, the drone's deviation can still be determined by the other first identifier codes on the target, improving the anti-obstruction effect of the first identifier codes at long distances.

[0048] In some alternative implementations, as the drone flies over the target landing location, controlling the drone to descend includes: Step a1: Obtain real-time situational information of the UAV.

[0049] Specifically, real-time situational information of the UAV is obtained through GPS positioning and / or RTK positioning.

[0050] RTK positioning consists of a base station, an airborne rover station, and a data transmission (e.g., 4G) data link. The base station calculates error correction values ​​based on its coordinates and carrier phase observations, then transmits these error correction values ​​to the airborne rover station in real time via the data link. The airborne rover station corrects the measured UAV positioning information based on the error correction values, obtaining real-time UAV situational awareness information, thereby eliminating errors in the positioning process and achieving higher horizontal positioning accuracy for the UAV.

[0051] Step a2: Based on real-time situational information, control the UAV to fly over the target landing location.

[0052] Specifically, the preset flight path of the drone is obtained; the preset flight path is used to guide the drone to the target landing position.

[0053] In practical applications, a preset flight path can be obtained by: acquiring the drone's takeoff position and target landing position; and then planning the drone's flight path based on the takeoff and landing positions to obtain the preset flight path.

[0054] Then, based on the drone's preset flight path and real-time situational information, the drone is controlled to fly towards the target landing location. That is, based on the preset flight path and the drone's real-time situational information, the drone is controlled to fly towards the target landing location until it reaches the target.

[0055] Step a3: When the horizontal position error of the UAV relative to the target landing position is less than the preset horizontal error and the height of the UAV is less than the starting scanning height, control the UAV to descend; wherein, the starting scanning height is greater than the first height threshold and the starting scanning height is related to the size of the first identification code.

[0056] Optionally, the preset horizontal error is 1m, which can be adjusted according to the actual situation, such as 0.9m.

[0057] Optionally, the starting scanning height can be in the range of 20~30m, such as 30m.

[0058] It should be noted that the initial scanning height should be set to ensure that the drone's image acquisition device can scan a clear first identification code. Therefore, in practical applications, the initial scanning height can be determined by combining the size of the first identification code and the lens parameters of the image acquisition device. When the drone's altitude is lower than the initial scanning height, the drone's visual scanning function should be activated. That is, the drone's image acquisition device should scan the first identification code and / or a combination of identification codes.

[0059] The drone landing method provided in this embodiment first controls the drone to fly above the target landing position using real-time situational information, thus ensuring flight efficiency. The drone is only controlled to descend when its horizontal position error relative to the target landing position is less than a preset horizontal error and its altitude is less than the initial scanning altitude. Simultaneously, the initial scanning altitude is related to the size of the first identification code, ensuring that the drone's image acquisition device can scan a clear first identification code during descent, improving identification code recognition efficiency. Furthermore, by visually recognizing the identification code, the drone's position is adjusted to improve descent accuracy.

[0060] In some optional implementations, step S202 above, which involves controlling the drone to scan the first identification code and adjusting the drone's position based on the scanned first identification code and the drone's position, includes: Step b1: If the drone's altitude is greater than the second altitude threshold, control the drone to scan the first identifier code. Based on the relationship between the scanned first identifier code and the drone's position, and the relationship between the scanned second identifier code and the drone's position, control the drone to adjust its position.

[0061] The second height threshold is greater than the first height threshold, and the second height threshold is related to the size of the first identifier and the size of the second identifier.

[0062] Optionally, the second height threshold is 10m, which can be adjusted according to the actual situation, such as 11m, 9m, etc.

[0063] Specifically, when the drone's altitude exceeds a second altitude threshold, the drone is controlled to scan a first identification code. Based on the relationship between the scanned first identification code and the drone's position, first offset information of the drone relative to the target landing position is obtained. Based on the first offset information, the drone is controlled to adjust its position, and after adjusting its position, the drone is controlled to continue descending.

[0064] It is worth noting that the second height threshold is less than the initial scan height.

[0065] Furthermore, the step S202 above, which involves controlling the drone to scan the first identification code and adjusting the drone's position based on the relationship between the scanned first identification code and the drone's position, also includes: Step b2: If the drone's altitude is less than or equal to the second altitude threshold, control the drone to scan the first identifier code and the identifier code combination. Based on the positional relationship between the scanned first identifier code and the drone, and the positional relationship between the scanned second identifier code and the drone, control the drone to adjust its position.

[0066] Specifically, when the drone's altitude is above a first altitude threshold and below a second altitude threshold, the drone is controlled to scan a first identifier code and a combination of identifier codes. Based on the priority of the first and second identifier codes, a target identifier code is determined from the scanned first and second identifier codes. Based on the positional relationship between the target identifier code and the drone, third offset information of the drone relative to the target landing position is obtained. Based on the third offset information, the drone is controlled to adjust its position, and after adjusting its position, the drone continues to descend. For example, if the first identifier code has a higher priority than the second identifier code, the scanned first identifier code is used as the target identifier code, and the drone's position is adjusted according to the positional relationship between the target identifier code and the drone.

[0067] Of course, in practical applications, in addition to determining the target identifier from the first and second identifiers based on priority, the target identifier can also be determined from the first and second identifiers based on their completeness or clarity. Here, we do not limit the method of determining the target identifier.

[0068] In practical applications, the position information of the first identifier and each of the second identifiers is pre-configured, such as the position of the center point of the first identifier and the position of the center point of each second identifier. Based on the position information of the first identifier and the target landing position, the positional relationship of the first identifier relative to the target landing position is configured. Similarly, based on the position information of the second identifiers and the target landing position, the positional relationship of the second identifiers relative to the target landing position is configured. Then, after identifying the target identifier from the scanned first and second identifiers, the current position information of the UAV is obtained. Based on the position information of the target identifier and the current position information of the UAV, the positional relationship between the target identifier and the UAV is obtained. Finally, based on the positional relationship between the target identifier and the target landing position, the third offset information of the UAV relative to the target landing position is obtained.

[0069] Optionally, the third offset information includes at least one of the third horizontal offset of the UAV relative to the target landing position and the third rotation angle offset, which can be adjusted according to the actual situation.

[0070] Specifically, the above-mentioned control of the UAV's position adjustment based on the third offset information includes: controlling the UAV to adjust its horizontal position based on the third horizontal offset of the UAV relative to the target landing position; and controlling the UAV to adjust its rotation angle based on the third rotation angle offset of the UAV relative to the target landing position.

[0071] The drone landing method provided in this embodiment controls the drone to adjust its position by combining the scanned first and second identifier codes when the drone descends to an altitude between a second altitude threshold and a first altitude threshold. Therefore, the accuracy of drone landing can be further improved through visual analysis of the two identifier codes.

[0072] In some optional embodiments, the drone landing method of this application includes: if the drone's altitude is greater than a third altitude threshold, controlling the drone to adjust the lens of the image acquisition device to a zoom lens; if the drone's altitude is less than or equal to the third altitude threshold, controlling the drone to adjust the lens of the image acquisition device to a wide-angle lens.

[0073] The image acquisition device is a camera mounted on the drone.

[0074] Optionally, the third height threshold is 10m, which can be adjusted according to the actual situation, such as 11m, 9m, etc.

[0075] Optionally, the third height threshold is less than or equal to the starting scan height, and the third height threshold is greater than the first height threshold. Further, the third height threshold is greater than or equal to the second height threshold.

[0076] As one alternative implementation, the third altitude threshold is obtained by: acquiring the lens parameters of the image acquisition device of the UAV; and determining the third altitude threshold based on the lens parameters and the size of the second identification code.

[0077] The aforementioned lens parameters include lens type, focal length, angle of view, and other parameters. The third height threshold should ensure that the image acquisition device can scan the complete first identifier or the complete second identifier.

[0078] Specifically, when the drone is at an altitude greater than the third altitude threshold (e.g., between 10m and 30m), the drone is controlled to scan the first identification code in the target through the zoom lens of the image acquisition device.

[0079] Understandably, since the drone is still some distance from the target when its altitude is above the third altitude threshold, using a zoom lens can improve the recognition efficiency and clarity of the identification code, thereby increasing the identification rate.

[0080] Specifically, when the drone is at an altitude less than or equal to a third preset altitude (e.g., below 10m), the drone is controlled to scan the first identification code in the target using the wide-angle lens of the image acquisition device. Understandably, the wide-angle lens increases the field of view and prevents the identification code from being outside the field of view of the image acquisition device.

[0081] The drone landing method provided in this embodiment uses a zoom lens when the drone's altitude is above a third altitude threshold, thus improving the recognition efficiency and clarity of the identification code. When the drone's altitude is below or equal to the third altitude threshold, a wide-angle lens is used, thus increasing the lens's field of view and preventing the identification code from being outside the field of view.

[0082] As a specific application example, taking an initial scan height of 30m, a first height threshold of 1m, and second and third height thresholds of 10m as an example, see [link to example]. Figure 3 The drone landing method of this application mainly includes the following steps: 1. Control the drone to fly along the preset route. Guide the drone to the target area based on real-time situational information from RTK, and control the drone to descend to an altitude of 30m.

[0083] 2. Scan the first identification code in the target using the zoom lens of the image acquisition device.

[0084] 3. Based on the relationship between the scanned first identifier and the drone's position, control the drone to adjust its position.

[0085] 4. Control the drone to descend to a height of 10m.

[0086] 5. Scan the target for the first identification code and the identification code combination using the wide-angle lens of the image acquisition device.

[0087] 6. Based on the relationship between the scanned first identifier and the drone's position, and the relationship between the scanned second identifier and the drone's position, control the drone to adjust its position.

[0088] 7. Control the drone to descend to a height of 1m.

[0089] 8. Scan the target for the first identification code and the identification code combination using the wide-angle lens of the image acquisition device.

[0090] 9. Based on the relationship between the scanned first identifier and the drone's position, and the relationship between the scanned second identifier and the drone's position, control the drone to adjust its position.

[0091] 9. Control the drone to descend to a height of 20cm.

[0092] 10. Scan the second identification code in the target using the wide-angle lens of the image acquisition device.

[0093] 11. Based on the relationship between the scanned second identifier and the drone's position, control the drone to adjust its position.

[0094] 12. Control the drone to descend to the target landing position on the helipad.

[0095] The UAV landing method of this application employs a combination design of a first identifier code and an identifier code combination. It uses the larger first identifier code for long-range coarse positioning and the second identifier code in the identifier code combination for close-range precise positioning. Furthermore, different lenses are used to scan the identifier codes on the target at different altitudes. Different camera models (i.e., the aforementioned image acquisition device) can use different altitudes and different lenses for identification. The same target is applicable to multiple camera models, and the entire control process is stable and smooth. Moreover, at least two large first identifier codes are complementary; even if one first identifier code is obscured, the other first identifier codes can still be used for visual positioning. Similarly, even if part of the second identifier code in the identifier code combination is obscured, the other second identifier codes can still be used to complete the identifier code identification and UAV control process, achieving a UAV landing success rate of up to 95%.

[0096] In addition, the UAV landing method of this application can also use both RTK positioning and identification code visual positioning to achieve UAV positioning in a coordinated manner. The UAV positioning has high reliability and the error can be less than 10cm, which can effectively improve the accuracy of UAV landing.

[0097] This embodiment also provides a drone landing device for implementing the above embodiments and preferred embodiments; details already described will not be repeated. As used below, the term "module" can refer to a combination of software and / or hardware that performs a predetermined function. Although the device described in the following embodiments is preferably implemented in software, hardware implementation, or a combination of software and hardware, is also possible and contemplated. This embodiment provides a drone landing device where a target landing position for the drone is marked with a target. The target includes a combination of identification codes and at least one first identification code. The combination of identification codes includes a plurality of second identification codes, the size of which is smaller than the size of the first identification codes. Figure 4 As shown, it includes: The descent control module 401 is used to control the descent of the UAV when it flies over the target landing position; wherein the target landing position is provided with a first identifier and a combination of identifiers; the combination of identifiers includes multiple second identifiers; the size of the second identifier is smaller than the size of the first identifier; The first position adjustment module 402 is used to control the drone to scan a first identification code when the drone's altitude is greater than a first altitude threshold, and to control the drone to adjust its position based on the relationship between the scanned first identification code and the drone's position, and to control the drone to continue descending; wherein, the first altitude threshold is related to the size of the second identification code; The second position adjustment module 403 is used to control the drone to scan the identification code combination when the drone's altitude is less than or equal to the first altitude threshold, and to control the drone to adjust its position based on the relationship between the scanned second identification code and the drone's position, and to control the drone to descend to the target landing position.

[0098] In some alternative implementations, the descent control module 401 includes: The information acquisition unit is used to acquire real-time situational information of the UAV; The flight control unit is used to control the UAV to fly to the airspace above the target landing position based on real-time situational information; The descent control unit is used to control the drone to descend when the horizontal position error of the drone relative to the target landing position is less than a preset horizontal error and the drone's altitude is less than the initial scanning altitude; wherein, the initial scanning altitude is greater than a first altitude threshold and the initial scanning altitude is related to the size of the first identification code.

[0099] In some alternative implementations, the second identifier is of a different type than the first identifier, and there are differences between the various second identifiers in the identifier combination.

[0100] In some alternative implementations, the number of first identifiers is at least two, and there are differences between the various first identifiers.

[0101] In some alternative implementations, the first position adjustment module 402 includes: The first position adjustment unit is used to control the drone to scan the first identification code and the identification code combination if the drone's altitude is less than or equal to the second altitude threshold. Based on the positional relationship between the scanned first identification code and the drone, and the positional relationship between the scanned second identification code and the drone, the unit controls the drone to adjust its position. The second altitude threshold is greater than the first altitude threshold and is related to the size of the first identification code and the size of the second identification code.

[0102] In some optional embodiments, the drone landing device of this application further includes: The first lens switching module is used to control the drone to adjust the lens of the image acquisition device to a zoom lens if the drone's altitude is greater than the third altitude threshold. The second lens switching module is used to control the drone to adjust the lens of the image acquisition device to a wide-angle lens if the drone's altitude is less than or equal to the third altitude threshold.

[0103] In some optional embodiments, the drone landing device of this application further includes: The parameter acquisition module is used to acquire the lens parameters of the image acquisition device of the UAV. The height analysis module is used to determine the third height threshold based on lens parameters and the size of the second identifier code.

[0104] The drone landing device provided in this embodiment of the invention can execute the drone landing method provided in any embodiment of the invention, and has the corresponding functional modules and beneficial effects for executing the method. Further functional descriptions of the various modules and units described above are the same as in the corresponding embodiments described above, and will not be repeated here.

[0105] This embodiment also provides a drone, which includes: a drone body and a flight control motherboard; wherein, the drone body includes an image acquisition device, such as a drone-mounted camera, etc. The drone body also includes drone propellers, drone motors, a positioning device, an obstacle avoidance device, etc. The positioning device includes a GPS antenna, an RTK antenna, etc. The obstacle avoidance device includes various sensors such as laser sensors and radar sensors.

[0106] Specifically, the flight control motherboard is used to execute the UAV landing method in any of the above embodiments. The flight control motherboard may include a processor (e.g., a central processing unit, a graphics processing unit, etc.), which can perform various appropriate actions and processes according to a program stored in read-only memory (ROM) (such as flight control firmware) or a program loaded from memory into random access memory (RAM). The RAM also stores various programs and data required for the operation of the flight control motherboard. The processor, ROM, and RAM are interconnected. The flight control motherboard also has input / output (I / O) interfaces for connecting the flight control motherboard to various components or other devices on the UAV body.

[0107] Specifically, according to embodiments of the present invention, the process described above with reference to the flowchart can be implemented as a flight control firmware program. This flight control firmware program contains program code for performing the methods shown in the flowchart. In such an embodiment, when the flight control firmware program is executed by a processor, it performs the functions defined above in the UAV landing method of the embodiments of the present invention.

[0108] The flight controller motherboard described above is merely an example and should not impose any limitations on the functionality and scope of use of the embodiments of the present invention.

[0109] This invention also provides a computer-readable storage medium. The methods described above according to embodiments of the invention can be implemented in hardware or firmware, or implemented as computer code that can be recorded on a storage medium, or implemented as computer code downloaded via a network and originally stored on a remote storage medium or a non-transitory machine-readable storage medium and then stored on a local storage medium. Thus, the methods described herein can be processed by software stored on a storage medium using a general-purpose computer, a dedicated processor, or programmable or dedicated hardware. The storage medium can be a magnetic disk, optical disk, read-only memory, random access memory, flash memory, hard disk, or solid-state drive, etc.; further, the storage medium can also include combinations of the above types of memory. It is understood that computers, processors, microprocessor controllers, or programmable hardware include storage components capable of storing or receiving software or computer code. When the software or computer code is accessed and executed by the computer, processor, or hardware, the UAV landing method shown in the above embodiments is implemented.

[0110] A portion of this invention can be applied as a computer program product, such as computer program instructions, which, when executed by a computer, can invoke or provide the methods and / or technical solutions according to the invention through the operation of the computer. Those skilled in the art will understand that the forms in which computer program instructions exist in a computer-readable medium include, but are not limited to, source files, executable files, installation package files, etc. Correspondingly, the ways in which computer program instructions are executed by a computer include, but are not limited to: the computer directly executing the instructions, or the computer compiling the instructions and then executing the corresponding compiled program, or the computer reading and executing the instructions, or the computer reading and installing the instructions and then executing the corresponding installed program. Here, the computer-readable medium can be any available computer-readable storage medium or communication medium accessible to a computer.

[0111] Although embodiments of the invention have been described in conjunction with the accompanying drawings, those skilled in the art can make various modifications and variations without departing from the spirit and scope of the invention, and such modifications and variations all fall within the scope defined by the appended claims.

Claims

1. A method for landing an unmanned aerial vehicle (UAV), characterized in that, The method includes: When the drone flies over the target landing location, it is controlled to descend; wherein the target landing location is provided with a first identifier and a combination of identifiers; the combination of identifiers includes multiple second identifiers; the size of the second identifier is smaller than the size of the first identifier; When the drone's altitude is greater than a first altitude threshold, the drone is controlled to scan the first identification code. Based on the relationship between the scanned first identification code and the drone's position, the drone is controlled to adjust its position and continue to descend. The first altitude threshold is related to the size of the second identification code. When the drone's altitude is less than or equal to the first altitude threshold, the drone is controlled to scan the identification code combination. Based on the relationship between the scanned second identification code and the drone's position, the drone is controlled to adjust its position and descend to the target landing position.

2. The UAV landing method according to claim 1, characterized in that, The second identifier is of a different type than the first identifier, and there are differences between the individual second identifiers in the identifier combination.

3. The UAV landing method according to claim 1, characterized in that, The number of the first identifier is at least two, and there are differences between the various first identifiers.

4. The UAV landing method according to claim 1, characterized in that, The step of controlling the drone to descend when it flies over the target landing location includes: Obtain the real-time situational information of the UAV; Based on the real-time situational information, the drone is controlled to fly to the airspace above the target landing location; When the horizontal position error of the drone relative to the target landing position is less than a preset horizontal error, and the altitude of the drone is less than the initial scanning altitude, the drone is controlled to descend; wherein, the initial scanning altitude is greater than the first altitude threshold, and the initial scanning altitude is related to the size of the first identification code.

5. The unmanned aerial vehicle landing method according to claim 1, characterized in that, The step of controlling the drone to scan the first identification code and adjusting the drone's position based on the relationship between the scanned first identification code and the drone's position includes: If the drone's altitude is less than or equal to the second altitude threshold, the drone is controlled to scan the first identifier code and the identifier code combination. Based on the positional relationship between the scanned first identifier code and the drone, and the positional relationship between the scanned second identifier code and the drone, the drone is controlled to adjust its position. The second altitude threshold is greater than the first altitude threshold, and the second altitude threshold is related to the size of the first identifier code and the size of the second identifier code.

6. The unmanned aerial vehicle landing method according to any one of claims 1 to 5, characterized in that, The method further includes: If the drone is at an altitude greater than the third altitude threshold, then control the drone to adjust the lens of the image acquisition device to a zoom lens; If the drone's altitude is less than or equal to the third altitude threshold, then the drone is controlled to adjust the lens of the image acquisition device to a wide-angle lens.

7. The unmanned aerial vehicle landing method according to claim 6, characterized in that, The third height threshold is obtained in the following way: Obtain the lens parameters of the image acquisition device of the UAV; The third height threshold is determined based on the lens parameters and the size of the second identification code.

8. A drone, characterized in that, include: The main body of the drone; A flight control motherboard for executing the drone landing method according to any one of claims 1 to 7.

9. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores computer instructions for causing the computer to execute the drone landing method according to any one of claims 1 to 7.

10. A computer program product, characterized in that, Includes computer instructions for causing a computer to execute the drone landing method according to any one of claims 1 to 7.

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