A device and method for rapid automatic focusing of a hyperspectral imager of a drone

Abstract

This application provides a device and method for rapid autofocus of a hyperspectral imager for unmanned aerial vehicles (UAVs). The device includes a flight device, a housing, a data acquisition and control module, an image acquisition element, a hyperspectral imaging element, and an autofocus lens. The data acquisition and control module controls the image acquisition element to move into the optical path of the autofocus lens to acquire image information of the target, and controls the autofocus lens to automatically focus based on the image information to achieve autofocus operation. Since the image acquisition element and the hyperspectral imaging element share a single autofocus lens, i.e., they are confocal, it can be considered that the autofocus lens adapted to the hyperspectral imaging element has completed focusing. At this time, the hyperspectral imaging element is controlled to move into the optical path of the autofocus lens to acquire the spectral image of the target, thus achieving spectral imaging. The device of this application is not only simple in structure but also enables automatic focusing operation, and the entire focusing operation is fast and accurate.

Description

Technical Field

[0001] This application relates to the field of hyperspectral focusing technology, and in particular to a device and method for rapid automatic focusing of a hyperspectral imager for unmanned aerial vehicles. Background Technology

[0002] UAV hyperspectral imagers acquire both spatial and continuous spectral information of targets simultaneously to precisely characterize the reflection, transmission, and absorption characteristics of ground objects in different electromagnetic wave bands, thereby enabling the identification and analysis of the target material composition, structure, and state.

[0003] Before testing, the hyperspectral imager of the UAV needs to be focused in advance to acquire image data with good imaging quality. However, the image resolution will vary at different flight altitudes. Therefore, manual focusing on the ground is required in advance according to the flight altitude, which is not only time-consuming and laborious but also has poor focusing accuracy. Summary of the Invention

[0004] The purpose of this application is to provide a device and method for fast autofocus of a hyperspectral imager for unmanned aerial vehicles (UAVs), aiming to solve the problem of how to achieve autofocus of a hyperspectral imager for UAVs.

[0005] In a first aspect, embodiments of this application provide a device for rapid autofocus of a hyperspectral imager for an unmanned aerial vehicle (UAV), including a flight device and a device housing, a data acquisition and control module, an image acquisition element, a hyperspectral imaging element, and an autofocus lens mounted on the flight device;

[0006] Both the image acquisition element and the hyperspectral imaging element are movably disposed within the device housing, the autofocus lens is disposed on the device housing, and the data acquisition and control module is electrically connected to the flight equipment, the autofocus lens, the image acquisition element, and the hyperspectral imaging element, respectively.

[0007] The data acquisition and control module is used to control the image acquisition element to move to the optical path of the autofocus lens to acquire image information of the target. The data acquisition and control module is used to control the autofocus lens to focus according to the image information, and after focusing, control the hyperspectral imaging element to move to the optical path of the autofocus lens to acquire spectral image of the target.

[0008] In some embodiments, the image plane of the image acquisition element and the image plane of the hyperspectral imaging element are aligned along the optical path direction of the autofocus lens.

[0009] In some embodiments, the device housing is provided with a drive component electrically connected to the data acquisition and control module. The drive component is drively connected to the hyperspectral imaging element and the image acquisition element, and is used to drive either the hyperspectral imaging element or the image acquisition element to move onto the optical path of the autofocus lens.

[0010] In some embodiments, the driving element includes a drive motor;

[0011] And / or, the device housing is provided with a slide rail extending along the moving direction of the image acquisition element, and both the image acquisition element and the hyperspectral imaging element are slidably disposed on the slide rail.

[0012] In some embodiments, the data acquisition and control module is disposed within the device housing;

[0013] And / or, the data acquisition and control module is configured to acquire the altitude information of the device for rapid autofocus of the UAV hyperspectral imager relative to the target, and control the autofocus lens to initially focus based on the altitude information.

[0014] In some embodiments, the image acquisition element is an RGB camera;

[0015] And / or, the hyperspectral imaging element is a hyperspectral camera;

[0016] And / or, the flight equipment is a drone.

[0017] Secondly, this application provides a method for autofocusing using a device for rapid autofocusing of a UAV hyperspectral imager, comprising the following steps:

[0018] The flight equipment is controlled to hover at a preset altitude.

[0019] The data acquisition and control module controls the image acquisition element to move to the optical path of the autofocus lens, so as to acquire image information of the target through the image acquisition element;

[0020] The data acquisition and control module controls the autofocus lens to focus based on the image information.

[0021] The data acquisition and control module is used to control the hyperspectral imaging element to move into the optical path of the autofocus lens after focusing is completed, and to control the flight device to fly so as to acquire the spectral image of the target through the hyperspectral imaging element.

[0022] In some embodiments, the method by which the data acquisition and control module controls the autofocus lens to focus based on the image information includes:

[0023] The start and stop of the image acquisition operation of the image acquisition element are controlled according to the clarity of the currently acquired image information;

[0024] If the resolution is greater than or equal to the preset resolution, the image acquisition element is controlled by the data acquisition control module to stop image acquisition without the need for focusing.

[0025] If the resolution is less than the preset resolution, the autofocus lens is controlled to focus, and then the image acquisition element is controlled to continue acquiring images until the resolution of the acquired image information is greater than or equal to the preset resolution. Then, the image acquisition element is controlled to stop acquiring images, and the focusing operation is completed.

[0026] In some embodiments, the data acquisition and control module is further configured to acquire the altitude information of the device for rapid autofocus of the UAV hyperspectral imager relative to the target, and control the autofocus lens to perform preliminary focusing based on the altitude information.

[0027] In some embodiments, the method of controlling the autofocus lens to perform preliminary focusing based on the height information includes:

[0028] The focusing pulse value is calculated based on the distance-focal length model and the height information.

[0029] The autofocus lens is controlled to perform initial focusing based on the pulse value.

[0030] The beneficial effects of this invention are:

[0031] This application provides a device and method for rapid autofocus of a hyperspectral imager for an unmanned aerial vehicle (UAV). The device includes a flight device and a housing, a data acquisition and control module, an image acquisition element, a hyperspectral imaging element, and an autofocus lens mounted on the flight device. By movably housing both the image acquisition element and the hyperspectral imaging element within the housing, either the image acquisition element or the hyperspectral imaging element can be automatically moved into the optical path of the autofocus lens under the control of the data acquisition and control module to perform the corresponding image acquisition operation. The autofocus lens is mounted on the housing and is used to achieve autofocus. When focusing is required, the data acquisition and control module controls the image acquisition element to move into the optical path of the autofocus lens to acquire image information of the target. Based on the image information, the data acquisition and control module controls the autofocus lens to automatically focus, thus enabling automatic focusing. Since the image acquisition element and the hyperspectral imaging element share a single autofocus lens (i.e., they are confocal), the autofocus lens adapted to the hyperspectral imaging element can be considered to have completed focusing. At this point, the hyperspectral imaging element can be controlled to move into the optical path of the autofocus lens to acquire the spectral image of the target, achieving spectral imaging. The device of this application is not only simple in structure but also enables automatic focusing, and the entire focusing operation is fast and accurate. Attached Figure Description

[0032] To more clearly illustrate the technical solutions of the embodiments of this application, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0033] Figure 1 This is a schematic diagram of the hyperspectral focusing device shown in the embodiment of this application;

[0034] Figure 2 This is a flowchart illustrating the focusing method using a hyperspectral focusing device as shown in the embodiments of this application;

[0035] Figure 3 This is an overall logic flowchart of the focusing method using a hyperspectral focusing device as shown in the embodiments of this application.

[0036] Figure label:

[0037] 100. Flight equipment; 200. Equipment housing; 300. Data acquisition and control module; 400. Image acquisition element; 500. Hyperspectral imaging element; 600. Autofocus lens; 700. Drive components. Detailed Implementation

[0038] In the embodiments of this application, the terms "first," "second," "third," "fourth," "fifth," and "sixth" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined with "first," "second," "third," "fourth," "fifth," and "sixth" may explicitly or implicitly include one or more of that feature.

[0039] In embodiments of this application, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element.

[0040] Reference Figure 1 As shown, this application provides a device for rapid autofocus of a UAV hyperspectral imager, including a flight device 100 and a device housing 200, a data acquisition and control module 300, an image acquisition element 400, a hyperspectral imaging element 500, and an autofocus lens 600 mounted on the flight device 100.

[0041] Both the image acquisition element 400 and the hyperspectral imaging element 500 are movably housed within the device housing 200. The autofocus lens 600 is mounted on the device housing 200. The data acquisition and control module 300 is electrically connected to the flight equipment 100, the autofocus lens 600, the image acquisition element 400, and the hyperspectral imaging element 500, respectively.

[0042] The data acquisition and control module 300 is used to control the image acquisition element 400 to move onto the optical path of the autofocus lens 600 to acquire image information of the target. The data acquisition and control module 300 is used to control the autofocus lens 600 to focus according to the image information, and after focusing, it controls the hyperspectral imaging element 500 to move onto the optical path of the autofocus lens 600 to acquire the spectral image of the target.

[0043] In practice, the flight equipment 100 is used to carry the equipment housing 200, data acquisition and control module 300, image acquisition element 400, hyperspectral imaging element 500 and autofocus lens 600 to the required altitude, and then acquires the target image information through hyperspectral imaging element 500 and image acquisition element 400.

[0044] Both the image acquisition element 400 and the hyperspectral imaging element 500 are movably disposed within the device housing 200, thereby allowing either the image acquisition element 400 or the hyperspectral imaging element 500 to be moved to the optical path of the autofocus lens 600 as needed.

[0045] For example, when focusing is required, the data acquisition and control module 300 controls the image acquisition element 400 to move into the optical path of the autofocus lens 600. At this time, the autofocus lens 600 acts as the lens of the image acquisition element 400, focusing external light onto the image plane of the image acquisition element 400 to form color image information. Then, the autofocus lens 600 can be controlled to focus based on the image information.

[0046] Specifically, when the image information has high clarity, such as reaching a preset clarity value, the focal length is considered appropriate, and no focus adjustment is needed; that is, no focusing or refocusing is required. When the image information has low clarity, such as below the preset clarity value, the focal length setting is inappropriate. The autofocus lens 600 needs to be controlled to focus, and then the image acquisition element 400 acquires image information. Clarity analysis is then performed. If the clarity is still below the preset clarity value, the autofocus lens 600's focusing operation is repeated until the acquired image information's clarity reaches the preset clarity value. At this point, the focusing operation is considered complete, and the image acquisition element 400's acquisition operation can be stopped.

[0047] After the focusing operation is completed, the data acquisition control module 300 controls the image acquisition element 400 to move outside the optical path and moves the hyperspectral imaging element 500 into the optical path of the autofocus lens 600. At this time, the autofocus lens 600 acts as the lens of the hyperspectral imaging element 500, focusing external light onto the image plane of the hyperspectral imaging element 500. At this time, the flight device 100 flies to acquire spectral images and realize flight scanning imaging.

[0048] In this embodiment, since the image acquisition element 400 and the hyperspectral imaging element 500 share an autofocus lens 600, i.e., they are cofocused, the image information acquired by the image acquisition element 400 can be used to adjust the focal length of the autofocus lens 600. At this point, it is considered that the autofocus lens 600 adapted to the hyperspectral imaging element 500 has completed precise focusing. This enables automatic focusing without having to manually focus the flight device 100. This is not only convenient and time-saving, but also has high focusing accuracy. It allows the flight device 100 to automatically focus in real time according to the flight altitude during flight, ensuring good imaging effect at any flight altitude. Furthermore, the flight device 100 can avoid being limited by the flight altitude of the usage scenario.

[0049] For example, the Auto-Focus Lens 600 (AF lens) is an optical system that automatically adjusts the position of the lens group through an electronically controlled drive mechanism without the need for manual rotation of the focusing ring, so that the subject can be clearly imaged on the image plane.

[0050] Specifically, the autofocus lens 600 typically includes an optical lens group, a focusing drive mechanism, a position feedback sensor, and control circuitry. The optical lens group is used for imaging, and the focusing drive mechanism is electrically connected to the data acquisition and control module 300, used to drive the optical lens group to move under the control of the data acquisition and control module. The focusing drive mechanism is typically a voice coil motor or a stepper motor. Position sensors, such as magnetic scales, Hall effect sensors, or photoelectric encoders, are used to detect the position of the optical lens group, and their position is electrically connected to the data acquisition and control module 300 via the control circuitry.

[0051] The rapid autofocus device for the UAV hyperspectral imager in this embodiment includes a flight device 100 and a device housing 200, a data acquisition and control module 300, an image acquisition element 400, a hyperspectral imaging element 500, and an autofocus lens 600 mounted on the flight device 100. By movably housing both the image acquisition element 400 and the hyperspectral imaging element 500 within the device housing 200, either the image acquisition element 400 or the hyperspectral imaging element 500 can automatically move under the control of the data acquisition and control module 300 into the optical path of the autofocus lens 600 to perform the corresponding image acquisition operation. The autofocus lens 600 is mounted on the device housing 200 and is used for autofocus. When focusing is required, the data acquisition and control module 300 controls the image acquisition element 400 to move into the optical path of the autofocus lens 600 to acquire image information of the target. The data acquisition and control module 300 controls the autofocus lens 600 to automatically focus based on the image information, thus enabling automatic focusing operation of the autofocus lens 600. Since the image acquisition element 400 and the hyperspectral imaging element 500 share the same autofocus lens 600, meaning they are co-focal, it can be considered that the autofocus lens 600 adapted to the hyperspectral imaging element 500 has completed focusing. At this time, the hyperspectral imaging element 500 can be controlled to move into the optical path of the autofocus lens 600 to acquire the spectral image of the target, achieving spectral imaging. The device in this embodiment is not only simple in structure but also enables automatic focusing operation, and the entire focusing operation is fast and accurate.

[0052] Reference Figure 1As shown, in some embodiments, the image planes of the image acquisition element 400 and the hyperspectral imaging element 500 are aligned along the optical path of the autofocus lens 600. This arrangement ensures that no focus shift occurs whether the image acquisition element 400 or the hyperspectral imaging element 500 moves onto the optical path of the autofocus lens 600. In other words, the focal length of the autofocus lens 600 is suitable for both the image acquisition element 400 and the hyperspectral imaging element 500, allowing for repeated focusing to improve imaging performance, simplify focusing operations, and ensure good consistency in the overall focusing effect.

[0053] Reference Figure 1 As shown, in some embodiments, a drive unit 700 electrically connected to the data acquisition and control module 300 is provided inside the device housing 200. The drive unit 700 is connected to the hyperspectral imaging element 500 and the image acquisition element 400 for driving either the hyperspectral imaging element 500 or the image acquisition element 400 to move to the optical path of the autofocus lens 600, so as to realize the corresponding focusing operation or the corresponding spectral image acquisition operation.

[0054] When the driving unit 700 moves the image acquisition element 400 onto the optical path, the image information acquired by the image acquisition element 400 can control the autofocus lens 600 to focus, and the autofocus lens 600 can then be used for focusing operations. When the driving unit 700 moves the hyperspectral imaging element 500 onto the optical path, the hyperspectral imaging element 500 can acquire spectral information, and the autofocus lens 600 can then be used for imaging.

[0055] In practice, the hyperspectral imaging element 500 and the image acquisition element 400 can be automatically driven by the drive unit 700 to replace manual drive, which can save manpower and facilitate automatic movement during flight to achieve automatic focusing.

[0056] Specifically, the driving unit 700 may include a driving motor that can simultaneously drive the hyperspectral imaging element 500 and the image acquisition element 400 to move synchronously, moving one of them onto the optical path of the autofocus lens 600, thus achieving the purpose of alternating entry into the optical path. Alternatively, the driving unit 700 may include two driving motors, which can drive the corresponding image acquisition element 400 and hyperspectral imaging element 500 onto the optical path as needed.

[0057] In some embodiments, a slide rail extending along the moving direction of the image acquisition element 400 may be provided inside the device housing 200. Both the image acquisition element 400 and the hyperspectral imaging element 500 are slidably disposed on the slide rail, thereby achieving a guiding effect on the movement of the image acquisition element 400 and the hyperspectral imaging element 500, preventing the image acquisition element 400 and the hyperspectral imaging element 500 from deviating during movement and affecting the final focusing effect.

[0058] For example, the slide rail can be snapped or screwed into the device housing 200.

[0059] Reference Figure 1 As shown, in some embodiments, the data acquisition and control module 300 is disposed inside the device housing 200 so as to utilize the internal space of the device housing 200 to accommodate the data acquisition and control module 300, thereby achieving rational utilization of the internal space and effectively protecting the data acquisition and control module 300.

[0060] For example, the data acquisition and control module 300 can be screwed or snapped into the device housing 200.

[0061] In some embodiments, the data acquisition control module 300 is configured to acquire the altitude information of the device for rapid autofocus of the UAV hyperspectral imager relative to the target, and control the autofocus lens 600 to perform preliminary focusing based on the altitude information.

[0062] In other words, before using the image information acquired by the image acquisition element 400 to control the autofocus lens 600 for precise focusing, the data acquisition and control module 300 can acquire the altitude information of the UAV hyperspectral imager's fast autofocus device relative to the target, and control the autofocus lens 600 for preliminary focusing based on the altitude information, i.e., coarse focusing. Precise focusing is then performed after the preliminary focusing; that is, by combining rapid coarse focusing with short-distance fine focusing, focusing can be faster, more accurate, and with less error.

[0063] In practice, a distance-focal length model can be built into the data acquisition and control module 300. The focusing pulse value is calculated by comparing the distance-focal length model with the height information, and then the autofocus lens 600 is controlled to perform preliminary focusing based on the pulse value.

[0064] Furthermore, in this embodiment, the height information can be measured directly using the data acquisition and control module 300 without the need for a laser rangefinder, thus saving costs and facilitating miniaturization.

[0065] In some embodiments, the image acquisition element 400 is an RGB camera, which is a visible light color camera that simultaneously acquires a color image through three color filter pixels: red, green, and blue, and outputs a "true color" photo or video familiar to the human eye.

[0066] Furthermore, since the image acquired by the image acquisition element 400 is a complete "true color" photograph or video in a single imaging session, while the image acquired by the hyperspectral imaging element 500 is a line in a single imaging session, it is not possible to directly acquire the image using the hyperspectral imaging element 500 and then focus based on the image information. Instead, the image acquisition element 400 needs to acquire the image and then focus based on the image information before the hyperspectral imaging element 500 performs multiple scans to finally obtain the spectral image.

[0067] For example, the hyperspectral imaging element 500 is a hyperspectral camera, or it can also be a hyperspectral imager, used to acquire the spatial and continuous spectral information of the target, so as to finely characterize the reflection, transmission and absorption characteristics of the ground object in different bands of electromagnetic waves, thereby realizing the identification and analysis of the material composition, structure and state of the target.

[0068] For example, the flight device 100 is a drone, or it may be other aircraft, used to carry the entire device at high altitude so that the hyperspectral imaging element 500 can perform flight scanning imaging.

[0069] Reference Figure 2 and Figure 3 As shown, this application provides a method for autofocusing using a device for rapid autofocusing of a UAV hyperspectral imager, comprising the following steps:

[0070] S101, Control the flight equipment 100 to fly to the preset altitude and then hover;

[0071] S102, the data acquisition control module 300 controls the image acquisition element 400 to move to the optical path of the autofocus lens 600, so as to acquire the image information of the target through the image acquisition element 400;

[0072] S103, Data acquisition and control module 300 controls autofocus lens 600 to focus based on image information;

[0073] S104, the data acquisition and control module 300 is used to control the hyperspectral imaging element 500 to move to the optical path of the autofocus lens 600 after focusing is completed, and to control the flight device 100 to fly so as to acquire the spectral image of the target through the hyperspectral imaging element 500.

[0074] In practice, when focusing is required, the flight device 100 can be controlled to fly to a preset altitude and hover. Then, the image acquisition element 400 is controlled to acquire images. Based on the acquired image information, the autofocus lens 600 is controlled to focus. Once focusing is complete, the entire device can be considered to have finished focusing. Then, the flight device 100 flies again and the hyperspectral imaging element 500 performs flight scanning to form a spectral image.

[0075] The specific structure and implementation principle of the device for fast autofocus of the UAV hyperspectral imager in this embodiment are the same as those of the device for fast autofocus of the UAV hyperspectral imager provided in the above embodiment, and can bring the same or similar technical effects. They will not be described in detail here, but can be referred to the description of the above embodiment.

[0076] Reference Figure 3 As shown, in specific implementation, the method by which the data acquisition and control module 300 controls the autofocus lens 600 to focus based on image information includes:

[0077] The start and stop of the acquisition operation of the image acquisition element 400 are controlled according to the clarity of the currently acquired image information;

[0078] If the resolution is greater than or equal to the preset resolution, the image acquisition element 400 is controlled by the data acquisition control module 300 to stop image acquisition, and no focusing is required;

[0079] If the resolution is less than the preset resolution, the autofocus lens 600 is controlled to focus, and then the image acquisition element 400 is controlled to continue to acquire images until the resolution of the acquired image information is greater than or equal to the preset resolution. Then, the image acquisition element 400 is controlled to stop acquiring images, and the focusing operation is completed.

[0080] Reference Figure 3 As shown, in practical implementation, the appropriate focal length can be determined based on the sharpness of the image information. For example, when the image information has high sharpness, such as reaching a preset sharpness value, the focal length is considered appropriate, and no focal length adjustment is required. When the image information has low sharpness, such as being lower than the preset sharpness value, the focal length is inappropriate. In this case, the autofocus lens 600 needs to be controlled to focus, and then the image acquisition element 400 acquires image information and performs sharpness analysis. If the sharpness is still lower than the preset sharpness value, the autofocus lens 600's focusing operation is repeated until the sharpness of the acquired image information reaches the preset sharpness value. At this point, the focusing operation is considered complete, and the image acquisition element 400's acquisition operation can be stopped.

[0081] Reference Figure 3As shown, in some embodiments, the data acquisition and control module 300 is also configured to acquire the altitude information of the device for rapid autofocus of the UAV hyperspectral imager relative to the target, and control the autofocus lens 600 to perform preliminary focusing based on the altitude information.

[0082] In other words, the data acquisition and control module 300 can collect the altitude information of the UAV's hyperspectral imager's fast autofocus device relative to the target, and control the autofocus lens 600 to perform preliminary focusing based on the altitude information, i.e., coarse focusing. After preliminary focusing, the image information collected by the image acquisition element 400 is used to perform precise focusing on the autofocus lens 600. That is, by combining rapid coarse focusing with short-distance fine focusing, focusing can be faster, more accurate, and with smaller errors.

[0083] Reference Figure 3 As shown, in some embodiments, the method for controlling the autofocus lens 600 to perform preliminary focusing based on altitude information includes:

[0084] The focusing pulse value is calculated based on the distance-focal-length model and altitude information.

[0085] The autofocus lens 600 is initially focused based on the pulse value.

[0086] In practice, when the autofocus lens 600 is focused according to the pulse value, each pulse value corresponds to a tiny displacement (e.g., one pulse value corresponds to 0.005mm). The data acquisition and control module 300 accurately calculates the movement displacement of the optical lens group by counting the pulse values, and controls the focusing drive mechanism to control the optical lens group to move precisely by the required movement displacement, thereby achieving micron-level focusing. Typically, the focusing accuracy can reach 0.02mm.

[0087] In the description of the embodiments of this application, specific features, structures, materials or characteristics may be combined in any suitable manner in one or more embodiments or examples.

[0088] The above are merely specific embodiments of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A device for rapid automatic focusing of a hyperspectral imager for unmanned aerial vehicles (UAVs), characterized in that, It includes a flight device (100) and a device housing (200), a data acquisition and control module (300), an image acquisition element (400), a hyperspectral imaging element (500), and an autofocus lens (600) mounted on the flight device (100). Both the image acquisition element (400) and the hyperspectral imaging element (500) are movably disposed within the device housing (200). A drive unit (700) electrically connected to the data acquisition control module (300) is disposed within the device housing (200). The drive unit (700) is respectively connected to the hyperspectral imaging element (500) and the image acquisition element (400) for driving either the hyperspectral imaging element (500) or the image acquisition element (400) to move onto the optical path of the autofocus lens (600). The drive unit (700) includes two drive motors, which are respectively used to drive the corresponding image acquisition element (400) and hyperspectral imaging element (500) to move onto the optical path. The autofocus lens (600) is mounted on the device housing (200), and the data acquisition and control module (300) is electrically connected to the flight equipment (100), the autofocus lens (600), the image acquisition element (400), and the hyperspectral imaging element (500). The data acquisition and control module (300) is used to first control the flight device (100) to fly to a preset altitude and hover. In the hovering state of the flight device, the image acquisition element (400) is controlled to move to the optical path of the autofocus lens (600) to acquire the image information of the target. The data acquisition and control module (300) is used to control the autofocus lens (600) to focus according to the image information. After focusing is completed, the image acquisition element (400) is controlled to move outside the optical path, and the hyperspectral imaging element (500) is controlled to move to the optical path of the autofocus lens (600). Then, the flight device (100) is controlled to fly so as to acquire the spectral image of the target through the hyperspectral imaging element (500).

2. The device for rapid autofocus of a UAV hyperspectral imager according to claim 1, characterized in that, Along the optical path of the autofocus lens (600), the image plane of the image acquisition element (400) and the image plane of the hyperspectral imaging element (500) are aligned.

3. The device for rapid autofocus of a UAV hyperspectral imager according to claim 1, characterized in that, The device housing (200) is provided with a slide rail extending along the moving direction of the image acquisition element (400), and both the image acquisition element (400) and the hyperspectral imaging element (500) are slidably disposed on the slide rail.

4. The device for rapid autofocus of a UAV hyperspectral imager according to claim 1, characterized in that, The data acquisition and control module (300) is disposed inside the device housing (200); And / or, the data acquisition control module (300) is configured to acquire the altitude information of the device for rapid autofocus of the UAV hyperspectral imager relative to the target, and control the autofocus lens (600) to initially focus based on the altitude information.

5. The device for rapid autofocus of a UAV hyperspectral imager according to claim 1, characterized in that, The image acquisition element (400) is an RGB camera; And / or, the hyperspectral imaging element (500) is a hyperspectral camera; And / or, the flight device (100) is a drone.

6. A method for autofocusing using the device for rapid autofocusing of a UAV hyperspectral imager as described in any one of claims 1 to 5, characterized in that, Includes the following steps: The flight equipment is controlled to hover at a preset altitude. The data acquisition and control module controls the image acquisition element to move to the optical path of the autofocus lens, so as to acquire image information of the target through the image acquisition element; The data acquisition and control module controls the autofocus lens to focus based on the image information. The data acquisition and control module is used to control the hyperspectral imaging element to move into the optical path of the autofocus lens after focusing is completed, and to control the flight device to fly so as to acquire the spectral image of the target through the hyperspectral imaging element.

7. The method according to claim 6, characterized in that, The method by which the data acquisition and control module controls the autofocus lens to focus based on the image information includes: The start and stop of the image acquisition operation of the image acquisition element are controlled according to the clarity of the currently acquired image information; If the resolution is greater than or equal to the preset resolution, the image acquisition element is controlled by the data acquisition control module to stop image acquisition without the need for focusing. If the resolution is less than the preset resolution, the autofocus lens is controlled to focus, and then the image acquisition element is controlled to continue acquiring images until the resolution of the acquired image information is greater than or equal to the preset resolution. Then, the image acquisition element is controlled to stop acquiring images, and the focusing operation is completed.

8. The method according to claim 6, characterized in that, Before the step of the data acquisition and control module controlling the autofocus lens to focus based on the image information, the method further includes: The data acquisition and control module acquires the altitude information of the UAV hyperspectral imager's rapid autofocus device relative to the target. The data acquisition and control module controls the autofocus lens to perform preliminary focusing based on the height information.

9. The method according to claim 8, characterized in that, The method by which the data acquisition and control module controls the autofocus lens to perform preliminary focusing based on the height information includes: The focusing pulse value is calculated based on the distance-focal length model and the height information. The autofocus lens is controlled to perform initial focusing based on the pulse value.

Images