View field self-stabilization and self-adjustment hyperspectral camera system and control method

Abstract

The invention discloses a field-of-view self-stabilization and self-adjustment hyperspectral camera system and a control method, and relates to the technical field of hyperspectral imaging. The system comprises a first imaging lens group, a movable slit, a two-dimensional linear driver, a slit outer layer light shield, a collimating lens group, a light splitting element, a second imaging lens group, an area array image sensor, an attitude sensor and a control acquisition circuit. Angle disturbance is obtained in real time, two-dimensional compensation displacement of the slit is calculated to drive the slit to move reversely, field-of-view collection is kept basically constant, collection is triggered according to a set rhythm, slit position and attitude data are recorded synchronously, and the pre-calibrated slit position and mapping of original coordinates and ideal coordinates are combined, so that field-of-view collection is completed. Geometric transformation and resampling dynamic correction are carried out on view field inclination aberration and spectrum bending aberration generated along with slit position changes, the environmental adaptability and reliability are improved, a hyperspectral data cube with accurate space coordinates and a stable spectrum curve is output, and the method is suitable for unmanned aerial vehicle-mounted hyperspectral remote sensing.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of hyperspectral imaging, in particular to a hyperspectral camera system with self-stabilized and self-adjusted field of view and a control method. BACKGROUND

[0002] The unmanned aerial hyperspectral imaging technology is an important remote sensing means for obtaining continuous and fine spectral information of ground objects through a hyperspectral sensor mounted on an unmanned aerial vehicle platform. Field of view stabilization is the basis for the application of this technology, which directly determines the clarity of the acquired images and the accuracy of the spectral data, and is a key prerequisite for quantitative analysis in the fields of environmental monitoring, precision agriculture, resource exploration, etc. If the field of view is unstable, it will lead to image blurring, pixel mixing and spectral distortion, making the acquired data unable to be effectively utilized, and seriously affecting the accuracy of decision-making and the operation effect. Therefore, it is crucial to ensure the stability of the sensor field of view during flight.

[0003] In order to ensure the quality of the field of view stabilization, the commonly used technical solution is a stabilized gimbal. The stabilized gimbal senses the attitude jitter of the unmanned aerial vehicle through internal inertial measurement elements, and drives the motor to generate a reverse motion to isolate the disturbance, thereby providing a stable observation platform for the hyperspectral sensor. This solution can effectively suppress low-frequency oscillation and improve imaging quality. However, the stabilized gimbal itself has obvious defects: in order to achieve sufficient stabilization torque, the gimbal structure is often heavy and bulky, resulting in high system cost and increasing the load of the unmanned aerial vehicle platform, which shortens the endurance time. The more prominent problem is its poor universality. Since different models of hyperspectral sensors differ significantly in weight, size and interface, it is usually necessary to customize the gimbal for specific loads and models, and one gimbal is difficult to adapt to multiple task requirements, which seriously restricts the flexibility and large-scale application of the equipment, and is a problem to be solved for current hyperspectral unmanned aerial vehicle systems. SUMMARY

[0004] Based on the above-mentioned shortcomings of the prior art, the purpose of the present application is to provide a hyperspectral camera system with self-stabilized and self-adjusted field of view and a control method to solve the above technical problems.

[0005] To achieve the above-mentioned purpose, the present application provides the following technical solution: a hyperspectral camera system with self-stabilized and self-adjusted field of view, comprising: a first imaging lens group, a movable slit, a two-dimensional linear actuator, a slit outer light shield, a collimating lens group, a light splitting element, a second imaging lens group, a planar image sensor, an attitude sensor and a control acquisition circuit; The first imaging lens group is used to focus the incident light to the movable slit. The movable slit is fixedly connected with a two-dimensional linear driver, and the two-dimensional linear driver is used for driving the slit to precisely displace in a plane thereof in two mutually orthogonal directions; the movable slit and the two-dimensional linear driver are arranged in a closed shell of a slit outer light shield; A collimating mirror group is arranged behind the slit and is used for collimating the light beam passing through the slit and then sending the light beam into a light splitting element; the light splitting element is used for dispersing the light beam according to wavelengths; and a second imaging mirror group is used for converging and imaging the dispersed light beam on an image sensor, so that a first direction of the image sensor represents spatial information and a second direction represents spectral information; An attitude sensor is mounted on the camera body and is used for outputting angle jitter data of the camera around a pitch direction and a roll direction in real time; A control acquisition circuit is electrically connected with the image sensor, the attitude sensor and the two-dimensional linear driver, and is configured to: based on the angle jitter data and pre-stored optical and geometric calibration parameters, calculate a two-dimensional compensation displacement of the slit required for offsetting external jitter in real time, drive the two-dimensional linear driver to move the slit in a reverse direction, so that a light spot position on the image sensor remains unchanged during acquisition; and control the slit to move at a constant speed along a direction to complete spatial scanning during push-broom imaging.

[0006] The application is further provided with two two-dimensional linear voice coil actuators arranged in mutually orthogonal directions.

[0007] The application is further provided with a light splitting element which is a plane reflective grating, a convex reflective grating, a prism, a plane transmission grating or a grating prism group.

[0008] The application is further provided with an image sensor which is a CMOS, a CCD or an InGaAs array sensor.

[0009] The application is further provided with a self-checking and initialization performed by the control acquisition circuit after the system is powered on, the movable slit is moved to a preset initial position, and optical and geometric calibration parameters are loaded.

[0010] The application is further provided with the control acquisition circuit which periodically triggers the image sensor to expose and acquire data at a fixed frame rate, and the circuit synchronously records accurate slit position coordinates corresponding to each frame of hyperspectral image data and instantaneous attitude data provided by the attitude sensor.

[0011] The application further provides a control method of a field self-stabilizing and self-adjusting hyperspectral camera, applied to the field self-stabilizing and self-adjusting hyperspectral camera system. Real-time device angle disturbance data output by the attitude sensor is acquired, and a current position of a slit center fed back by the two-dimensional linear driver is synchronously read; Based on the pre-calibrated imaging lens focal length and geometric mapping, the angle disturbance is converted into image offset, combined with the center field reference position obtained by system initialization, to obtain the slit center target position; According to the difference between the current position and the target position of the slit center, two-dimensional driving amount is calculated, and driving instructions are issued to the two-dimensional linear driver, so that the slit generates reverse displacement in its plane, and through the optical conjugate relationship, the external disturbance is offset, and the field is self-stabilized. When collecting frame by frame or line by line, the accurate position and attitude data of the slit at the corresponding moment are recorded synchronously; For the field tilt aberration and spectral curvature aberration varying with the slit position, the multidimensional mapping between the slit position and the original coordinates and ideal coordinates obtained by pre-calibration is called, interpolation or segmented selection is performed according to the current slit position, geometric transformation and resampling are completed in programmable logic or processor, and corrected hyperspectral image data is generated, so that the field is self-adjusted.

[0012] The application is further provided, the multidimensional mapping is established by a monochromatic light source and a precision displacement platform in the slit moving range and the detector imaging range to form a discrete measurement grid, a forward mapping and a lookup table, the lookup table is parameterized and compressed, and the mapping coefficient is obtained by interpolation or segmented model with the change of the slit position.

[0013] The application is further provided, after the acquisition is completed, the dark background data collected in advance is called to perform dark background deduction on the original data, so as to eliminate the dark current and readout noise. According to the preset field tilt aberration and spectral curvature aberration correction process, the hyperspectral data cube is output.

[0014] The application provides a hyperspectral camera system and control method with self-stabilization and self-adjustment of field of view, which comprises a first imaging lens group, a movable slit, a two-dimensional linear driver, a slit outer light shield, a collimating lens group, a light splitting element, a second imaging lens group, a planar image sensor, an attitude sensor and a control acquisition circuit; the first imaging lens group is used for focusing incident light to the movable slit; the movable slit is fixedly connected with the two-dimensional linear driver, and the two-dimensional linear driver is used for driving the slit to precisely displace in a plane thereof in two mutually orthogonal directions; the movable slit and the two-dimensional linear driver are arranged in a closed shell of the slit outer light shield; the collimating lens group is arranged behind the slit and sends the light beam passing through the slit to the light splitting element after collimation, the light splitting element is used for dispersing the light beam according to wavelength, and the second imaging lens group is used for converging and imaging the dispersed light on the image sensor, so that a first direction of the image sensor represents spatial information and a second direction represents spectral information; the attitude sensor is installed on a camera body and is used for outputting angle jitter data of the camera around pitch and roll directions in real time; the control acquisition circuit is electrically connected with the image sensor, the attitude sensor and the two-dimensional linear driver and is configured to: based on the angle jitter data and pre-stored optical and geometric calibration parameters, calculate a two-dimensional compensation displacement of the slit required for offsetting external jitter in real time and drive the two-dimensional linear driver to drive the slit to reversely displace, so that a light spot position on the image sensor remains unchanged during acquisition; wherein the control acquisition circuit is further configured to control the slit to move at a constant speed along a direction to complete spatial scanning when push-broom imaging is performed, and the beneficial effects include: The present hyperspectral imaging system adopts a movable slit structure to realize self-stabilization of the field of view, which is particularly advantageous in the unmanned aerial vehicle scene. By controlling the precise displacement of the slit to compensate for changes in flight attitude, the traditional mechanical gimbal can be effectively replaced; both the stability of the field of view is ensured, and the volume, weight and manufacturing cost are greatly reduced, which is more suitable for the stringent requirements of small and lightweight loads on unmanned aerial vehicle platforms; Compared with the scheme of the traditional unmanned aerial vehicle-mounted hyperspectral system which needs to be matched with an external gimbal, the present system realizes stability by relying on internal active control of the slit, which not only significantly simplifies the structure, but also improves the environmental adaptability. The same hardware platform can consider both anti-shake image stabilization and regional scanning imaging functions through intelligent switching control mode, thereby enhancing the multifunctionality and reliability in complex flight tasks; For the Keystone and Smile distortion of the system caused by the movement of the slit, a dynamic real-time correction scheme is adopted to achieve accurate compensation. By pre-calibration to establish the corresponding relationship between the slit position and the distortion variable, and then using a mathematical model to compress a large amount of correction data into a small number of core parameters, the current slit position is obtained synchronously during work, the parameters are called to quickly calculate the distortion compensation amount, and the interpolation algorithm is used to complete real-time correction, finally outputting a hyperspectral image without spatial registration deviation (Keystone) and spectral curvature (Smile), thereby ensuring the quantitative analysis accuracy of the data.

[0015] The above description is only a summary of the technical solutions of the present application. In order to more clearly understand the technical means of the present application, the specific embodiments of the present application can be implemented according to the content of the description, and in order to make the above and other purposes, characteristics and advantages of the present application more obvious and easy to understand, the following specific embodiments of the present application are described. BRIEF DESCRIPTION OF DRAWINGS

[0016] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following will briefly introduce the drawings needed in the embodiment description. Obviously, the drawings in the following description are only some embodiments of the present application, and those skilled in the art can obtain other drawings according to these drawings without any creative labor. In the drawings: Figure 1 A structure diagram of a field-of-view self-stabilizing and self-adjusting hyperspectral camera system is shown for an exemplary embodiment of the present application; Figure 2 An imaging diagram of a movable slit is shown for an exemplary embodiment of the present application; Figure 3 A structure diagram of a movable slit and a light shield cover outside the slit is shown for an exemplary embodiment of the present application. DETAILED DESCRIPTION

[0017] The embodiments of the present application will be described below with reference to the drawings and preferred embodiments, and those skilled in the art can easily understand other advantages and effects of the present application from the content disclosed in the specification. The present application can also be implemented or applied by different specific embodiments, and the details in the specification can be modified or changed based on different views and applications without departing from the spirit of the present application. It should be understood that the preferred embodiments are only for illustrating the present application, but not for limiting the protection scope of the present application.

[0018] It should be noted that the diagrams provided in the following embodiments only illustrate the basic concept of the present application in a schematic manner, and only the components related to the present application are shown in the diagrams, but not the number, shape and size of the components when actually implemented. The actual implementation of each component may be a random change, and the component layout pattern may be more complex.

[0019] In the following description, a large number of details are discussed to provide a more thorough explanation of the embodiments of the present application, however, it is obvious to those skilled in the art that the embodiments of the present application can be implemented without these specific details, and in other embodiments, the known structures and devices are shown in the form of block diagrams rather than in the form of details, to avoid making the embodiments of the present application difficult to understand.

[0020] Embodiment one: a field-of-view self-stabilizing and self-adjusting hyperspectral camera system, as shown in Figure 1 comprises: a first imaging lens group, a movable slit, a two-dimensional linear driver, a slit outer light shield, a collimating lens group, a light splitting element, a second imaging lens group, a planar image sensor, an attitude sensor, and a control acquisition circuit; The first imaging lens group is used to focus the incident light to the movable slit. The movable slit is fixedly connected with the two-dimensional linear driver, and the two-dimensional linear driver is used to drive the slit to precisely displace in its plane in two mutually orthogonal directions; the movable slit and the two-dimensional linear driver are arranged in the closed shell of the slit outer light shield. The collimating lens group is arranged behind the slit and collimates the light beam passing through the slit and then sends it into the light splitting element; the light splitting element is used to disperse the light beam according to wavelength; and the second imaging lens group is used to converge and image the dispersed light on the image sensor, so that the first direction of the image sensor represents spatial information and the second direction represents spectral information. The attitude sensor is installed on the camera body and is used to output the angular jitter data of the camera around the pitch and roll directions in real time. The control acquisition circuit is electrically connected with the image sensor, the attitude sensor, and the two-dimensional linear driver, and is configured to: based on the angular jitter data and the pre-stored optical and geometric calibration parameters, calculate the two-dimensional compensation displacement of the slit required to offset the external jitter in real time and drive the two-dimensional linear driver to drive the slit to move reversely, so that the light spot position on the image sensor remains unchanged during the acquisition process; and the control acquisition circuit is further configured to control the slit to move at a constant speed along a direction to complete spatial scanning when push-broom imaging is performed.

[0021] Specifically, the first imaging lens group (corresponding to the imaging lens group L in the figure): located at the front end of the system, responsible for collecting the scene light signal of the target region to be measured, converging and imaging the spatial light field of the target object on the slit plane, and providing a clear incident light spot for subsequent light splitting and detection. The optical parameters (such as focal length, field of view angle) determine the basic field of view range and spatial resolution of the system.

[0022] The movable slit (corresponding to the slit in the figure): installed at the image plane position of the imaging lens group L, fixed on the two-dimensional linear driver through a mechanical structure. Its core function is to spatially limit the imaging light spot and only allow the light passing through the slit opening, thereby defining a narrow imaging area on the image sensor. The slit can be accurately moved in the XY plane under the driving of the two-dimensional linear driver, and the direction of the slit remains unchanged and no light leakage gap is generated around the slit during the movement. Figure 2 As shown in the figure, by moving the slit, the center of the imaging field of view can be adjusted and selected.

[0023] The two-dimensional linear actuator is the key actuator of this system. It consists of two linear voice coil actuators combined in mutually orthogonal directions. Preferably, a combination of two linear voice coil motors is used, providing linear driving force in mutually orthogonal directions (X-axis and Y-axis), together forming a compact two-dimensional motion platform. This design features high acceleration, fast response speed, high positioning accuracy, and ease of miniaturization, making it ideal for applications requiring rapid jitter compensation for field-of-view stabilization. The actuator is directly connected to the movable slit via a mechanical structure and controlled by a control acquisition circuit via a cable, receiving commands to drive the slit to perform precise displacement within the plane.

[0024] Slit outer light shield: such as Figure 3 As shown, it is a sealed shell structure that encapsulates the movable slit and the overall motion mechanism of the two-dimensional linear actuator, and is fixed to the main frame of the camera. Its main functions are twofold: first, physical protection to prevent dust and foreign objects from intruding and affecting the precise movement of the slit; second, isolation of stray light, strictly shielding light entering from directions outside the optical path design to avoid scattering noise, thereby significantly improving the system's signal-to-noise ratio and spectral measurement accuracy. Its internal design provides the necessary space for the two-dimensional movement of the slit while ensuring that no light leakage gaps occur at any movement position.

[0025] Collimating lens group (corresponding to collimating lens group L1 in the figure): Located behind the slit and the light shield, with its object-side focal point coinciding with the plane of the slit. Its function is to collimate the diverging beam passing through the slit into approximately parallel light before it is incident on the beam splitter, ensuring that the beam splitter can achieve beam dispersion under optimal operating conditions.

[0026] Beam splitter: Located in the parallel light path after the collimating lens group L1, it uses the principle of dispersion (such as grating diffraction or prism refraction) to decompose the incident composite parallel light into monochromatic light with different propagation directions according to wavelength. The beam splitter can be a plane reflection grating, a convex reflection grating, a prism, a plane transmission grating, or a grating prism group, etc.

[0027] The second imaging lens group (corresponding to imaging lens group L2 in the diagram): located after the beam splitter, it is responsible for converging the monochromatic light of different wavelengths after dispersion and imaging it again onto the target surface of the image sensor. Its optical path design allows one dimension of the image sensor to correspond to spatial information (determined by the slit length direction), and the other dimension to correspond to spectral information.

[0028] The area array image sensor (corresponding to the image sensor in the diagram) is located at the image plane of imaging lens group L2 and is connected to the control and acquisition circuit via a cable. Its function is to convert the received light signal into an electrical signal. The image sensor can be a CMOS, CCD, or InGaAs array sensor, etc. The sensor target surface size needs to be large enough to ensure that its conjugate image always falls completely within the effective area of ​​the sensor when the slit moves.

[0029] Control and acquisition circuit: As the central hub of the system, it integrates the processing unit. It connects to and controls the two-dimensional linear actuator (driving the slit movement), image sensor (triggering acquisition and data reading), and attitude sensor via cables. Its main functions include: generating image trigger signals, acquiring image data, receiving camera angle jitter data measured by the attitude sensor, running a field-of-view stabilization control algorithm to calculate the real-time two-dimensional compensation displacement required for the slit, driving the two-dimensional linear actuator (such as two linear voice coil motors) for rapid and precise compensation movement, and controlling the slit to move at a constant speed along a one-dimensional direction in pushbroom mode to achieve spatial scanning.

[0030] Attitude sensor: Mounted on the camera body and connected to the control and acquisition circuitry via cable. It detects the angular jitter (in radians) of the camera system around the X and Y axes in real time and provides this attitude change data to the control and acquisition circuitry. This sensor is crucial for achieving field-of-view self-stabilization, providing the necessary input to the control algorithm to calculate the two-dimensional slit compensation displacement required to counteract external jitter.

[0031] (1) System Initialization and Self-Test: After the system is powered on, the control acquisition circuit starts the self-test process to confirm that the image sensor, 2D linear actuator, attitude sensor and other components are in normal condition. The 2D linear actuator moves the movable slit to the preset initial position (such as the mechanical zero point). The attitude sensor starts to warm up and the output data tends to stabilize. The system loads pre-calibrated optical parameters (such as the conversion relationship between focal length, slit displacement and object-side field of view movement) to prepare for field of view stabilization calculation.

[0032] (2) Real-time field-of-view self-stabilizing closed-loop control: This is the core process, operating continuously at high speed during UAV flight and data acquisition. The attitude sensor monitors the angular jitter data of the UAV around the X and Y axes in real time at high frequency and transmits it to the control acquisition circuit. Based on the received real-time jitter data and pre-loaded optical parameters, the control acquisition circuit quickly calculates the compensation displacement (direction and distance) of the movable slit required to counteract this jitter. The calculated compensation command is sent to the two-dimensional linear actuator in real time. The actuator immediately drives the movable slit to perform a precise reverse displacement, directly stabilizing the field of view on the optical image plane through the optical conjugate relationship, ensuring that the position of the light spot on the image sensor is fixed.

[0033] (3) Synchronous Data Acquisition: Under the premise that the UAV provides push-broom motion during flight, the core operation of the system is to maintain a stable field of view and acquire data synchronously. The real-time field of view self-stabilization closed-loop control in step (2) above continues to operate. The control acquisition circuit periodically triggers the image sensor to perform exposure and data acquisition at a fixed frame rate. While acquiring each frame of hyperspectral image data, the circuit simultaneously records the precise slit position coordinates corresponding to that frame of data and the instantaneous attitude data provided by the attitude sensor. These data provide key spatial position and attitude references for subsequent construction of the hyperspectral data cube, etc.

[0034] (4) Data Preprocessing and Output: After acquisition, the raw data can be preprocessed. First, the pre-acquired and stored dark background data is retrieved to subtract the dark current and readout noise of the image. Then, distortion is compensated according to the preset Keystone and SMILE aberration real-time correction algorithms. Finally, a hyperspectral data cube with accurate spatial coordinates and reliable spectral information is output.

[0035] Example 2: This exemplary method for controlling a hyperspectral camera with self-stabilized and self-adjusting field of view is applied to the aforementioned hyperspectral camera system with self-stabilized and self-adjusting field of view, and includes: The device angle disturbance data output by the attitude sensor is acquired in real time, and the current position of the slit center fed back by the two-dimensional linear actuator is read synchronously. Based on the pre-calibrated focal length and geometric mapping of the imaging lens group, the angular disturbance is converted into an image-side offset, which is then combined with the central field-of-view reference position obtained during system initialization to obtain the target position at the center of the slit. The two-dimensional driving amount is calculated based on the difference between the current position of the slit center and the target position. A driving command is sent to the two-dimensional linear actuator to make the slit produce a reverse displacement in its plane. External disturbances are canceled through optical conjugate relationship to achieve field self-stabilization. During frame-by-frame or line-by-line acquisition, the precise position and attitude data of the slit at the corresponding moment are recorded synchronously. To address the field tilt aberration and spectral curvature aberration that vary with the slit position, the system calls upon the pre-calibrated multidimensional mapping between the slit position and the original coordinates and the ideal coordinates. Interpolation or segmentation is performed according to the current slit position, and geometric transformation and resampling are completed in the programmable logic or processor to generate corrected hyperspectral image data, thereby achieving self-adjustment of the field of view.

[0036] Specifically, data is acquired from attitude sensors and two-dimensional linear actuators: attitude sensors (such as gyroscopes) monitor the angular jitter data of the device around the X and Y axes in real time at high frequency. Synchronously read the current actual position of the slit center fed back by the two-dimensional linear actuator. The two types of data are then transmitted to the control circuit as the basis for calculation.

[0037] Calculate the image-side offset and slit target position: The control circuit calls the pre-calibrated physical focal length f of the imaging lens group to calculate the image-side offset. ;in, and These are the image-side offsets in the x and y directions, respectively, and f is the focal length. For trigonometric functions, and These are the camera jitter angles around the X and Y axes, respectively, provided by the attitude sensor.

[0038] Then, through the reference position of the slit center corresponding to the central field of view. (Determined during system initialization) The target position of the slit center is obtained by combining the calculated image-side offset: ; ;in, and The target location is the center of the slit.

[0039] Calculate the actuator's driving force and drive the slit displacement: via the slit center's current actual position. and the target position of the slit center Calculate the driver's drive quantity: ;in, , To calculate the driving amount (including direction and distance) of the slit from its current position to the target position, the driving command is then sent to a two-dimensional linear actuator. The actuator immediately drives the slit to complete the corresponding displacement, using optical conjugate relationships to counteract equipment jitter and ensure a stable field of view.

[0040] Keystone and SMILE aberration real-time correction algorithms: When the slit is fixed, Keystone and Smile are static aberrations, which can be compensated for using only a set of fixed calibration parameters (such as a lookup table, LUT). However, when the slit moves in the XY plane, changes in the field of view (light rays incident at different angles to the subsequent collimating lens group L1 and beam splitter, altering the optical path) and the non-ideal nature of the optical system (differences between edge and center aberrations of the lens group) cause Keystone and Smile distortions to become part of the slit position (x-axis). s ,y s Therefore, a dynamic calibration method is required because it is a function of ).

[0041] Keystone and SMILE aberration correction table pre-calibration: In the laboratory, using an actual imaging model measured with a monochromator and a precision displacement platform, a mapping function of "slit position - original coordinates - ideal coordinates" is established.

[0042] Establish discrete position points within the slit's movement range: Establish discrete coordinate points within the detector's range: .

[0043] Establish a forward mapping: for each quadruple array That is, using a monochromatic point light source to illuminate the detector, so that the detector... Pixel response. And record the corresponding ideal image coordinates at this time. Then the forward mapping is ; Construct Keystone and SMILE aberration correction tables: for each required output The goal is to find the input (u,v) that makes the measured value closest to (u',v'), i.e. The results are then stored in the Keystone and Smile aberration correction tables: .

[0044] Keystone and SMILE aberration correction table parameterization: The original Keystone correction map is defined as follows: ; Using relative offset as a description: ;

[0045] Parametric compression model: ; ; coefficient and It is the slit position The function can be further parameterized as follows: ; ; Keystone and SMILE aberration real-time correction: While acquiring each frame (or each line) of image, a high-precision slit position sensor is simultaneously read to obtain the precise coordinates of the slit at that moment. .according to Retrieve the corresponding Keystone and Smile correction maps from the pre-calibrated multidimensional lookup table. In the FPGA or processor, the invoked correction map is used to correct the original image. Perform real-time geometric transformations and resampling (such as bilinear or cubic convolution interpolation) to generate the corrected image. The corrected hyperspectral image data, free from Keystone and Smile distortions, is output to the subsequent processing or storage unit.

[0046] In practical applications, the field-of-view self-stabilizing and self-adjusting hyperspectral camera control method provided in the above embodiments can be assigned to different functional modules as needed, that is, the internal structure of the system can be divided into different functional modules to complete all or part of the functions described above, and this is not a limitation.

[0047] The above description is merely a specific embodiment 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 hyperspectral camera system with self-stabilized and self-adjusting field of view, characterized in that, include: The system comprises a first imaging lens group, a movable slit, a two-dimensional linear actuator, an outer light shield for the slit, a collimating lens group, a beam splitter, a second imaging lens group, an area array image sensor, an attitude sensor, and a control and acquisition circuit. The first imaging lens group is used to focus the incident light onto the movable slit; The movable slit is fixedly connected to a two-dimensional linear actuator, which is used to drive the slit to make precise displacement in its plane in two mutually orthogonal directions; the movable slit and the two-dimensional linear actuator are housed in a sealed shell of the outer light shield of the slit. The collimating lens group is positioned after the slit and collimates the light beam passing through the slit before sending it into the beam splitter. The beam splitter is used to disperse the light beam according to wavelength. The second imaging lens group is used to converge the dispersed light and image it onto the image sensor, so that the first direction of the image sensor represents spatial information and the second direction represents spectral information. An attitude sensor is mounted on the camera body to output real-time angular jitter data of the camera around the pitch and roll directions; The control acquisition circuit is electrically connected to the image sensor, attitude sensor, and two-dimensional linear actuator. It is configured to: calculate in real time the two-dimensional compensation displacement of the slit required to offset external jitter based on angular jitter data and pre-stored optical and geometric calibration parameters, and drive the two-dimensional linear actuator to move the slit in the opposite direction so that the position of the light spot on the image sensor remains unchanged during the acquisition process; the control acquisition circuit is also configured to control the slit to move at a constant speed in one direction to complete the spatial scan during push-broom imaging.

2. The hyperspectral camera system with self-stabilized and self-adjusting field of view according to claim 1, characterized in that, A two-dimensional linear actuator consists of two linear voice coil actuators combined in mutually orthogonal directions.

3. The hyperspectral camera system with self-stabilized and self-adjusting field of view according to claim 1, characterized in that, The beam splitting element is a planar reflective grating, a convex reflective grating, a prism, a planar transmission grating, or a grating prism assembly.

4. A hyperspectral camera system with self-stabilized and self-adjusting field of view according to claim 1, characterized in that, The image sensor is a CMOS, CCD, or InGaAs array sensor.

5. A hyperspectral camera system with self-stabilized and self-adjusting field of view according to claim 1, characterized in that, After the system is powered on, the control and acquisition circuit performs self-test and initialization, moves the movable slit to the preset initial position and loads optical and geometric calibration parameters.

6. A hyperspectral camera system with self-stabilized and self-adjusting field of view according to claim 1, characterized in that, The control acquisition circuit periodically triggers the image sensor to perform exposure and data acquisition at a fixed frame rate. While acquiring each frame of hyperspectral image data, the circuit simultaneously records the precise slit position coordinates corresponding to that frame of data and the instantaneous attitude data provided by the attitude sensor.

7. A field-of-view self-stabilizing and self-adjusting hyperspectral camera control method, applied to a field-of-view self-stabilizing and self-adjusting hyperspectral camera system as described in any one of claims 1-6, characterized in that, include: The device angle disturbance data output by the attitude sensor is acquired in real time, and the current position of the slit center fed back by the two-dimensional linear actuator is read synchronously. Based on the pre-calibrated focal length and geometric mapping of the imaging lens group, the angular disturbance is converted into an image-side offset, which is then combined with the central field-of-view reference position obtained during system initialization to obtain the target position at the center of the slit. The two-dimensional driving amount is calculated based on the difference between the current position of the slit center and the target position. A driving command is sent to the two-dimensional linear actuator to make the slit produce a reverse displacement in its plane. External disturbances are canceled through optical conjugate relationship to achieve field self-stabilization. During frame-by-frame or line-by-line acquisition, the precise position and attitude data of the slit at the corresponding moment are recorded synchronously. To address the field tilt aberration and spectral curvature aberration that vary with the slit position, the system calls upon the pre-calibrated multidimensional mapping between the slit position and the original coordinates and the ideal coordinates. Interpolation or segmentation is performed according to the current slit position, and geometric transformation and resampling are completed in the programmable logic or processor to generate corrected hyperspectral image data, thereby achieving self-adjustment of the field of view.

8. The hyperspectral camera control method with self-stabilizing and self-adjusting field of view according to claim 7, characterized in that, Multidimensional mapping establishes a discrete measurement grid within the slit movement range and detector imaging range using a monochromatic light source and a precision displacement platform, forming a forward mapping and lookup table. The lookup table is then parameterized and compressed so that the mapping coefficients vary with the slit position and are obtained by interpolation or a piecewise model.

9. The hyperspectral camera control method with self-stabilizing and self-adjusting field of view according to claim 7, characterized in that, After the acquisition is completed, the pre-acquired dark background data is called to perform dark background subtraction on the original data to eliminate dark current and readout noise; The hyperspectral data cube is output according to the preset field tilt aberration and spectral curvature aberration correction process.

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