Adaptive calibration method and system for motion parameters of field-expanded remote sensing camera of optical fast reflector

Abstract

The invention relates to an adaptive calibration method and system for motion parameters of a field-of-view-expanded remote sensing camera of an optical fast reflecting mirror, and solves the problem that the positioning precision is reduced when the field of view of the remote sensing camera is expanded by the fast reflecting mirror. When a target is observed, accurate tracking of the target is achieved through the reflection and turning functions of the fast reflecting mirror, meanwhile, a calibration laser source is arranged to serve as a laser array and is used for emitting measurement laser, target light and the measurement laser are synchronously captured through the target and laser common-light-path detection imaging device, and the accurate result of laser detection is combined, so that the target is accurately detected. The actual rotation angle of the fast reflecting mirror can be calculated in real time, and high-precision positioning information of the field-of-view-expanded remote sensing camera of the optical fast reflecting mirror can be deduced according to the actual rotation angle. According to the method, the problems that the view field range of a traditional optical camera is limited, and large-angle scanning or tracking is difficult to achieve are solved, the bottleneck problems that the control precision of the fast reflecting mirror is insufficient, and the positioning precision is limited are solved, and the remote sensing camera gives consideration to view field expansion and high positioning precision.

Description

Technical Field

[0001] The present invention relates to the field of remote sensing technology, and particularly to an adaptive calibration method and system for the motion parameters of an optical fast steering mirror wide-field-of-view remote sensing camera. Background Art

[0002] As an important remote sensing technology tool, an optical camera (also known as a remote sensing camera) can quickly capture high-resolution images, showing significant advantages in the field of target detection and effectively meeting the diverse needs of various monitoring and analysis. Nevertheless, traditional optical cameras still face a major challenge in remote sensing applications, that is, their field of view is relatively limited, making it difficult to perform large-angle scanning or continuous tracking tasks, which has become the main bottleneck restricting the development of remote sensing technology. To break through this limitation, introducing fast steering mirror technology to expand the field of view has become a feasible solution. However, the current method of relying solely on an encoder to control the rotation angle and position of the fast steering mirror has significant defects, that is, it cannot ensure the accurate output of the motion angle of the fast steering mirror. This lack of accuracy directly weakens the positioning ability of the fast steering mirror, resulting in the difficulty of maintaining high-precision positioning while the remote sensing camera pursues an expanded field of view, thereby restricting the overall improvement of the intelligent level of the remote sensing camera. Summary of the Invention

[0003] Aiming at the problem of the decline in positioning accuracy accompanied by the expansion of the field of view of the fast steering mirror in a remote sensing camera, the present invention proposes an adaptive calibration method and system for the motion parameters of an optical fast steering mirror wide-field-of-view remote sensing camera.

[0004] To solve the above problems, the present invention adopts the following technical solutions:

[0005] An adaptive calibration method for the motion parameters of an optical fast steering mirror wide-field-of-view remote sensing camera, the method comprising the following steps:

[0006] Step 1: A remote sensing camera with a fast steering mirror detects the zero point of the parameter deviation identification and detection module, determines the zero point state, and calibrates the zero point of its own fast steering mirror motion parameters;

[0007] Step 2: The remote sensing camera obtains the expected motion curve of the fast steering mirror according to the input position and speed information of the detection target, and outputs the expected motion curve to the fast steering mirror controller;

[0008] Step 3: The fast steering mirror controller drives the fast steering mirror to perform corresponding rotational motion according to the expected motion curve;

[0009] Step 4: During the movement of the fast steering mirror, the remote sensing camera controls a plurality of calibration laser sources distributed in an array to continuously emit measurement lasers. All the measurement lasers are reflected by the fast steering mirror onto the focal plane of the detection and imaging device with the same optical path as the target and the laser. The detection and imaging device synchronously captures the target light and the measurement lasers, and while completing the imaging of the detection target, extracts the imaging position information of the measurement lasers at the calibration moment;

[0010] Step 5: Calculate the actual rotation angle of the fast steering mirror according to the imaging position information, determine the actual motion curve of the fast steering mirror according to the actual rotation angle, and feedback the actual motion curve to the remote sensing camera. The remote sensing camera obtains a high-precision positioning result according to the actual motion curve, and at the same time calculates the control error according to the actual motion curve and outputs it to the fast steering mirror controller. The fast steering mirror controller adjusts the rotation angle of the fast steering mirror according to the received control error, and then returns to Step 4.

[0011] Meanwhile, the present invention also proposes an adaptive calibration system for the motion parameters of an optical fast steering mirror and a wide-field-of-view remote sensing camera. The system includes a remote sensing camera with a fast steering mirror, calibration laser sources, a detection and imaging device with the same optical path as the target and the laser, and a parameter deviation identification and detection module, and a plurality of the calibration laser sources are distributed in an array;

[0012] The remote sensing camera is used to detect the zero point of the parameter deviation identification and detection module, determine the zero point state, perform zero point calibration on the motion parameters of its own fast steering mirror, obtain the expected motion curve of the fast steering mirror according to the input position and velocity information of the detection target, and output the expected motion curve to the fast steering mirror controller. The fast steering mirror controller drives the fast steering mirror to perform corresponding rotational motion according to the expected motion curve;

[0013] The calibration laser sources are used to continuously emit measurement lasers under the control of the remote sensing camera during the movement of the fast steering mirror. All the measurement lasers are reflected by the fast steering mirror onto the focal plane of the detection and imaging device;

[0014] The detection and imaging device is used to synchronously capture the target light and the measurement lasers, and while completing the imaging of the detection target, extract the imaging position information of the measurement lasers at the calibration moment;

[0015] The parameter deviation identification and detection module is used to calculate the actual rotation angle of the fast steering mirror according to the imaging position information, determine the actual motion curve of the fast steering mirror according to the actual rotation angle, and feedback the actual motion curve to the remote sensing camera. The remote sensing camera obtains a high-precision positioning result according to the actual motion curve. At the same time, the parameter deviation identification and detection module also calculates the control error according to the actual motion curve and outputs it to the fast steering mirror controller. The fast steering mirror controller adjusts the rotation angle of the fast steering mirror according to the received control error to achieve high-precision closed-loop control of the fast steering mirror.

[0016] Compared with the prior art, the present invention has the following beneficial effects:

[0017] The present invention provides an innovative method and system for adaptive calibration of motion parameters of an optical fast steering mirror wide-field remote sensing camera. When observing a target, the method and system utilize the reflection and folding functions of the fast steering mirror to achieve precise tracking of the target. At the same time, the system is equipped with a calibration laser source as a laser array for emitting measurement lasers, and a detection and imaging device with the same optical path for the target and the laser synchronously captures the target light and the measurement lasers. Combining the accurate results of laser detection, the actual rotation angle of the fast steering mirror can be calculated in real time, and based on this, the high-precision positioning information of the optical fast steering mirror wide-field remote sensing camera can be deduced. The present invention not only overcomes the problems of limited field of view of traditional optical cameras and difficulty in achieving large-angle scanning or tracking, but also solves the bottleneck problems of insufficient control accuracy and limited positioning accuracy of the fast steering mirror. The present invention enables the optical camera to maintain high-precision positioning ability while expanding the field of view, accurately output the motion angle of the fast steering mirror, provide instant feedback to the control system, and ensure that the system meets strict accuracy requirements. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 Shows a flowchart of the method for adaptive calibration of motion parameters of an optical fast steering mirror wide-field remote sensing camera according to an embodiment of the present invention.

[0019] Figure 2 Shows an imaging schematic diagram of the method for adaptive calibration of motion parameters of an optical fast steering mirror wide-field remote sensing camera according to an embodiment of the present invention.

[0020] Figure 3 Is a schematic diagram of the initial imaging position of the calibration laser source in an initial state in a specific embodiment of the present invention.

[0021] Figure 4 Is a schematic diagram of the change in the imaging position of the calibration laser source caused by interference during the working process of the remote sensing camera in a specific embodiment of the present invention.

[0022] Figure 5Schematic diagram of calibrating the imaging position of a laser source in a newly constructed coordinate system X′-Y′ in a specific embodiment of the present invention.

[0023] Figure 6 Schematic diagram of the change in calibrating the imaging position of a laser source when the fast steering mirror in a remote sensing camera rotates about the orthogonal axes in a specific embodiment of the present invention. Detailed implementation manners

[0024] The technical solution of the present invention will be described in detail below in conjunction with the accompanying drawings and embodiments.

[0025] In one embodiment, this embodiment proposes a method for adaptively calibrating the motion parameters of an optical fast steering mirror wide-field remote sensing camera. The method includes detecting an integrated remote sensing camera with imaging and laser emission and equipped with a fast steering mirror, and also includes a plurality of calibration laser sources and a detection imaging device 200 with the target and the laser sharing the same optical path, where the plurality of calibration laser sources are arranged in an array. The remote sensing camera is provided with a light shield, and the calibration laser source and the fast steering mirror are fixed on the light shield. The light shield is used to block unnecessary stray light and serve as the installation platform for the laser. The fast steering mirror is mainly used to expand the field of view of the remote sensing camera.

[0026] In the actual remote sensing imaging process, the remote sensing camera, according to the motion characteristics of the target, drives the fast steering mirror to rotate in two directions through the fast steering mirror controller, so as to achieve precise tracking of the target. At the same time, each calibration laser source continuously emits measurement laser to the fast steering mirror, and then all the measurement laser is reflected by the fast steering mirror to the focal plane of the detection imaging device. The fast steering mirror is not only responsible for reflecting and redirecting the light of the target, but also responsible for reflecting the measurement laser used to feedback the external parameter deviation information of the remote sensing camera. The detection imaging device captures these measurement lasers, and then calculates the actual rotation angle of the fast steering mirror, and feeds this information back to the remote sensing camera to calculate the control error. Subsequently, the fast steering mirror controller adjusts its output according to the received control error, so as to achieve high-precision closed-loop control of the fast steering mirror.

[0027] The integrated remote sensing camera with imaging and laser emission can collect the optical signals of the target scene to complete normal observation tasks, and also realizes the expansion of the field of view through the movement of the built-in fast steering mirror. At the same time, the calibration laser source equipped with this remote sensing camera can emit measurement laser, which can effectively measure the motion parameters of the fast steering mirror, effectively improving the positioning accuracy and making the remote sensing camera have higher measurement accuracy and adaptability in complex observation environments. More importantly, this measurement laser can feedback the external parameter deviation information of the remote sensing camera, which significantly improves the executability and accuracy of the remote sensing camera in the intelligent identification and detection of external parameter deviations.

[0028] See Figure 1 and Figure 2 , the present invention will be described in detail below with specific examples.

[0029] Step 1: Before the fast steering mirror of the remote sensing camera starts to move for field of view expansion, the remote sensing camera detects the zero point of the parameter deviation identification and detection module, determines the zero point state, and calibrates the zero point of the fast steering mirror movement parameters of itself. The zero point state includes the initial values of the parameters of the fast steering mirror and the calibration laser source, the initial value of the measurement laser imaging position, and the optical system transformation matrix of the remote sensing camera. Based on the high-precision spot positioning technology, the parameter deviation identification and detection module realizes the dynamic measurement and deviation output of the fast steering mirror movement parameters by capturing the centroid position of the spot on the image plane in real time.

[0030] In this embodiment, taking the number of calibration laser sources as 4 and installed on the light shield of the remote sensing camera as an example for illustration. The 4 calibration laser sources are respectively denoted as A, B, C, and D. In the ideal initial state, the angle θ0 between the fast steering mirror and the normal line is 45°, and the distance from the calibration laser source to the center point of the fast steering mirror is m. At this time, the measurement laser is reflected by the fast steering mirror and then imaged on the image plane of the detection imaging device with the same optical path as the laser to the target. As Figure 2 shown, the imaging points of the 4 calibration laser sources are respectively denoted as A″, B″, C″, D″, and A', B', C', D' are the intermediate images of the calibration laser sources A, B, C, D to the imaging points A″, B″, C″, D″ in sequence. The process of calibrating the zero point of the fast steering mirror movement parameters of the remote sensing camera by itself includes the following steps:

[0031] Step 1.1: Taking the parallel axis of the fast steering mirror as the X axis and the orthogonal axis as the Y axis to construct the image plane coordinate system X-Y, and determining the initial values of the imaging positions of each calibration laser source, that is, the initial values of the imaging point coordinates are (x i0 ,y i0 ), where i = A, B, C, D, and its initial imaging position is as Figure 3 shown. The coordinates of the imaging points of the calibration laser sources A, B, C, D are A0″=(x A0 ,y A0 ), B0″=(x B0 ,y B0 ), C0″=(x C0 ,y C0 ), D0″=(x D0 ,y D0 ). The distances from the imaging points A0″, B0″, C0″, D0″ to the center of the focal plane are the same, all being n, and the image points of the four calibration laser sources are distributed on the X axis and Y axis of the image plane coordinate system and symmetric about the origin.

[0032] Step 1.2: Considering the zero bias of the fast steering mirror, determine the initial values of the actual imaging point coordinates of each calibration laser source.

[0033] Due to many interference factors during the operation of the optical remote sensing camera, such as external space environmental disturbances like gravity and temperature, vibrations generated by the operation of satellite payloads such as satellite attitude control mechanisms, solar panels, and antennas, and the interference of various noises, these interference factors will cause the fast steering mirror to have a zero bias, which in turn causes the position of the actual initial image point of the calibration laser source to shift. Therefore, after considering the zero bias of the fast steering mirror, the actual initial imaging position of the calibration laser source is as Figure 4 shown. The initial values of the actual imaging point coordinates of calibration laser sources A, B, C, and D are A1″ = (x A1 , y A1 ), B1″ = (x B1 , y B1 ), C1″ = (x C1 , y C1 ), D1″ = (x D1 , y D1 ).

[0034] Step 1.3: Calculate the error movement distance of each calibration laser source according to the initial value of the actual imaging point coordinates determined in Step 1.2, and then calculate the corresponding error angle according to the error movement distance.

[0035] Taking the imaging point B” as an example, denote the angle between this B” and the orthogonal axis Y as Δθ B0 , and the formula for calculating the error movement distance d B1 from point B0″ to B1″ is:

[0036]

[0037] The formula for calculating the error angle of the imaging point B” is:

[0038]

[0039] where f is the focal length of the optical system of the remote sensing camera.

[0040] Similarly, the error angles of the imaging points A”, C”, and D” can be obtained as Δθ A0 , Δθ C0 , Δθ D0 .

[0041] Step 1.4: Calculate the average value of the error angles corresponding to each calibration laser source to obtain the zero bias angle of the fast steering mirror, and then obtain the angle between the fast steering mirror and the normal according to the zero bias angle.

[0042] The formula for calculating the zero bias angle Δθ0 of the fast steering mirror is:

[0043]

[0044] According to the zero bias angle, the angle between the fast steering mirror and the normal is:

[0045]

[0046] Among them, θ1 is the angle between the fast steering mirror and the normal line, and Δθ0 is the zero offset angle of the fast steering mirror.

[0047] Step 1.5: Rebuild a new coordinate system X′-Y′, and re-determine the imaging point coordinates of each calibration laser source in the new coordinate system X′-Y′.

[0048] In this step, a new coordinate system X′-Y′ is rebuilt. The origin of the new coordinate system X′-Y′ is the same as that of the original coordinate system X-Y. The Y′ axis is a straight line connecting the origin and the imaging point (imaging point B” in this embodiment) close to the Y axis in the original coordinate system X-Y. The straight line orthogonal to the Y′ axis is used as the X′ axis, thus constructing the new coordinate system X′-Y′. The positions of the imaging points of the calibration laser sources in the new coordinate system remain unchanged, but the corresponding coordinates of the imaging points change. As Figure 5 shown, in the new coordinate system X′-Y′, the imaging point coordinates of the calibration laser sources A, B, C, and D are A1″ = (x′ A1 , y′ A1 ), B1″ = (x′ B1 , y′ B1 ), C1″ = (x′ C1 , y′ C1 ), D1″ = (x′ D1 , y′ D1 ), respectively.

[0049] Step 2: According to the detection requirements of target tracking input, including the position and velocity information of the detection target, the remote sensing camera starts to operate. Based on the position and velocity information of the detection target, the remote sensing camera can obtain the expected motion curve f(t) of the fast steering mirror and output the expected motion curve f(t) to the fast steering mirror controller. Step 3: Subsequently, the fast steering mirror controller drives the fast steering mirror to perform corresponding rotational motion according to this expected motion curve f(t).

[0050] Step 4: During the rotational motion of the fast steering mirror, the remote sensing camera controls each calibration laser source to continuously emit measurement laser. All the measurement laser is reflected by the fast steering mirror onto the focal plane of the detection imaging device on the common optical path of the target and the laser. The detection imaging device simultaneously captures the target light and the measurement laser, and while completing the imaging of the detection target, accurately extracts the imaging position information of the measurement laser at the calibration moment.

[0051] Step 5: Calculate the actual rotation angle of the fast steering mirror according to the imaging position information, determine the actual motion curve of the fast steering mirror based on the actual rotation angle, and then feedback the actual motion curve to the remote sensing camera. The remote sensing camera obtains a high-precision positioning result according to the actual motion curve. At the same time, the parameter deviation identification and detection module calculates the control error according to the actual motion curve and outputs it to the fast steering mirror controller. The fast steering mirror controller adjusts the rotation angle of the fast steering mirror according to the received control error, and then returns to Step 4.

[0052] Taking the example that the fast steering mirror rotates by a certain angle around the parallel axis, the initial direction of the measurement laser emitted by the calibration laser source remains unchanged, but the angle of the light beam after being refracted and reflected by the fast steering mirror will change. This change directly causes the position of the imaging point of the laser beam on the focal plane of the detection imaging device to change. The specific position change is as Figure 6 shown. At this time, the positions of A2″ and C2″ remain unchanged compared with Figure 5 and are still on the new parallel axis X′. The positions of points B2″ and D2″ change, and their coordinates are B2″ = (x′ B2 , y′ B2 ), D2″ = (x′ D2 , y′ D2 ).

[0053] The process of calculating the actual rotation angle of the fast steering mirror according to the imaging position information specifically includes the following steps:

[0054] Step 5.1: After the fast steering mirror rotates, calculate the moving distance of the imaging point according to the imaging point coordinates of each calibration laser source in the new coordinate system X′-Y′, and then calculate the corresponding moving angle according to the moving distance;

[0055] Step 5.2: Calculate the average value of the moving angles of each imaging point to obtain the rotation angle of the fast steering mirror;

[0056] Step 5.3: Calculate the actual rotation angle of the fast steering mirror according to the absolute value of the difference between the zero-offset angle and the rotation angle of the fast steering mirror.

[0057] Taking the imaging point B” as an example, denote the angle between this B” and the orthogonal axis Y′ as Δθ B1 . After the fast steering mirror rotates, in the new coordinate system X′-Y′, the calculation formula for the moving distance d B2 of the imaging point B” is:

[0058]

[0059] The calculation formula for the moving angle Δθ B1 of the imaging point B” is:

[0060]

[0061] Among them, f is the focal length of the optical system of the remote sensing camera.

[0062] Similarly, the moving angles of the imaging points A'', C'', and D'' can be obtained as Δθ A1 , Δθ C1 , Δθ D1 .

[0063] Thus, the rotation angle Δθ1 of the fast steering mirror around the parallel axis is obtained as:

[0064]

[0065] Subsequently, by analyzing the imaging results, the actual pointing of the remote sensing camera and the pointing of the movement angle of the fast steering mirror can be obtained.

[0066] According to this embodiment, the actual rotation angle Δθ of the fast steering mirror is obtained, and the calculation formula of Δθ is:

[0067]

[0068] Among them, f is the focal length of the optical system of the remote sensing camera.

[0069] The rotation angle of the fast steering mirror is twice the deflection angle of the light, so the calculation formula of the deflection angle Δα of the light is:

[0070]

[0071] Based on the above information, combined with the position of the spot centroid, the actual motion curve f'(t) of the fast steering mirror of the remote sensing camera can be inversely deduced. At the same time, the actual motion curve f'(t) is instantaneously fed back to the remote sensing camera, ensuring that while the remote sensing camera meets the measurement accuracy requirements, it can also achieve high-level control and feedback, obtaining high-precision positioning results. At the same time, the parameter deviation identification and detection module calculates the control error of the fast steering mirror according to the actual motion curve f'(t), outputs the control error to the fast steering mirror controller, and the fast steering mirror controller adjusts the rotation angle of the fast steering mirror according to the received control error, and then returns to step 4 to achieve high-precision closed-loop control of the fast steering mirror.

[0072] Through the above embodiments, the actual rotation angle of the fast steering mirror and the actual motion curve for the detection target can be obtained, so as to obtain the high-precision positioning result of the adaptive calibration of the optical fast steering mirror wide-field remote sensing camera.

[0073] The proposed method for adaptively calibrating the motion parameters of an optical fast steering mirror with an extended field of view for a remote sensing camera can accurately track the target by utilizing the reflection and deflection functions of the fast steering mirror when observing the target. Meanwhile, a calibration laser source is equipped as a laser array to emit measurement lasers, and a detection imaging device with a common optical path for the target and the laser synchronously captures the target light and the measurement lasers. Combining the accurate results of laser detection, the actual rotation angle of the fast steering mirror can be calculated in real time, and based on this, the high-precision positioning information of the optical fast steering mirror with an extended field of view for the remote sensing camera can be deduced. This method not only overcomes the problems of the limited field of view of traditional optical cameras and the difficulty in achieving large-angle scanning or tracking, but also solves the bottleneck problems of insufficient control accuracy and limited positioning accuracy of the fast steering mirror, enabling the optical camera to maintain high-precision positioning capabilities while expanding the field of view, accurately output the motion angle of the fast steering mirror, provide immediate feedback to the control system, and ensure that the system meets strict accuracy requirements.

[0074] In another embodiment of the present invention, a system for adaptively calibrating the motion parameters of an optical fast steering mirror with an extended field of view for a remote sensing camera is proposed. The system includes a remote sensing camera with a fast steering mirror, a calibration laser source, a detection imaging device with a common optical path for the target and the laser, and a parameter deviation identification and detection module. The multiple calibration laser sources are distributed in an array. Among them, the remote sensing camera is mainly used for detecting and imaging the target scene, and the field of view is expanded by the fast steering mirror. The remote sensing camera mainly includes an imaging detector and an optical system. The imaging detector is responsible for capturing the optical signal of the target scene and converting it into an electrical signal, and the optical system is used to focus and guide the optical signal of the target scene to the imaging detector; the calibration laser source is mainly used for emitting measurement lasers; the fast steering mirror is mainly used for reflecting and deflecting the target light incident on the remote sensing camera and the measurement lasers emitted by the calibration laser source; the detection imaging device is mainly used for detecting the measurement lasers and the target light sent by the remote sensing camera; the parameter deviation identification and detection module is mainly used to obtain the adaptive conjugate detection result of the motion parameters of the optical fast steering mirror with an extended field of view for the remote sensing camera by combining the detection results of the detection imaging device and the rotation angle of the fast steering mirror.

[0075] Specifically, the remote sensing camera is used to detect the zero point of the parameter deviation identification and detection module to determine the zero point state, including the initial values of the parameters of the fast steering mirror and the calibration laser source, the initial value of the imaging position of the measurement laser, and the optical system transformation matrix, perform zero-point calibration of its own fast steering mirror motion parameters, and after the zero-point state identification and detection, obtain the expected motion curve of the fast steering mirror according to the input position and velocity information of the detected target, and output the expected motion curve to the fast steering mirror controller. The fast steering mirror controller drives the fast steering mirror to perform corresponding rotational motion according to the expected motion curve.

[0076] The calibration laser source is used to continuously emit measurement lasers under the control of the remote sensing camera during the motion of the fast steering mirror, and all the measurement lasers are reflected by the fast steering mirror onto the focal plane of the detection imaging device.

[0077] The detection and imaging device is used to synchronously capture the target light and the measurement laser, and while completing the imaging of the detection target, extract the imaging position information of the measurement laser at the calibration moment.

[0078] The parameter deviation identification and detection module is used to detect the attitude change of the remote sensing camera at the current moment relative to the zero state. Based on the high-precision spot positioning technology, it realizes the dynamic measurement and deviation output of the fast steering mirror motion parameters by capturing the centroid position of the spot on the image plane in real time. Specifically, the parameter deviation identification and detection module calculates the actual rotation angle of the fast steering mirror according to the imaging position information, determines the actual motion curve of the fast steering mirror according to the actual rotation angle, and feeds the actual motion curve back to the remote sensing camera. The remote sensing camera obtains a high-precision positioning result according to the actual motion curve. At the same time, the parameter deviation identification and detection module also calculates the control error according to the actual motion curve and outputs it to the fast steering mirror controller. The fast steering mirror controller adjusts the rotation angle of the fast steering mirror according to the received control error to achieve high-precision closed-loop control of the fast steering mirror.

[0079] Furthermore, the parameter deviation identification and detection module includes:

[0080] The moving angle calculation sub-module is used to calculate the moving distance of the imaging point according to the imaging point coordinates of each calibration laser source in the constructed new coordinate system X'-Y' after the fast steering mirror rotates, and then calculate the corresponding moving angle according to the moving distance;

[0081] The rotation angle calculation sub-module is used to calculate the average value of the moving angles of each imaging point to obtain the rotation angle of the fast steering mirror;

[0082] The actual rotation angle calculation sub-module is used to calculate the actual rotation angle of the fast steering mirror according to the absolute value of the difference between the zero bias angle and the rotation angle of the fast steering mirror.

[0083] For the implementation methods of the specific functions of each module in the optical fast steering mirror wide-field remote sensing camera motion parameter adaptive calibration system of the present invention, reference can be made to the implementation methods described in the embodiments of the optical fast steering mirror wide-field remote sensing camera motion parameter adaptive calibration method above, and details will not be described here.

[0084] The optical fast steering mirror wide-field remote sensing camera motion parameter adaptive calibration system proposed in this embodiment not only solves the problems in the related art that the field of view of the optical camera is relatively small and large-angle scanning or tracking cannot be performed, but also solves the problems of insufficient control accuracy and limited positioning accuracy of the fast steering mirror, enabling the remote sensing camera to take into account both a wide field of view and high positioning accuracy, and can accurately output the motion angle of the fast steering mirror to provide feedback for the control of the fast steering mirror to achieve the accuracy requirements.

[0085] However, the above embodiments are only examples for clear illustration and not limitations on the implementation manners. The method and system for adaptively calibrating the motion parameters of the optical fast steering mirror wide-field remote sensing camera according to the present invention are generally applicable to remote sensing satellite systems. For those of ordinary skill in the art, other different forms of changes or variations can be made based on the above description. It is not necessary and impossible to enumerate all the implementation manners here. And the obvious changes or variations derived therefrom are still within the protection scope of the present invention.

Claims

1. An adaptive calibration method for the motion parameters of an optical fast steering mirror wide-field remote sensing camera, characterized in that, It includes the following steps: Step 1: The remote sensing camera with a fast steering mirror detects the zero point of the parameter deviation identification and detection module, determines the zero point state, and calibrates the zero point of the motion parameters of its own fast steering mirror. Step 2: The remote sensing camera obtains the expected motion curve of the fast steering mirror according to the input position and velocity information of the detection target, and outputs the expected motion curve to the fast steering mirror controller. Step 3: The fast steering mirror controller drives the fast steering mirror to perform corresponding rotational motion according to the expected motion curve. Step 4: During the motion of the fast steering mirror, the remote sensing camera controls a plurality of calibrated laser sources distributed in an array to continuously emit measurement lasers. All the measurement lasers are reflected by the fast steering mirror onto the focal plane of the detection imaging device on the common optical path of the target and the laser. The detection imaging device synchronously captures the target light and the measurement laser, and extracts the imaging position information of the measurement laser at the calibration moment while completing the imaging of the detection target. Step 5: Calculate the actual rotation angle of the fast steering mirror according to the imaging position information, determine the actual motion curve of the fast steering mirror according to the actual rotation angle, and feedback the actual motion curve to the remote sensing camera. The remote sensing camera obtains a high-precision positioning result according to the actual motion curve, and at the same time calculates the control error according to the actual motion curve and outputs it to the fast steering mirror controller. The fast steering mirror controller adjusts the rotation angle of the fast steering mirror according to the received control error, and then returns to Step 4.

2. The method for adaptively calibrating the motion parameters of the optical fast steering mirror wide field remote sensing camera according to claim 1, wherein The process of the remote sensing camera calibrating the zero point of the motion parameters of its own fast steering mirror includes the following steps: Step 1.1: Taking the parallel axis of the fast steering mirror as the X axis and the orthogonal axis as the Y axis, construct an image plane coordinate system X-Y, and determine the initial values of the imaging point coordinates of each calibrated laser source. The distances from the imaging points of each calibrated laser source to the center of the focal plane are the same, and each imaging point is on the X axis and Y axis of the image plane coordinate system and is symmetrically distributed about the origin. Step 1.2: Considering the zero bias of the fast steering mirror, determine the initial values of the actual imaging point coordinates of each calibrated laser source. Step 1.3: Calculate the error movement distance of each calibrated laser source according to the initial values of the actual imaging point coordinates, and then calculate the corresponding error angle according to the error movement distance. Step 1.4: Calculate the average value of the error angles corresponding to each calibrated laser source to obtain the zero bias angle of the fast steering mirror, and obtain the angle between the fast steering mirror and the normal according to the zero bias angle. Step 1.5: Reconstruct a new coordinate system X'-Y'. The origin of the new coordinate system X'-Y' is the same as that of the original coordinate system X-Y. The Y' axis is a straight line connecting the origin and the imaging point close to the Y axis in the original coordinate system X-Y, and re-determine the imaging point coordinates of each calibrated laser source in the new coordinate system X'-Y'.

3. The method for adaptively calibrating the motion parameters of the optical fast steering mirror wide field-of-view remote sensing camera according to claim 2, wherein The angle between the fast steering mirror and the normal is: where θ1 is the angle between the fast steering mirror and the normal, and Δθ0 is the zero bias angle of the fast steering mirror.

4. The method for adaptively calibrating the motion parameters of the optical fast steering mirror wide-field remote sensing camera according to claim 2, wherein The process of calculating the actual rotation angle of the fast steering mirror according to the imaging position information includes the following steps: Step 5.1: After the fast steering mirror rotates, calculate the moving distance of the imaging points based on the imaging point coordinates of each calibration laser source in the new coordinate system X'-Y', and then calculate the corresponding moving angle according to the moving distance; Step 5.2: Calculate the mean value of the moving angles of each imaging point to obtain the rotation angle of the fast steering mirror; Step 5.3: Calculate the actual rotation angle of the fast steering mirror according to the absolute value of the difference between the zero-offset angle and the rotation angle of the fast steering mirror.

5. The method for adaptively calibrating the motion parameters of the optical fast steering mirror wide field remote sensing camera according to claim 1 or 2, characterized in that, The zero point state includes the initial values of the parameters of the fast steering mirror and the calibration laser source, the initial value of the measurement laser imaging position, and the optical system transformation matrix.

6. The adaptive calibration method for the motion parameters of the optical fast steering mirror wide-field remote sensing camera according to claim 1 or 2, characterized in that The number of the calibration laser sources is four.

7. The method for adaptively calibrating the motion parameters of the optical fast steering mirror wide-field remote sensing camera according to claim 1 or 2, characterized in that The remote sensing camera is provided with a light shield, and the calibration laser source is fixed on the light shield.

8. An adaptive calibration system for the motion parameters of an optical fast steering mirror wide-field remote sensing camera, characterized in that, The system includes a remote sensing camera with a fast steering mirror, calibration laser sources, a detection and imaging device with a common optical path for the target and the laser, and a parameter deviation identification and detection module, and multiple calibration laser sources are arranged in an array; The remote sensing camera is used to detect the zero point of the parameter deviation identification and detection module, determine the zero point state, perform zero point calibration on the motion parameters of its own fast steering mirror, and then obtain the expected motion curve of the fast steering mirror according to the input position and velocity information of the detection target, and output the expected motion curve to the fast steering mirror controller, and the fast steering mirror controller drives the fast steering mirror to perform corresponding rotational motion according to the expected motion curve; The calibration laser source is used to continuously emit measurement laser under the control of the remote sensing camera during the motion of the fast steering mirror, and all the measurement laser is reflected by the fast steering mirror to the focal plane of the detection and imaging device; The detection and imaging device is used to synchronously capture the target light and the measurement laser, and extract the imaging position information of the measurement laser at the calibration moment while completing the imaging of the detection target; The parameter deviation identification and detection module is used to calculate the actual rotation angle of the fast steering mirror according to the imaging position information, determine the actual motion curve of the fast steering mirror according to the actual rotation angle, and feedback the actual motion curve to the remote sensing camera. The remote sensing camera obtains a high-precision positioning result according to the actual motion curve. At the same time, the parameter deviation identification and detection module also calculates the control error according to the actual motion curve and outputs it to the fast steering mirror controller, and the fast steering mirror controller adjusts the rotation angle of the fast steering mirror according to the received control error to achieve high-precision closed-loop control of the fast steering mirror.

9. The optical fast steering mirror wide field of view remote sensing camera motion parameter adaptive calibration system according to claim 8, characterized in that, The parameter deviation identification and detection module includes: A moving angle calculation sub-module, which is used to calculate the moving distance of the imaging points based on the imaging point coordinates of each calibration laser source in the constructed new coordinate system X'-Y' after the fast steering mirror rotates, and then calculate the corresponding moving angle according to the moving distance; A rotation angle calculation sub-module, which is used to calculate the mean value of the moving angles of each imaging point to obtain the rotation angle of the fast steering mirror; An actual rotation angle calculation sub-module, which is used to calculate the actual rotation angle of the fast steering mirror according to the absolute value of the difference between the zero-offset angle and the rotation angle of the fast steering mirror.

10. The adaptive calibration system for the motion parameters of the optical fast steering mirror wide-field remote sensing camera according to claim 8 or 9, characterized in that, The zero-point state includes the initial values of the parameters of the fast steering mirror and the calibration laser source, the initial value of the measurement laser imaging position, and the optical system transformation matrix.

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