Automatic adjusting device and method for focal plane of laser detector for Fourier interference remote sensing instrument

Abstract

The invention provides a laser detector focal plane automatic adjusting device and method for a Fourier interference remote sensing instrument, and relates to the technical field of Fourier infrared remote sensing instruments. The device comprises a laser detector pre-amplification circuit, a laser detector high-speed AD sampling circuit, a laser detector six-axis displacement table, a laser detector six-axis displacement table driving module and a focal plane automatic adjustment master control module. The automatic assembling and adjusting device for the focal plane of the laser detector replaces the mode that gaskets are used for manually adjusting three translation shafts and three rotating shafts of a laser detector mounting structure in the prior art. A focal plane automatic adjustment device is used, a six-axis displacement table is controlled, laser interference signals are measured and collected in real time, the optimal focal plane position is automatically calculated through parameters such as frequency and amplitude of the laser interference signals, adjustment of the focal plane position of a laser detector is completed, and the adjustment efficiency and precision of a Fourier interference remote sensing instrument can be effectively improved.

Description

Technical Field

[0001] The present invention relates to the technical field of Fourier infrared remote sensing instruments, and in particular to a device and method for automatically adjusting the focal plane of a laser detector used in a Fourier interferometer remote sensing instrument. Background Art

[0002] Fourier transform infrared remote sensing instruments are extremely important in ground object research, Earth observation, gas monitoring, and environmental monitoring. Their multi-channel and high-throughput advantages enable them to acquire high-resolution spectral data with a high signal-to-noise ratio across a wide spectral range. A single observation can be used to invert multiple gas components, making them particularly suitable for atmospheric sounding. Consequently, they are a key infrared atmospheric sounding instrument being developed worldwide.

[0003] Fourier transform infrared remote sensing instruments, with their high efficiency, accuracy, and non-contact nature, are a core tool for hazardous gas detection in industrial safety, environmental monitoring, and emergency response. They offer spectral fingerprint recognition, passive remote sensing, non-contact capabilities, high sensitivity, and anti-interference capabilities.

[0004] With the development of spectral detection technology, its applications are becoming increasingly widespread. Fourier transform infrared remote sensing instruments are widely used in chemical park safety monitoring, emergency rescue and accident scene response, and industrial process safety control. They can comprehensively improve monitoring accuracy, range, early warning speed, and accuracy, and can address challenges in the construction and deployment of autonomous, controllable, and rapid early warning systems.

[0005] In Fourier infrared remote sensing instruments, the laser interferometer signal used as a sampling reference signal usually uses a helium-neon laser or a solid-state laser as the light source. The laser interferometer signal passing through the interferometer system is generally a single-frequency sinusoidal signal.

[0006] In the past research and development of Fourier infrared remote sensing instruments, when adjusting the laser interference signal, the mounting structure of the laser detector needs to be adjusted so that the light spot of the laser interference signal falls on the laser detector and a single-frequency sinusoidal signal is obtained after passing through the preamplifier circuit.

[0007] The debugging process generally involves using an oscilloscope to measure the signal output by the laser detector's preamplifier circuit, and using gaskets to adjust the three translation axes (X, Y, Z) and three rotation axes (θX, θY, θZ) of the laser detector's mounting structure. The adjustment process is complex and has high requirements for the assembly and adjustment process. Summary of the Invention

[0008] In view of this, in order to solve the above problems, the purpose of the present invention is to propose a device and method for automatic adjustment of the focal plane of a laser detector for Fourier interferometer remote sensing instruments. Through automated hardware and intelligent algorithms, the traditional manual adjustment method is completely revolutionized, and a six-axis translation stage is used to realize fully automatic scanning of the focal plane, thereby solving the limitations of traditional single-axis adjustment, improving signal accuracy, avoiding misjudgment of a single indicator based on the Q indicator, enhancing robustness, eliminating the need for complex optical models, simplifying the adjustment process, being compatible with detectors such as photodiodes or CCDs, reducing training costs, and effectively improving the adjustment efficiency and accuracy of Fourier interferometer instruments.

[0009] To achieve the above object, the present invention provides the following technical solutions: Based on the above objectives, in a first aspect, the present invention provides a laser detector focal plane automatic adjustment device for a Fourier interferometer remote sensing instrument, comprising a laser detector preamplifier circuit, a laser detector high-speed AD sampling circuit, a laser detector six-axis displacement stage, a laser detector six-axis displacement stage drive module, and a focal plane automatic adjustment main control module; the laser detector preamplifier circuit is connected to the laser detector, and the laser detector preamplifier circuit is also connected to the laser detector high-speed AD sampling circuit; the laser detector six-axis displacement stage carries a laser detector mounting structure, supporting degree of freedom adjustment on three translation axes and three rotation axes; the laser detector six-axis displacement stage is connected to the laser detector six-axis displacement stage drive module, and the laser detector high-speed AD sampling circuit and the laser detector six-axis displacement stage drive module are both connected to the focal plane automatic adjustment main control module; The laser detector preamplifier circuit is used to preamplify and filter the laser interference signal received by the laser detector; The laser detector high-speed AD sampling circuit is used to digitally collect the analog signal amplified by the connected laser detector preamplifier circuit; The six-axis laser detector translation stage carries the laser detector mounting structure and supports degree of freedom adjustment on three translation axes (X, Y, Z) and three rotation axes (θX, θY, θZ) to achieve focal plane adjustment of the laser detector. The laser detector six-axis translation stage driving module is used to drive the six-axis translation stage to move according to a preset step value; The focal plane automatic adjustment main control module is respectively connected to the laser detector high-speed AD sampling circuit and the laser detector six-axis translation stage drive module, and is used for automatic control of the six-axis translation stage, automatic collection of laser interference signals, automatic analysis of laser interference signals, and drawing of the response curve of the interference signal under the laser focal plane as a function of the focal plane position.

[0010] The laser detector focal plane automatic adjustment device of the present invention replaces the conventional method of using gaskets to adjust the three translation axes (X, Y, Z) and three rotation axes ( X、 Y. Z) manual adjustment. Using an automatic focal plane adjustment device to control a six-axis translation stage, real-time measurement and acquisition of laser interference signals, and automatically calculating the optimal focal plane position based on parameters such as the frequency and amplitude of the laser interference signal, the laser detector focal plane position is adjusted, effectively improving the adjustment efficiency and accuracy of Fourier interferometer remote sensing instruments.

[0011] As a further solution of the present invention, the laser detector is mounted on a six-axis translation platform, and the six-axis translation platform is used to control the laser detector mounting structure to move between three translation axes (X, Y, Z) and three rotation axes ( X、 Y. Z) to obtain the optimal focal position of the laser detector.

[0012] As a further solution of the present invention, the focal plane automatic adjustment main control module is used to analyze the frequency and amplitude of the laser interference signal collected by high-speed AD, determine the optimal position of the focal plane, and perform the following steps during automatic adjustment: Start the interferometer system and wait for the laser interferometer signal to stabilize; Start the automatic focal plane adjustment device and wait for the adjustment device to stabilize; The signal frequency of the laser interference signal is calculated based on the moving mirror and theoretical formula ; Control the six-axis translation stage to move along the translation axis X, according to the minimum step value that the translation stage can support , each time it moves to a certain position, a high-speed AD is used to collect data on the laser interference signal, and the data is recorded as D x1 to D xn , the translation axis X moves gradually from the translation axis Xmax to Xmin; Control the six-axis translation stage to move along the translation axis Y, according to the minimum step value that the translation stage can support , each time it moves to a certain position, a high-speed AD is used to collect data on the laser interference signal, and the data is recorded as D y1 to D yn , the translation axis Y is from the translation axis Y max Move gradually to Y min ; Control the six-axis translation stage to move along the translation axis Z according to the minimum step value that the translation stage can support , each time it moves to a certain position, a high-speed AD is used to collect data on the laser interference signal, and the data is recorded as D z1 to D zn , the translation axis Z is from the translation axis Z max Move gradually to Z min ; Control the six-axis translation stage along the rotation axis X rotation, according to the minimum step value that the stage can support X, each time it rotates to a certain position, a high-speed AD is used to collect data on the laser interference signal, and the data is recorded as D x1 to D xn , translation axis X from the translation axis X max Gradually move to X min ; Control the six-axis translation stage along the rotation axis Y rotation, according to the minimum step value that the translation stage can support Y, each time it rotates to a certain position, a high-speed AD is used to collect data on the laser interference signal, and the data is recorded as D y1 to D yn , translation axis Y from the translation axis Y max Gradually move to Y min ; Control the six-axis translation stage along the rotation axis Z rotation, according to the minimum step value that the translation stage can support Z, each time it rotates to a certain position, a high-speed AD is used to collect data on the laser interference signal, and the data is recorded as D z1 to D zn , translation axis Z from the translation axis Z max Gradually move to Z min ; For three translation axes (X, Y, Z) and three rotation axes ( X、 Y. Z) Laser interference signal data D recorded during displacement x1 to D xn 、D y1 to D yn 、D z1 to D zn 、D x1 to D xn 、D y1 to D yn 、D z1 to D zn Perform data feature extraction; According to the calculation formula of the built-in signal comprehensive quality index Q, the three translation axes (X, Y, Z) and the three rotation axes ( X、 Y. The peak amplitude A, frequency error Δf, and 3dB bandwidth B of the sensor are calculated respectively; Calculate the signal quality index Q independently for each axis and find the three translation axes (X, Y, Z) and three rotation axes ( X、 Y. The step position that makes Q maximum in Z) is recorded as X opt , Y opt , Z opt , X opt , Y opt , Z opt .

[0013] As a further solution of the present invention, the signal frequency of the laser interference signal The calculation formula is: Where, is the frequency of the interference signal in Hertz (Hz); is the moving mirror speed in meters per second (m / s); is the wavelength of the laser, in meters (m).

[0014] As a further solution of the present invention, when performing data feature extraction, three features are extracted from the signal data: peak amplitude A, frequency error Δf, and 3dB bandwidth B; wherein: Peak amplitude: A = signal strength index; Frequency error: Δf=|fpeak-f|, frequency center point stability index; 3dB bandwidth: B, frequency concentration index, that is, half-maximum width. The smaller the bandwidth, the purer the signal.

[0015] As a further solution of the present invention, when the peak amplitude A, the frequency error Δf, and the 3dB bandwidth B are calculated separately, the calculation formula of the comprehensive signal quality index Q is: .

[0016] As a further solution of the present invention, the laser detector preamplifier circuit is used to filter the input signal, and the laser detector preamplifier circuit includes: Photovoltaic amplifier circuit, receiving weak current signal from laser detector; MFB type high-pass filter circuit to filter out low-frequency noise; Fifth-order Butterworth low-pass filter circuit to suppress high-frequency interference.

[0017] As a further solution of the present invention, the laser detector high-speed AD sampling circuit is used to digitally process and collect analog signals from the laser detector preamplifier circuit and output digital signals.

[0018] As a further solution of the present invention, the laser detector six-axis translation stage adopts an H-bridge drive circuit, which realizes bidirectional control of the translation stage stepper motor through a power MOS tube, and is used to perform stepping drive operation on the laser detector six-axis translation stage used by the laser detector mounting structure.

[0019] As a further solution of the present invention, the focal plane automatic adjustment main control module uses an FPGA controller to automatically control the six-axis translation stage. The control process includes: Start the interferometry system and wait for the signal to stabilize; Move the stage along each axis sequentially to collect signal data step by step; Generate a response curve of signal quality index Q changing with position; Output the optimal focal plane coordinates.

[0020] In a second aspect, the present invention further provides a method for automatically adjusting the focal plane of a laser detector for a Fourier interferometer remote sensing instrument, comprising the following steps: Step 1: Start the interferometer system and wait for the laser interferometer signal to stabilize; Step 2: Calculate the theoretical interference frequency ,in is the moving mirror speed, λ is the laser wavelength; Step 3: Control the translation stage to move along the X / Y / Z / θX / θY / θZ axes in sequence, and collect signal data once for each movement step value Δ; Step 4: Extract the characteristic parameters A, Δf, and B of all data; Step 5: Press Calculate the Q value of each axis; Step 6: Positioning Q max The corresponding optimal focal position.

[0021] As a further solution of the present invention, signal feature extraction includes: Peak amplitude A: the maximum voltage value of the time domain signal; Frequency error Δf: actual spectrum peak frequency f peak Absolute deviation from the theoretical value f; 3dB bandwidth B: The frequency width when the spectrum peak power drops by 3dB.

[0022] As a further solution of the present invention, the step value (Δ) is the minimum displacement resolution supported by the translation stage, and the value range is 0.1 μm-10 μm (translation axis) or 0.001°-0.1° (rotation axis).

[0023] Compared with the prior art, the present invention proposes a device and method for automatically adjusting the focal plane of a laser detector for a Fourier interferometer remote sensing instrument, which has the following beneficial effects: The present invention achieves fully automated scanning of the detector focal plane by utilizing six-axis full-degree-of-freedom collaborative optimization, breaking through the limitations of traditional single-axis or three-axis adjustment. It can solve asymmetric problems such as focal plane tilt and offset in complex optical systems and significantly improve the accuracy of the laser signal of the interference system. The present invention also designs a set of intelligent signal quality evaluation system, by analyzing the laser interference signal in three translation axes (X, Y, Z) and three rotation axes ( X、 Y. The comprehensive quality indicator Q on the optical fiber Z) integrates the three key parameters of amplitude (A), frequency error (Δf), and spectral concentration (B): it avoids the risk of misjudgment caused by a single indicator (such as relying solely on amplitude), can quantitatively evaluate signal quality, and ensure the robustness of focal plane positioning. Without the need for optical system transfer functions or prior physical models, quantitative analysis can be achieved directly based on the spectral characteristics of the original interference signal, reducing dependence on system modeling accuracy and simplifying the calibration process. The system is compatible with various types of laser detectors (such as photodiodes, CCDs, etc.) and has strong versatility. The present invention adopts independent scanning of sub-axis and a local optimal combination strategy, which can achieve real-time adjustment and reduce the training costs of professional operators.

[0024] These and other aspects of the present application will be more clearly understood in the following description of the embodiments. It should be understood that the above general description and the following detailed description are merely exemplary and explanatory and cannot limit the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or related technologies, the following briefly introduces the drawings required for the exemplary embodiments or related technical descriptions. The drawings are used to provide a further understanding of the present invention and constitute part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention and do not constitute a limitation of the present invention. In the drawings: Figure 1This is a structural block diagram of an automatic adjustment device for the focal plane of a laser detector for a Fourier interferometer remote sensing instrument according to an embodiment of the present invention.

[0026] Figure 2 This is a schematic diagram of controlling the six-axis translation stage to move along the translation axis X in an automatic adjustment device for the focal plane of a laser detector for a Fourier interferometer remote sensing instrument according to an embodiment of the present invention.

[0027] Figure 3 This is a schematic diagram of controlling the six-axis translation stage to move along the translation axis Y in an automatic adjustment device for the focal plane of a laser detector for a Fourier interferometer remote sensing instrument according to an embodiment of the present invention.

[0028] Figure 4 This is a schematic diagram of controlling the movement of a six-axis translation stage along the translation axis Z in an automatic adjustment device for the focal plane of a laser detector for a Fourier interferometer remote sensing instrument according to an embodiment of the present invention.

[0029] Figure 5 The invention relates to a laser detector focal plane automatic adjustment device for a Fourier interferometer remote sensing instrument, which controls the six-axis translation stage to rotate along the axis. X rotation diagram.

[0030] Figure 6 The invention relates to a laser detector focal plane automatic adjustment device for a Fourier interferometer remote sensing instrument, which controls the six-axis translation stage to rotate along the axis. Schematic diagram of Y rotation.

[0031] Figure 7 The invention relates to a laser detector focal plane automatic adjustment device for a Fourier interferometer remote sensing instrument, which controls the six-axis translation stage to rotate along the axis. Schematic diagram of Z rotation.

[0032] Figure 8 This is a schematic diagram of laser interference signal data in an automatic focal plane adjustment device for a laser detector used in a Fourier interferometer remote sensing instrument according to an embodiment of the present invention.

[0033] Figure 9 Schematic diagram of calculation results of the comprehensive signal quality index Q in an automatic focal plane adjustment device for a laser detector used in a Fourier interferometer remote sensing instrument according to an embodiment of the present invention.

[0034] Figure 10 The present invention is a schematic diagram of a laser detector preamplifier circuit in an automatic adjustment device for the focal plane of a laser detector for a Fourier interferometer remote sensing instrument according to an embodiment of the present invention.

[0035] Figure 11 The figure is a schematic diagram of a high-speed AD sampling circuit of a laser detector in an automatic focal plane adjustment device for a Fourier interferometer remote sensing instrument according to an embodiment of the present invention.

[0036] Figure 12 The present invention is a schematic diagram of a driving circuit for a six-axis translation stage of a laser detector in an automatic adjustment device for the focal plane of a laser detector used in a Fourier interferometer remote sensing instrument according to an embodiment of the present invention.

[0037] Figure 13 The present invention provides an automatic adjustment flow chart of a method for automatically adjusting the focal plane of a laser detector for a Fourier interferometer remote sensing instrument according to an embodiment of the present invention. DETAILED DESCRIPTION

[0038] Below, the present application is further described in conjunction with the accompanying drawings and specific implementation methods. It should be noted that, under the premise of no conflict, the various embodiments or technical features described below can be arbitrarily combined to form new embodiments.

[0039] To make the purpose, technical solutions and advantages of the present invention more clearly understood, the following is a further detailed description of the embodiments of the present invention in conjunction with specific embodiments and with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are only used to explain the present application and are not intended to limit the present application.

[0040] It should be noted that all expressions using "first" and "second" in the embodiments of the present invention are intended to distinguish two non-identical entities or non-identical parameters with the same name. Therefore, "first" and "second" are used for convenience of expression only and should not be understood as limitations on the embodiments of the present invention. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions, for example, other steps or units inherent to a process, method, system, product, or device that includes a series of steps or units.

[0041] The following will be combined with the drawings in the embodiments of this application to clearly and completely describe the technical solutions in the embodiments of this application. Obviously, the embodiments described are part of the embodiments of this application, not all of them. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0042] The flowcharts shown in the accompanying drawings are for illustrative purposes only and do not necessarily include all contents and operations / steps, nor must they be executed in the order described. For example, some operations / steps may be decomposed, combined, or partially merged, so the actual execution order may vary depending on the actual situation.

[0043] The following describes some embodiments of the present application in detail with reference to the accompanying drawings. In the absence of conflict, the following embodiments and features therein may be combined with each other.

[0044] Due to the previous development process of Fourier infrared remote sensing instruments, the signal output by the preamplifier circuit of the laser detector is measured by an oscilloscope during debugging. The adjustment process is complicated and has high requirements for the installation and adjustment process. The present invention proposes an automatic adjustment device and method for the focal plane of a laser detector for Fourier interferometer remote sensing instruments. Through automated hardware and intelligent algorithms, it completely revolutionizes the traditional manual adjustment method. A six-axis translation stage is used to achieve fully automatic scanning of the focal plane, which solves the limitations of traditional single-axis adjustment, improves signal accuracy, avoids single-indicator misjudgment based on the Q index, enhances robustness, eliminates the need for complex optical models, simplifies the adjustment process, is compatible with detectors such as photodiodes or CCDs, reduces training costs, and can effectively improve the adjustment efficiency and accuracy of Fourier interferometer instruments.

[0045] See also Figure 1 As shown, an embodiment of the present invention provides a laser detector focal plane automatic adjustment device for a Fourier interferometer remote sensing instrument, including a laser detector preamplifier circuit, a laser detector high-speed AD sampling circuit, a laser detector six-axis displacement stage, a laser detector six-axis displacement stage drive module, and a focal plane automatic adjustment main control module; the laser detector preamplifier circuit is connected to the laser detector, and the laser detector preamplifier circuit is also connected to the laser detector high-speed AD sampling circuit; the laser detector six-axis displacement stage carries a laser detector mounting structure, supporting degree of freedom adjustment on three translation axes and three rotation axes; the laser detector six-axis displacement stage is connected to the laser detector six-axis displacement stage drive module, and the laser detector high-speed AD sampling circuit and the laser detector six-axis displacement stage drive module are both connected to the focal plane automatic adjustment main control module.

[0046] The laser detector preamplifier circuit is used to preamplify and filter the laser interference signal received by the laser detector; the laser detector high-speed AD sampling circuit is used to digitally collect the analog signal amplified by the connected laser detector preamplifier circuit; the laser detector six-axis displacement stage carries the laser detector mounting structure and supports degree of freedom adjustment on three translation axes (X, Y, Z) and three rotation axes (θX, θY, θZ) to achieve focal plane adjustment of the laser detector; the laser detector six-axis displacement stage drive module is used to drive the six-axis displacement stage to move according to a preset step value; the focal plane automatic adjustment main control module is respectively connected to the laser detector high-speed AD sampling circuit and the laser detector six-axis displacement stage drive module, and is used for automatic control of the six-axis displacement stage, automatic collection of laser interference signals, automatic analysis of laser interference signals, and drawing of a response curve of the interference signal under the laser focal plane with the focal plane position.

[0047] The laser detector focal plane automatic adjustment device of the present invention replaces the conventional method of using gaskets to adjust the three translation axes (X, Y, Z) and three rotation axes ( X、 Y. Z) manual adjustment. Using an automatic focal plane adjustment device to control a six-axis translation stage, real-time measurement and acquisition of laser interference signals, and automatically calculating the optimal focal plane position based on parameters such as the frequency and amplitude of the laser interference signal, the laser detector focal plane position is adjusted, effectively improving the adjustment efficiency and accuracy of Fourier interferometer remote sensing instruments.

[0048] In this embodiment, the laser detector is mounted on a six-axis translation platform, which controls the laser detector mounting structure to move between three translation axes (X, Y, Z) and three rotation axes ( X、 Y. Z) to obtain the optimal focal position of the laser detector.

[0049] The focal plane automatic adjustment main control module is used to analyze the frequency and amplitude of the laser interference signal collected by high-speed AD and determine the optimal position of the focal plane. Figures 1 to 9 As shown, the following steps are performed during automatic adjustment: Step 1: Start the interferometer system and wait for the laser interferometer signal to stabilize.

[0050] Step 2: Start the automatic focal plane adjustment device and wait for the adjustment device to stabilize.

[0051] Step 3: Calculate the signal frequency of the laser interference signal based on the moving mirror and theoretical formula ; Wherein, the signal frequency of the laser interference signal is The calculation formula is: Where, is the frequency of the interference signal in Hertz (Hz); is the moving mirror speed in meters per second (m / s); is the wavelength of the laser, in meters (m).

[0052] Step 4: Control the six-axis translation stage to move along the translation axis X, according to the minimum step value that the translation stage can support. , each time it moves to a certain position, a high-speed AD is used to collect data on the laser interference signal, and the data is recorded as D x1 to D xn , the translation axis X is from the translation axis X max Move gradually to X min , see Figure 2 shown.

[0053] Step 5: Control the six-axis translation stage to move along the translation axis Y, according to the minimum step value that the translation stage can support. , each time it moves to a certain position, a high-speed AD is used to collect data on the laser interference signal, and the data is recorded as D y1 to D yn , the translation axis Y is from the translation axis Y max Move gradually to Y min , see Figure 3 shown.

[0054] Step 6: Control the six-axis translation stage to move along the translation axis Z according to the minimum step value that the translation stage can support. , each time it moves to a certain position, a high-speed AD is used to collect data on the laser interference signal, and the data is recorded as D z1 to D zn , the translation axis Z is from the translation axis Z max Move gradually to Z min , see Figure 4 shown.

[0055] Step 7: Control the six-axis translation stage along the rotation axis X rotation, according to the minimum step value that the stage can support X, each time it rotates to a certain position, a high-speed AD is used to collect data on the laser interference signal, and the data is recorded as D x1 to D xn , translation axis X from the translation axis X max Gradually move to X min , see Figure 5 shown.

[0056] Step 8: Control the six-axis translation stage along the rotation axis Y rotation, according to the minimum step value that the translation stage can support Y, each time it rotates to a certain position, a high-speed AD is used to collect data on the laser interference signal, and the data is recorded as D y1 to D yn , translation axis Y from the translation axis Y max Gradually move to Y min , see Figure 6 shown.

[0057] Step 9: Control the six-axis translation stage along the rotation axis Z rotation, according to the minimum step value that the translation stage can support Z, each time it rotates to a certain position, a high-speed AD is used to collect data on the laser interference signal, and the data is recorded as D z1 to D zn , translation axis Z from the translation axis Z max Gradually move to Z min , see Figure 7 shown.

[0058] Step 10, the three translation axes (X, Y, Z) and the three rotation axes ( X、 Y. Z) Laser interference signal data D recorded during displacement x1 to D xn 、D y1 to D yn 、D z1 to D zn 、D x1 to D xn 、D y1 to D yn 、D z1 to D zn Extract data features. Taking the optimal position as an example, the laser interference signal data is as follows: Figure 8 shown.

[0059] When performing data feature extraction, three features are extracted from the signal data: peak amplitude A, frequency error Δf, and 3dB bandwidth B; among them: Peak amplitude: A = signal strength index; Frequency error: Δf=|fpeak-f|, frequency center point stability index; 3dB bandwidth: B, frequency concentration index, that is, half-maximum width. The smaller the bandwidth, the purer the signal.

[0060] Step 11: According to the calculation formula of the built-in signal comprehensive quality index Q, the three translation axes (X, Y, Z) and the three rotation axes ( X、 Y. The peak amplitude A, frequency error Δf, and 3dB bandwidth B of the signal Z are calculated separately. When the peak amplitude A, frequency error Δf, and 3dB bandwidth B are calculated separately, the calculation formula for the comprehensive signal quality index Q is: .

[0061] Step 12: Calculate the signal quality index Q for each axis independently, and find the three translation axes (X, Y, Z) and the three rotation axes ( X、 Y. The step position that makes Q maximum in Z) is recorded as X opt , Y opt , Z opt , X opt , Y opt , Z opt ,like Figure 9 shown.

[0062] The automatic adjustment of the focal plane is completed through the above steps for three translation axes (X, Y, Z) and three rotation axes ( X、 Y. The laser interference signal is collected and analyzed in frequency and amplitude, which can automatically determine the optimal position of the focal plane. opt , Y opt , Z opt , X opt , Y opt , Z opt , which can greatly improve the efficiency and accuracy of the installation, alignment and testing of the focal plane of the laser detector of the Fourier interferometer remote sensing instrument.

[0063] In order to achieve the above purpose, the focal plane automatic adjustment device is designed with a laser detector preamplifier circuit to filter the input signal and reduce the focal plane judgment error caused by signal noise. The laser detector preamplifier circuit is used to filter the input signal, see Figure 10 As shown, the laser detector preamplifier circuit includes: Photovoltaic amplifier circuit, receiving weak current signal from laser detector; MFB type high-pass filter circuit to filter out low-frequency noise; Fifth-order Butterworth low-pass filter circuit to suppress high-frequency interference.

[0064] In order to achieve the above purpose, the focal plane automatic adjustment device is designed with a laser detector high-speed AD sampling circuit to digitally process and collect the signal from the laser detector preamplifier circuit. Figure 11 shown.

[0065] To achieve the above purpose, the focal plane automatic adjustment device is designed with a laser detector six-axis translation stage drive circuit. The circuit is implemented by building an H-bridge drive circuit using power MOS tubes. This is used to implement the step-by-step drive operation of the laser detector six-axis translation stage used in the laser detector installation structure. Figure 12 shown.

[0066] Furthermore, for the focal plane automatic adjustment main control module, it can be implemented using controllers such as FPGA, and the internal control automatic adjustment process is as follows Figure 13 As shown. The present invention realizes fully automatic scanning of the detector focal plane by means of six-axis full-degree-of-freedom collaborative optimization, breaking through the limitations of traditional single-axis or three-axis adjustment. It can solve asymmetric problems such as focal plane tilt and offset in complex optical systems and significantly improve the accuracy of the laser signal of the interference system. The present invention also designs a set of intelligent signal quality evaluation system, by analyzing the laser interference signal in three translation axes (X, Y, Z) and three rotation axes ( X、 Y. The comprehensive quality indicator Q on the optical fiber Z) integrates the three key parameters of amplitude (A), frequency error (Δf), and spectral concentration (B): it avoids the risk of misjudgment caused by a single indicator (such as relying solely on amplitude), can quantitatively evaluate signal quality, and ensure the robustness of focal plane positioning. Without the need for optical system transfer functions or prior physical models, quantitative analysis can be achieved directly based on the spectral characteristics of the original interference signal, reducing dependence on system modeling accuracy and simplifying the calibration process. The system is compatible with various types of laser detectors (such as photodiodes, CCDs, etc.) and has strong versatility. The present invention adopts independent scanning of sub-axis and a local optimal combination strategy, which can achieve real-time adjustment and reduce the training costs of professional operators.

[0067] The embodiment of the present invention also provides a method for automatically adjusting the focal plane of a laser detector for a Fourier interferometer remote sensing instrument. When the control system is controlling the entire machine, refer to Figure 13 As shown, the system control process adopted is as follows: Step 1: Start the interferometer system and wait for the laser interferometer signal to stabilize.

[0068] Step 2: Start the automatic focal plane adjustment device and wait for the adjustment device to stabilize.

[0069] Step 3: Calculate the signal frequency of the laser interference signal based on the moving mirror and theoretical formula ; Wherein, the signal frequency of the laser interference signal is The calculation formula is: Where, is the frequency of the interference signal in Hertz (Hz); is the moving mirror speed in meters per second (m / s); is the wavelength of the laser, in meters (m).

[0070] Step 4: Control the six-axis translation stage to move along the translation axis X, according to the minimum step value that the translation stage can support. , each time it moves to a certain position, a high-speed AD is used to collect data on the laser interference signal, and the data is recorded as D x1 to D xn , the translation axis X is from the translation axis X max Move gradually to X min , see Figure 2 shown.

[0071] Step 5: Control the six-axis translation stage to move along the translation axis Y, according to the minimum step value that the translation stage can support. , each time it moves to a certain position, a high-speed AD is used to collect data on the laser interference signal, and the data is recorded as D y1 to D yn , the translation axis Y is from the translation axis Y max Move gradually to Y min , see Figure 3 shown.

[0072] Step 6: Control the six-axis translation stage to move along the translation axis Z according to the minimum step value that the translation stage can support. , each time it moves to a certain position, a high-speed AD is used to collect data on the laser interference signal, and the data is recorded as D z1 to D zn , the translation axis Z is from the translation axis Z max Move gradually to Z min , see Figure 4 shown.

[0073] Step 7: Control the six-axis translation stage along the rotation axis X rotation, according to the minimum step value that the stage can support X, each time it rotates to a certain position, a high-speed AD is used to collect data on the laser interference signal, and the data is recorded as D x1 to D xn , translation axis X from the translation axis X max Gradually move to X min See also Figure 5 shown.

[0074] Step 8: Control the six-axis translation stage along the rotation axis Y rotation, according to the minimum step value that the translation stage can support Y, each time it rotates to a certain position, a high-speed AD is used to collect data on the laser interference signal, and the data is recorded as D y1 to D yn , translation axis Y from the translation axis Y max Gradually move to Y min See also Figure 6 shown.

[0075] Step 9: Control the six-axis translation stage along the rotation axis Z rotation, according to the minimum step value that the translation stage can support Z, each time it rotates to a certain position, a high-speed AD is used to collect data on the laser interference signal, and the data is recorded as D z1 to D zn , translation axis Z from the translation axis Z max Gradually move to Z min See also Figure 7 shown.

[0076] Step 10, the three translation axes (X, Y, Z) and the three rotation axes ( X、 Y. Z) Laser interference signal data D recorded during displacement x1 to D xn 、D y1 to D yn 、D z1 to D zn 、D x1 to D xn 、D y1 to D yn 、D z1 to D zn Perform data feature extraction Taking the optimal position as an example, the laser interference signal data is as follows: Figure 8 shown.

[0077] When performing data feature extraction, three features are extracted from the signal data: peak amplitude A, frequency error Δf, and 3dB bandwidth B; among them: Peak amplitude: A = signal strength index; Frequency error: Δf=|fpeak-f|, frequency center point stability index; 3dB bandwidth: B, frequency concentration index, that is, half-maximum width. The smaller the bandwidth, the purer the signal.

[0078] Step 11: According to the calculation formula of the built-in signal comprehensive quality index Q, the three translation axes (X, Y, Z) and the three rotation axes ( X、 Y. The peak amplitude A, frequency error Δf, and 3dB bandwidth B of the signal Z are calculated separately. When the peak amplitude A, frequency error Δf, and 3dB bandwidth B are calculated separately, the calculation formula for the comprehensive signal quality index Q is: .

[0079] Step 12: Calculate the signal quality index Q for each axis independently, and find the three translation axes (X, Y, Z) and the three rotation axes ( X、 Y. The step position that makes Q maximum in Z) is recorded as X opt , Y opt , Z opt , X opt , Y opt , Z opt ,like Figure 9 shown.

[0080] The above are exemplary embodiments disclosed in the present invention, but it should be noted that various changes and modifications may be made without departing from the scope of the embodiments disclosed in the claims. The functions, steps and / or actions of the method claims according to the disclosed embodiments described herein do not need to be performed in any particular order. In addition, although the elements disclosed in the embodiments of the present invention may be described or required in individual form, they may also be understood as multiple unless expressly limited to the singular.

[0081] It should be understood that, as used herein, the singular form "a" or "an" is intended to include the plural form, unless the context clearly supports an exception. It should also be understood that, as used herein, "and / or" refers to any and all possible combinations of one or more of the items listed in association. The serial numbers of the embodiments disclosed in the above embodiments of the present invention are for descriptive purposes only and do not represent the superiority or inferiority of the embodiments.

[0082] Those skilled in the art should understand that the discussion of any of the above embodiments is merely illustrative and is not intended to limit the scope of the disclosure of the present invention (including the claims) to these examples. Within the spirit of the present invention, the technical features of the above embodiments or different embodiments may be combined, and many other variations exist in different aspects of the above embodiments, which are not provided in detail for the sake of clarity. Therefore, any omissions, modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A laser detector focal plane automatic adjustment device for Fourier interferometer remote sensing instruments, characterized in that: It includes laser detector preamplifier circuit, laser detector high-speed AD sampling circuit, laser detector six-axis translation stage, laser detector six-axis translation stage drive module, and focal plane automatic adjustment main control module; The laser detector preamplifier circuit is used to preamplify and filter the laser interference signal received by the laser detector; The laser detector high-speed AD sampling circuit is used to digitally collect the analog signal amplified by the connected laser detector preamplifier circuit; The laser detector six-axis translation stage carries the laser detector mounting structure and supports degree of freedom adjustment on three translation axes and three rotation axes to achieve focal plane adjustment of the laser detector; The laser detector six-axis translation stage driving module is used to drive the six-axis translation stage to move according to a preset step value; The focal plane automatic adjustment main control module is respectively connected to the laser detector high-speed AD sampling circuit and the laser detector six-axis translation stage drive module, and is used for automatic control of the six-axis translation stage, automatic collection of laser interference signals, automatic analysis of laser interference signals, and drawing of the response curve of the interference signal under the laser focal plane as a function of the focal plane position.

2. The automatic adjustment device for the focal plane of a laser detector for a Fourier interferometer remote sensing instrument according to claim 1, characterized in that: The laser detector is mounted on a six-axis translation platform, which controls the laser detector mounting structure to perform dynamic adjustment on three translation axes and three rotation axes to obtain the optimal focal plane position of the laser detector.

3. The automatic focal plane adjustment device for a laser detector for a Fourier interferometer remote sensing instrument according to claim 2, characterized in that: The focal plane automatic adjustment main control module is used to analyze the frequency and amplitude of the laser interference signal collected by high-speed AD, determine the optimal position of the focal plane, and perform the following steps during automatic adjustment: Start the interferometer system and wait for the laser interferometer signal to stabilize; Start the automatic focal plane adjustment device and wait for the adjustment device to stabilize; The signal frequency of the laser interference signal is calculated based on the moving mirror and theoretical formula ; Control the six-axis translation stage to move along the translation axis X, according to the minimum step value that the translation stage can support , each time it moves to a certain position, a high-speed AD is used to collect data on the laser interference signal, and the data is recorded as D x1 to D xn , the translation axis X is from the translation axis X max Move gradually to X min ; Control the six-axis translation stage to move along the translation axis Y, according to the minimum step value that the translation stage can support , each time it moves to a certain position, a high-speed AD is used to collect data on the laser interference signal, and the data is recorded as D y1 to D yn , the translation axis Y is from the translation axis Y max Move gradually to Y min ; Control the six-axis translation stage to move along the translation axis Z according to the minimum step value that the translation stage can support , each time it moves to a certain position, a high-speed AD is used to collect data on the laser interference signal, and the data is recorded as D z1 to D zn , the translation axis Z is from the translation axis Z max Move gradually to Z min ; Control the six-axis translation stage along the rotation axis X rotation, according to the minimum step value that the stage can support X, each time it rotates to a certain position, a high-speed AD is used to collect data on the laser interference signal, and the data is recorded as D x1 to D xn , translation axis X from the translation axis X max Gradually move to X min ; Control the six-axis translation stage along the rotation axis Y rotation, according to the minimum step value that the translation stage can support Y, each time it rotates to a certain position, a high-speed AD is used to collect data on the laser interference signal, and the data is recorded as D y1 to D yn , translation axis Y from the translation axis Y max Gradually move to Y min ; Control the six-axis translation stage along the rotation axis Z rotation, according to the minimum step value that the translation stage can support Z, each time it rotates to a certain position, a high-speed AD is used to collect data on the laser interference signal, and the data is recorded as D z1 to D zn , translation axis Z from the translation axis Z max Gradually move to Z min ; For three translation axes X, Y, Z and three rotation axes X、 Y. Laser interference signal data D recorded during the displacement of Z x1 to D xn 、D y1 to D yn 、D z1 to D zn 、D x1 to D xn 、D y1 to D yn 、D z1 to D zn Perform data feature extraction; According to the calculation formula of the built-in signal comprehensive quality index Q, the three translation axes X, Y, Z and the three rotation axes are X、 Y. The peak amplitude A, frequency error Δf, and 3dB bandwidth B of Z are calculated respectively; Calculate the signal quality index Q independently for each axis and find the three translation axes X, Y, Z and three rotation axes X、 Y. The step position in Z that maximizes Q is recorded as X opt , Y opt , Z opt , X opt , Y opt , Z opt .

4. The automatic focal plane adjustment device for a laser detector for a Fourier interferometer remote sensing instrument according to claim 3, characterized in that: The signal frequency of the laser interference signal The calculation formula is: Where, is the frequency of the interference signal in Hertz; is the moving mirror speed in meters per second; is the wavelength of the laser in meters.

5. The automatic focal plane adjustment device for a laser detector for a Fourier interferometer remote sensing instrument according to claim 3, characterized in that: When performing data feature extraction, three features are extracted from the signal data: peak amplitude A, frequency error Δf, and 3dB bandwidth B; among them: Peak amplitude: A = signal strength index; Frequency error: Δf=|fpeak-f|, frequency center point stability index; 3dB bandwidth: B, frequency concentration index, that is, half-maximum width. The smaller the bandwidth, the purer the signal.

6. The automatic focal plane adjustment device for a laser detector for a Fourier interferometer remote sensing instrument according to claim 5, characterized in that: When the peak amplitude A, frequency error Δf, and 3dB bandwidth B are calculated separately, the calculation formula for the comprehensive signal quality index Q is: 。 7. The automatic focal plane adjustment device for a laser detector for a Fourier interferometer remote sensing instrument according to claim 1, characterized in that: The laser detector preamplifier circuit is used to filter the input signal, and the laser detector preamplifier circuit includes: Photovoltaic amplifier circuit, receiving weak current signal from laser detector; MFB type high-pass filter circuit to filter out low-frequency noise; Fifth-order Butterworth low-pass filter circuit to suppress high-frequency interference.

8. The automatic focal plane adjustment device for a laser detector for a Fourier interferometer remote sensing instrument according to claim 1, characterized in that: The laser detector high-speed AD sampling circuit is used to digitally process and collect analog signals from the laser detector preamplifier circuit and output digital signals.

9. The automatic focal plane adjustment device for a laser detector for a Fourier interferometer remote sensing instrument according to claim 1, characterized in that: The laser detector six-axis translation stage adopts an H-bridge drive circuit, and realizes bidirectional control of the translation stage stepper motor through a power MOS tube, which is used to perform stepping drive operation on the laser detector six-axis translation stage used by the laser detector mounting structure.

10. A method for automatically adjusting the focal plane of a laser detector for a Fourier interferometer remote sensing instrument, characterized in that: The method is performed based on the automatic adjustment device for the focal plane of a laser detector for a Fourier interferometer remote sensing instrument according to any one of claims 1 to 9, and the method comprises the following steps: Step 1: Start the interferometer system and wait for the laser interferometer signal to stabilize; Step 2: Calculate the theoretical interference frequency ,in is the moving mirror speed, λ is the laser wavelength; Step 3: Control the translation stage to move along the X / Y / Z / θX / θY / θZ axes in sequence, and collect signal data once for each movement step value Δ; Step 4: Extract the characteristic parameters A, Δf, and B of all data; Step 5: Press Calculate the Q value of each axis; Step 6: Positioning Q max The corresponding optimal focal position.

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