CN118243228A - Spectrum scanning device based on domestic infrared detector - Google Patents

Abstract

The invention relates to the technical field of infrared testers of photoelectric testers, in particular to a spectrum scanning device based on a domestic infrared detector, which is used for an infrared spectrum radiometer. Comprising the following steps: the detector assembly comprises a domestic infrared detector, a preamplifier and a phase-locked amplifying circuit which are electrically connected in sequence; the optical filter component comprises a gradual change optical filter, a direct current motor I and an encoder; the first direct current motor is used for driving the graded filter to rotate, and the encoder is used for positioning the center wavelength of the graded filter; the chopper modulation component modulates infrared light radiated by a detected target into specific frequency and then enters the detector component; the chopping modulation assembly comprises a chopping plate, a direct current motor II and a photoelectric switch; and the power management circuit is used for supplying power to the whole spectrum scanning device. The invention can realize the analysis of the radiation characteristics of the radiation target in the infrared spectrum range and has the characteristics of high resolution, small volume and high reliability.

Description

A spectrum scanning device based on domestic infrared detector

Technical Field

The invention relates to the technical field of photoelectric testing instruments and infrared testing instruments, and in particular to a spectrum scanning device based on a domestic infrared detector and used for an infrared spectrum radiometer.

Background technique

Infrared spectroradiometer is an important infrared measuring instrument, which is widely used in military, industrial and scientific research fields. It can be used to measure the radiation characteristics of various radiation objects and targets within the infrared spectrum range; it can be used to calibrate and test the performance parameters of FLIR test equipment; it can measure the radiation brightness, radiation temperature, radiation intensity and other parameters of radiation sources, targets and target simulators and their time stability. In practical applications, it can be used to measure the spectral radiation characteristics of aircraft, missiles, rockets and other aircraft, measure the radiation characteristics of engines and tail flames, and can be used to measure the transient infrared radiation intensity and radiation illumination of strong light damage warheads, aviation flash bombs, infrared decoy bombs, and new concept pyrotechnics, and measure the radiation brightness, emissivity and other parameters of camouflage and stealth materials. In the case of assisting other instruments or using existing parameters, it can also measure parameters such as atmospheric transmittance, temperature, humidity, emissivity, reflectivity, etc., to assist in monitoring atmospheric pollution conditions and combustible combustion characteristics.

In the developed countries of Europe and America, infrared spectroradiometers have undergone a leap-forward change in the past two decades, and various types of infrared spectroradiometers have emerged, including non-scanning infrared spectroradiometers and scanning infrared spectroradiometers. Infrared spectroradiometers can be divided into four categories according to the spectral mechanism: gradient filter, prism, grating and Fourier transform. Among them, gradient filter type infrared spectroradiometers have attracted extensive attention from relevant scientific and applied technology research units at home and abroad due to their simple structure, small size, light weight, high measurement accuracy, good stability and high measurement efficiency.

The infrared spectroradiometer has a wide spectral measurement range. The incident radiation is converged to the chopper modulation component through the objective lens component, and after being modulated by the chopper, it alternates with the reference black body radiation through the filter component and enters the detector component. The circuit system is responsible for powering the entire system, controlling the process of the entire system, the rotation of the filter component, the rotation of the chopper modulation component, the synchronous acquisition of the detector component, and the communication with each component. The radiation characteristic analysis and calculation are performed in the measurement control software to obtain the radiation characteristic curve.

However, in actual use, there are still the following technical problems to be solved: 1) The infrared spectroradiometer has a wide spectral measurement range. InSb and MCT detectors are used to cover a wide spectral range. In actual operation, how to ensure the consistency of the optical axis when replacing the detector components. 2) Due to the low transmittance of the system, the infrared radiation is attenuated, the detector output signal is weak, and it is easy to be submerged in the noise background, and the effective spectral information of the target cannot be obtained. 3) The detector output signal and the spectral data are two independent individuals with a certain correlation. It is necessary to ensure that the detector signal and the spectral data are collected synchronously to obtain the spectral curve.

Summary of the invention

The purpose of the present invention is to provide a spectrum scanning device based on a domestic infrared detector, which can be applied to a certain infrared spectrum radiometer, can realize the radiation characteristic analysis of the radiation target within the infrared spectrum range, and has the characteristics of high resolution, small size and high reliability.

In order to solve the above technical problems, the present invention provides a spectrum scanning device based on a domestic infrared detector, comprising:

A detector assembly, including a domestic infrared detector, a preamplifier and a phase-locked amplifier circuit electrically connected in sequence;

The filter assembly comprises a gradient filter, a DC motor 1 and an encoder; the DC motor 1 is used to drive the gradient filter to rotate, and the encoder is used to locate with the central wavelength of the gradient filter;

A chopper modulation component modulates the infrared light radiated by the target to be measured into a specific frequency and then enters the detector component; the chopper modulation component includes a chopper blade, a second DC motor and a photoelectric switch; the second DC motor is used to drive the chopper blade to rotate, and the photoelectric switch is used to detect the modulation frequency;

A power management circuit is used to supply power to the entire spectrum scanning device;

A main control circuit, used to complete the processing of raw data of the detector assembly, communication with each assembly and external communication;

The driving circuit is used to control the chopper modulation component and the filter component to rotate at a constant speed according to a specific frequency.

Preferably, the domestic infrared detector is a single-pixel InSb or MCT detector, and liquid nitrogen cooling is used to improve the signal-to-noise ratio.

Preferably, the preamplifier is used to pre-amplify the signal of the domestic infrared detector.

Preferably, the phase-locked amplifier circuit extracts a weak signal from noise according to the frequency of the chopper modulation component, and outputs the signal of the domestic infrared detector corresponding to the encoder value of the filter component according to the synchronization signal of the filter component.

Preferably, the gradient filter is an ultra-narrow band filter, and the central wavelength varies linearly with the rotation angle.

Preferably, the encoder adopts a 500 line pair encoder.

Preferably, the chopper plate is of a transflective structure and uses an aluminum alloy substrate, and an aluminum outer reflective film is evaporated on the side of the chopper plate facing the reference black body to improve infrared reflectivity.

Preferably, when the filter assembly rotates at a constant speed, the frame synchronization signal of the encoder simultaneously controls the data output of the phase-locked amplifier circuit. The main control circuit matches the output data of the domestic infrared detector with the central wavelength of the gradient filter one by one according to the frame synchronization signal and the correction data of the gradient filter, thereby forming a spectral scanning curve.

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

1) The present invention has a simple structure, small size, light weight, high measurement efficiency, and is suitable for laboratory measurement and field measurement.

2) The present invention can use domestic InSb and MCT detectors for measurement, covering a wide spectral range. There is no need to recalibrate the optical path when replacing the detector, and the operation is simple.

3) The present invention adopts a phase-locked control software correction method to automatically control the synchronization of the filter assembly and the detector data, and has a high level of intelligence.

4) The present invention is applicable to a gradient filter type infrared spectroradiometer and has a broad application prospect.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic diagram of a spectrum scanning device based on a domestic infrared detector according to the present invention.

Detailed ways

The present invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments. The advantages and features of the present invention will become more apparent from the following description. It should be noted that the accompanying drawings are in very simplified form and in non-precise proportions, and are only used to conveniently and clearly assist in explaining the purpose of the embodiments of the present invention.

As shown in FIG. 1 , the embodiment of the present invention specifically discloses that the present invention provides a spectrum scanning device based on a domestic infrared detector, including:

The detector assembly includes a domestic infrared detector, a preamplifier and a phase-locked amplifier circuit which are electrically connected in sequence; the domestic infrared detector is a single-pixel InSb or MCT detector, and liquid nitrogen cooling is used to improve the signal-to-noise ratio. The preamplifier is used to pre-amplify the signal of the domestic infrared detector. The phase-locked amplifier circuit extracts a weak signal from the noise according to the frequency of the chopper modulation component, and outputs the signal of the domestic infrared detector corresponding to the encoder value of the filter component according to the synchronization signal of the filter component.

The filter assembly includes a gradient filter, a DC motor 1 and an encoder; the DC motor 1 is used to drive the gradient filter to rotate, and the encoder is used to locate the central wavelength of the gradient filter; the gradient filter is an ultra-narrowband filter, and the central wavelength changes linearly with the rotation angle. The encoder adopts a 500 line pair encoder. The chopper is a transflective structure and adopts an aluminum alloy substrate. An aluminum outer reflective film is evaporated on the side of the chopper facing the reference black body to improve the infrared reflectivity.

A chopper modulation component modulates the infrared light radiated by the target to be measured into a specific frequency and then enters the detector component; the chopper modulation component includes a chopper blade, a second DC motor and a photoelectric switch; the second DC motor is used to drive the chopper blade to rotate, and the photoelectric switch is used to detect the modulation frequency;

A power management circuit is used to supply power to the entire spectrum scanning device;

A main control circuit, used to complete the processing of raw data of the detector assembly, communication with each assembly and external communication;

The driving circuit is used to control the chopper modulation component and the filter component to rotate at a constant speed according to a specific frequency.

When the filter assembly rotates at a constant speed, the frame synchronization signal of the encoder simultaneously controls the data output of the phase-locked amplifier circuit. The main control circuit matches the output data of the domestic infrared detector with the central wavelength of the gradient filter one by one according to the frame synchronization signal and the correction data of the gradient filter, thereby forming a spectral scanning curve.

The above description is only a description of the preferred embodiments of the present invention, and is not intended to limit the scope of the present invention. Any changes or modifications made by a person skilled in the art in the field of the present invention based on the above disclosure shall fall within the scope of protection of the claims.

Claims (8)

1. A spectrum scanning device based on domestic infrared detector, characterized by comprising:

The detector assembly comprises a domestic infrared detector, a preamplifier and a phase-locked amplifying circuit which are electrically connected in sequence;

The optical filter component comprises a gradual change optical filter, a direct current motor I and an encoder; the first direct current motor is used for driving the graded filter to rotate, and the encoder is used for positioning the center wavelength of the graded filter;

The chopper modulation component modulates infrared light radiated by a detected target into specific frequency and then enters the detector component; the chopping modulation assembly comprises a chopping plate, a direct current motor II and a photoelectric switch; the second direct current motor is used for driving the chopper to rotate, and the photoelectric switch is used for detecting modulation frequency;

the power supply management circuit is used for supplying power to the whole spectrum scanning device;

The main control circuit is used for completing the processing of the original data of the detector assembly, the communication with each assembly and the external communication;

And the driving circuit is used for controlling the chopper modulation assembly and the optical filter assembly to rotate at a constant speed according to a specific frequency.

2. The spectral scanning device based on the domestic infrared detector according to claim 1, wherein the domestic infrared detector is a single-pixel InSb or MCT detector, and a liquid nitrogen refrigeration mode is adopted to improve the signal to noise ratio.

3. A domestic infrared detector-based spectral scanning apparatus as recited in claim 1, wherein the preamplifier is configured to pre-amplify the signal of the domestic infrared detector.

4. The spectral scanning device based on a domestic infrared detector according to claim 1, wherein the phase-locked amplifying circuit extracts weak signals from noise according to the frequency of the chopper modulation assembly, and outputs signals of the domestic infrared detector corresponding to encoder values of the optical filter assembly according to the synchronization signals of the optical filter assembly.

5. The spectral scanning device based on a domestic infrared detector as set forth in claim 1, wherein the graded filter is an ultra-narrow band filter, and the center wavelength varies linearly with the rotation angle.

6. A domestic infrared detector-based spectral scanning apparatus as recited in claim 1, wherein said encoder is a 500-line pair encoder.

7. The spectral scanning device based on the domestic infrared detector as set forth in claim 1, wherein the chopping board has a transflective structure, and an aluminum alloy substrate is used, and an aluminum-plated external reflection film is deposited on a surface of the chopping board facing the reference black body to improve the infrared reflectivity.

8. The spectral scanning device based on a domestic infrared detector according to any one of claims 1 to 7, wherein when the filter assembly rotates at a constant speed, the frame synchronization signal of the encoder simultaneously controls the data output of the lock-in amplifying circuit, and the main control circuit corresponds the output data of the domestic infrared detector to the central wavelength of the gradient filter one by one according to the frame synchronization signal and the correction data of the gradient filter, so as to form a spectral scanning curve.