In response to the existing test requirements for airborne optoelectronic products, a long-wavelength band (7.5μm ~ 12.0μm) dynamic dual-target simulator was developed. Compared with previous dynamic scene projection equipment. The dynamic dual target simulator realizes the simulation of moving targets by moving target plates of different shapes and sizes at the rear focal plane of the collimating optical system. The two targets are respectively located on the conjugate focal plane of the collimating optical system, and the coupling of the two targets is realized through the beam combiner. The beam combiner can respectively transmit and reflect two infrared targets, so that the two infrared target beams can be efficiently combined into one infrared beam, while ensuring that no ghost images are generated.
In the infrared detection sensitivity test of optoelectronic products, the black body mostly adopts a single black body structure, and the ambient temperature is obtained by the temperature sensor of the black body close to the aperture aperture, not the aperture aperture to simulate the background temperature. Under the condition of large temperature difference, the black body irradiates the back of the aperture aperture for a long time, which will cause the surface temperature of the aperture aperture to rise and introduce large errors. The infrared detection sensitivity test system based on double black body adopts target black body and background black body to achieve accurate simulation of target and background temperature respectively. The target black body is transmitted through the aperture aperture to complete the target radiation simulation, and the background black body is reflected through the aperture aperture to complete the background radiation simulation. The designed infrared detection sensitivity test system has an optical aperture of Θ500mm, a focal length of 4000mm, a temperature adjustment accuracy of 0.01°C, a field of view of 2°, and an exit radiation uniformity better than 90%. It adopts environmental adaptation design to ensure that it can work under a wide temperature range of -55° ~ 70°, which effectively expands the test range of infrared detection sensitivity testing.
KEYWORDS: Video, Infrared imaging, Signal detection, Signal processing, Video processing, Infrared search and track, Infrared detectors, Imaging systems, Target detection
As a passive detection system, the infrared search and tracking (IRST) system is widely used in the search and tracking of high-speed targets. In order to ensure stable tracking of high-speed targets, the infrared search and tracking system has a high image frame rate, and even through the window function of the infrared detector, the image output frame rate can reach hundreds or even thousands of Hz. At the same time, in order to facilitate visual observation, the detection system should also have an analog video display function, and the common analog video frame rate is generally 25 Hz or 30 Hz. Therefore, it is necessary to realize the analog video display of high frame rate video stream through frame rate conversion. Aiming at the above problems, an adaptive frame rate conversion method is proposed and implemented on the infrared imaging hardware platform of the detection system. The experimental results show that the adaptive characteristics of the method have good versatility, and the frame rate conversion can be easily and stably realized.
Aiming at the current testing requirements of optoelectronic products, a long-wave infrared dynamic dual-target simulation system is designed.The optical design of the system adopted a transmissive structure, the dual targets were located on the conjugate focal plane of the optical path, and the dynamic dual targets were realized by a beam combiner.The two-dimensional transportation of the goal was achieved by electric devices.Compared with the static target simulation system, the dual targets could move independently to realize different acceleration and speed curve simulations. In the field of view, the motion curve can be programmed to achieve, and the target position information could be output in real time.The final realization of parallelism was better than 20″, the field of view was 4°, the exit pupil diameter was Φ160mm, the exit pupil distance was 1100mm, the focal length was 800mm, the dynamic target movement speed was 0.02°/s~3°/s, and the acceleration was 0.02°/ s 2~3° /s2 .After a number of product trials, the simulation system meets the current demand for optoelectronic products testing.
Aiming at the current testing requirements of optoelectronic products, a portable target simulation system with adjustable radiation band was designed.The optical design of the system adopted a total reflection structure, and the radiation source adopted a combination of black body and visible light, covering the wavelength band of 0.4 μm to 12 μm.In order to facilitate the use of the product, an electronic shutter was installed to realize the disappearance and appearance of the target. By switching different wavelength filters, the switching and combination of medium wave, long wave, visible light and other radiation bands could be realized. The final design achieved an effective aperture of Φ200mm, a field of view of 2°, a parallel difference of 9", and a focal length of 1500mm.The target simulator works well after delivery
At present, airborne optoelectronic products mostly use multi-sensors (visible light, infrared, laser, etc.) to coordinate the detection, recognition and tracking of threatened targets. Therefore, higher requirements are placed on the optical axis consistency of multi-sensors.In response to this demand, the visible light, laser and infrared astigmatism axis detection equipment suitable for a wide temperature range (-55°C~+70°C) are designed.The collimating optical system of the optical axis detection device adopts a common aperture design, and uses an off-axis parabolic mirror to achieve collimation of the light beam.For a wide temperature environment, the optical system adopts passive athermal design.Compared with the previous independent radiation sources, the multi-band composite radiation source is used to integrate infrared, visible and laser radiation sources, saving space, simplifying the operation steps and reducing the difficulty of use.The optical axis detection equipment needs to be used in the temperature box. Compared with the previous manual operation of the temperature box, this solution uses electric means to realize the optical axis measurement, which greatly improves the use efficiency and reduces the risk of personal injury.The optical axis detection equipment designed finally can control the collimation optical system parallel difference within 10″under wide temperature range and within 6″ under 20°C.
The current semi-physical simulation testing of optoelectronic products requires the simulator to meet the requirements of full band, high accuracy and portability.In response to this demand,a full-band target simulator that can be used on a five-axis turntable was designed.The collimating optical system of the target simulator adopted off-axis reflective structure design, and the radiation simulation source adopted infrared and visible light composite radiation sources; the infrared radiation source and the visible light radiation source adopted the coaxial mode, the structure was compact, and the temperature control accuracy can reach 0.1°C.In order to ensure the imaging quality of optical products, this paper designed the target simulator with exit pupil diameter Φ200mm, exit pupil distance 700mm, parallel difference 8.5", transmittance 0.8@632.8nm. Targeted on different test requirements,designed a variety of shapes such as point hole, four bar, cross and multi-target.Aiming at the problem that the optical axis of the infrared and visible light sensors of the tested photoelectric product is not at the center of rotation of the five-axis turntable, physical translation is used to achieve the connection between the target simulator and the pupil of the sensor optical system of the tested photoelectric product.The target simulator was put into use as soon as the design was completed. After using a variety of optoelectronic products, the feedback was good and met the design requirements.
As a practical test method, semi-physical simulation plays an increasingly important role in the development of airborne photoelectric pods.Since the position of the sensor of different products is different from the center of the rotation, this results in a fixed position scene projector in the semi-physical simulation system that cannot achieve the optical connection with the sensor of the airborne photoelectric pods.Aiming at the problem that the existing semi-physical simulation system scene projector can not move, a set of optical axis translation device is designed.The device can realize the optical axis translation of the scene projector, and the distance and the angle of the optical axis translation can be adjusted, which can effectively realize the optical projector of the scene projector and the airborne photoelectric pod sensor
The maximum ranging distance is a key technical indicator of the pulse laser range finder. It is generally obtained by testing the laser receiving sensitivity of the pulse laser range finder in the laboratory.The existing laser receiving sensitivity test is mainly realized by means of laser analog radiation source and collimating optical system.The laser radiation simulator generally uses a semiconductor laser to transmit the analog laser receiving signal to the focal plane of the collimating optical system through fiber coupling, and then radiates to the receiving aperture of the pulse laser range finder through the collimating optical system. Adjust the intensity of the laser to simulate the energy of the radiation source, and complete the test of the minimum detectable energy, that is, the laser receiving sensitivity.In the actual use process, it is found that the time stability deviation of the radiation power of the semiconductor laser in low-power operation can reach 20%, which is difficult to meet the requirements of use, and after the fiber coupling, the collimation of the collimating optical system, the radiation uniformity is difficult to fulfil requirements.Based on this, this paper designs a pulse laser range finder receiving sensitivity test equipment based on integrating sphere. The system uses the traditional laser radiation analog source plus attenuator to stabilize the laser radiation source.In the case of a pulsed laser range finder as a sensor in combination with a television or infrared sensor, a tungsten halogen lamp is added inside the integrating sphere to provide infrared or television target simulation,then the optical axis of the pulsed laser range finder and collimating optics can be quickly aligned.
Infrared detection distance is a key indicator of infrared search and tracking system. It is generally realized by testing infrared detection sensitivity in the laboratory.The existing infrared detection sensitivity test system uses a single black body configuration, and the target simulation is realized by the point hole target. The background of the target is realized by the target non-transparent area.In actual use, since the target is close to the infrared analog radiation source, the target will gradually become hot as the use time increases, resulting in a smaller radiance temperature difference between the background and the target, which in turn affects the accuracy of the infrared detection sensitivity. Aiming at this situation, this paper designs a dual-black body-based infrared detection sensitivity test system, which achieves the target simulation by the target black body illuminating the spot target, and the background black body illuminates the target to achieve the background simulation. The temperature difference between the target and the black body can be accurately controlled and improved. Infrared detection sensitivity test accuracy.
KEYWORDS: Infrared imaging, Infrared radiation, Thermography, Black bodies, Projection systems, Digital micromirror devices, Imaging systems, Body temperature, Control systems, Medium wave
As a key component of the infrared imaging semi-physical simulation system for airborne optoelectronic products, how to obtain an infrared image closer to the real scene has become the key to the entire infrared imaging system semi-physical simulation system.For infrared dynamic scene projectors, the design of the optical system plays a key role in the imaging fidelity of the infrared simulation scene and target. According to the current usage requirements, this paper designed a medium wave infrared dynamic scene projection system based on DMD. To meet the requirements of the current semi-physical simulation experiments of optoelectronic products, a 1024 × 768 DMD chip was used as the scene modulator.In view of the fact that the dynamic scene projector was to be installed on a turntable, the collimating optical system was designed with a long exit pupil distance and a large exit pupil aperture. The collimating optical system has an exit pupil distance of 600mm, an exit pupil aperture of φ56mm, and a field of view of 6°.The final designed dynamic scene projector could achieve 100Hz dynamic scene generation and could be synchronized externally. The temperature simulation range was -10°C ~ + 300°C, the minimum temperature resolution was 0.1°C, and the gray level was 256. This medium wave dynamic scene projector had been successfully applied to the debugging and testing of several optoelectronic products and semi-physical simulation experiments, which significantly improved the research and development efficiency and shortened the research and development cycle.
As a key device to ensure that the aircraft is not destroyed by missiles, the missile warning system is gradually developing in the direction of multi-band, high sensitivity and global scope.In response to this trend, a dual-wavelength medium-wave infrared radiation simulation source was developed. The simulation source can achieve energy radiation with radiation intensity exceeding 1000 W / Sr in the two windows of the atmospheric window, 2 μm~3 μm and 3μm~ 5μm. The radiant energy in the two bands can be adjusted independently to achieve dual-band composite energy radiation.The dual-band mid-wave infrared radiation simulation source consists of a 2μm ~ 3μm radiation source, a 3μm~5μm radiation source, a louver assembly, and control components. The radiant energy of the two bands of 2μm~ 3μm and 3μm ~ 5μm is realized by two sets of radiation sources, and energy radiation of two bands is realized respectively.The radiation source is composed of a medium wave infrared light source, a collimating reticle, a band pass filter and the like.The collimating reticle is a reflective light bowl structure that uses a metal parabolic mirror and a high reflectivity film layer on its inner layer to form an infinite target beam of a particular field of view. By optimizing the design and combination, the collimated beam has a radiation range of 2° × 2°. The opening and closing of the blinds can be as fast as 15ms. The opening and closing angle of the blinds can be programmed to simulate the radiation energy changes of the incoming missiles.Finally, the resolution of the radiation intensity in the range of 0~150 W/Sr is 0.3 W/Sr, and the resolution in the range of 150W/Sr~1000 W/Sr is 1.5 W/Sr
KEYWORDS: Charge-coupled devices, Mirrors, Light sources, Optical design, Reticles, Light, Light emitting diodes, Autocollimators, Near field optics, Control systems design
The high stiffness self-collimating light pipe is mounted on the single-axis angular vibration table, and is mainly used for the adjustment and debugging of the plane mirror. By monitoring the angle change of the plane mirror, the corresponding test is completed with the photoelectric product..The designed self-collimating light pipe can withstand an angular vibration environment with a vibration frequency of 0.1 Hz to 25 Hz, and the optical axis jitter does not exceed 3" during use.The high stiffness self-collimating light pipe is mainly composed of four parts: optical system, mechanical structure, electronic control system and embedded software.The optical system is mainly composed of a collimating objective lens, a reticle and a light source to form a signal transmitting system, a beam splitter and a signal receiving system including a CCD to realize the transmission and reception of light energy.In order to improve the test accuracy, the optical system collimating objective lens adopts a telephoto optical system, and the main surface of the telephoto optical system is away from the ens group, which can ensure the focal length (200 mm) and the overall size of the optical system.The telephoto optical system consists of a positive lens group and a negative mirror group. The positive and negative lens combination not only reduces the axial dimension of the system but also effectively corrects the spherical aberration of the system.As a high-precision angle measuring system, in order to eliminate the measurement error caused by the axial displacement of the CCD target surface and the focal plane of the optical system, the optical system is designed in the form of an image telecentric optical path. Finally, the angular accuracy can be no more than 2".
The infrared dynamic scene projector is a key component of the infrared imaging seeker semi-physical simulation system. Aiming at the long-wave infrared imaging seeker system, the design idea of long-wave infrared dynamic scene projector with IR-CRT as the core device was proposed. The working principle of IR-CRT was introduced. The optical collimation system was designed. The key parameters such as resolution, distortion, simulated temperature range and uniformity were tested. The dynamic scene projector had been successfully applied to infrared imaging seeker. The semi-physical simulation system had verified the static and dynamic tracking performance of the infrared imaging seeker, which met the requirements of product use, and promoted the product development process.
The visible light dynamic scene projector is a key component of the visible light imaging hardware-in-the-loop(HWIL) simulation test system.With the Digital Micro-mirror Device (DMD) as the key component, a dynamic visible light imaging simulation system was developed which will be used as the hardware in loop simulation platform for a certain type of airborne visible light imaging system.DMD fundamental operating principle and imaging theory are explained thoroughly. According to required,high-brightness RGB LED, aspheric condenser,light rod,relay lens,TIR lens were used to homogenize the illumination light. The optical projection system was specially designed to solve the large diameter and distance of exit pupil.The paper employed mature solution of DMD driving(TI) to achieve scene input,modulation and reproduce. The dynamic scene projector had been successfully applied to the HWIL simulation system of an airborne visible light imaging system, and had high real-time and fidelity, and met the requirements for use
In this paper, an over-top tracking test system for electro-optical detection device is designed, which provides an overtop test environment for electro-optical detection device by using a two-dimensional motion turntable covering the target source of the infrared and visible light bands in a rolling and pitching shafting system. The electro-optical detection device for two-frame configuration provides over-top tracking[1] function and performance testing and verification conditions.
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