A multi-band active flash imaging method and system

Abstract

The application discloses a kind of multi-band active flash imaging method and system, multi-band active flash imaging method includes: in response to receiving trigger signal, based on the preset timing control strategy, at different time stages, trigger illumination module to emit the transient illumination light of corresponding center wavelength to the region to be measured of energetic material sample;Wherein, illumination module includes at least two different center wavelength short pulse light source;In the synchronous exposure window of short pulse light source, through the detector matched with the center wavelength band, the acquisition signal generated by the region to be measured under the action of transient illumination light is collected, and the image data corresponding to different time stages is obtained based on acquisition signal, and image data is used for energetic material detonation process diagnosis.The application utilizes external controllable short pulse light source to actively intervene in detonation process, overcomes the defect that traditional passive imaging is seriously dependent on target spontaneous radiation intensity, and realizes observation on the whole process of detonation in complex environment.

Description

Technical Field

[0001] This invention belongs to the technical field of optical detection, specifically relating to a multi-band active flash imaging method and system. Background Technology

[0002] In the diagnostic study of high-speed transient processes such as ignition, combustion and detonation of energetic materials, it is usually necessary to obtain dynamic image information of process evolution in order to reveal its physical mechanism.

[0003] Related technologies generally employ continuous observation using a single or fixed wavelength band. However, because the detonation process exhibits different dominant radiation characteristics at different stages, a single wavelength band cannot cover the entire process, resulting in extremely poor imaging quality at some stages. More importantly, traditional methods are mostly passive imaging approaches, heavily relying on the target's own emission or thermal radiation to form images. Under conditions of strong background light interference, severe smoke and dust obstruction, or extremely short event duration, problems such as low signal-to-noise ratio, blurred boundaries, and difficulty in stage identification are easily encountered.

[0004] Therefore, there is an urgent need to provide a multi-band active flash imaging method and system. Summary of the Invention

[0005] The main objective of this invention is to provide a multi-band active flash imaging method and system to overcome the shortcomings of the prior art.

[0006] To achieve the above-mentioned objectives, the present invention adopts the following technical solution: An embodiment of the present invention provides a multi-band active flash imaging method, comprising: In response to receiving a trigger signal, based on a preset timing control strategy, the illumination module is triggered to emit transient illumination light of corresponding center wavelength to the test area of ​​the energetic material sample at different time stages; wherein, the illumination module includes at least two short pulse light sources with different center wavelengths; Within the synchronous exposure window of the short-pulse light source, a detector matched with the center wavelength band is used to acquire the acquisition signal generated by the transient illumination light in the area under test, and image data corresponding to different time stages is obtained based on the acquisition signal. The image data is used for diagnosis of the detonation process of energetic materials.

[0007] In a preferred embodiment, the step of triggering short-pulse light sources with corresponding center wavelengths to emit transient illumination light towards the area under test at different time stages based on a preset timing control strategy includes: Based on the trigger signal, the corresponding short pulse light source and the detector are triggered at different time stages according to a preset delay sequence; Different time stages correspond to different dominant physical characteristics, and the delay sequence is used to match the triggering time of the short pulse light source with different center wavelengths with the occurrence time of the corresponding dominant physical characteristics.

[0008] In a preferred embodiment, the different time stages include the detonation initiation stage, the reaction enhancement stage, and the high-temperature product stage; the at least two short-pulse light sources with different center wavelengths include a visible light short-pulse light source, a near-infrared short-pulse light source, and a mid-infrared short-pulse light source; The short-pulse light source unit of the trigger illumination module emits transient illumination light of the corresponding center wavelength to the test area of ​​the energetic material sample, including: triggering the visible light short-pulse light source in the initial stage of detonation, triggering the near-infrared short-pulse light source in the reaction enhancement stage, and triggering the mid-infrared short-pulse light source in the high-temperature product stage.

[0009] In a preferred embodiment, the trigger illumination module emits transient illumination light corresponding to the center wavelength toward the test region of the energetic material sample, including: The light beams output by the multiple short-pulse light sources with different center wavelengths are coupled to the same illumination optical path and illuminate the area to be tested in a coaxial illumination manner. The acquisition of the signal generated in the area under test under the transient illumination light includes: The acquired signal returned from the area to be tested is split into beams, and the split beams are then fed into the corresponding detector.

[0010] In a preferred embodiment, the acquired signal includes at least one of the reflected signal, scattered signal, transmitted signal, or stimulated response signal generated by the area under test under the transient illumination light; The synchronous exposure window is matched with the pulse width and trigger time of the short pulse light source to complete image acquisition within the duration of the transient illumination light.

[0011] In a preferred embodiment, the image data is used for diagnosis of energetic material detonation processes, including: The image data acquired at different time stages are time-registered, stage-identified, image-enhanced, feature-extracted, and fused to obtain a complete dynamic image sequence and multi-dimensional diagnostic results of the energetic material detonation process.

[0012] In a preferred embodiment, the trigger signal includes at least one of a detonation signal, an ignition signal, a pressure signal, an acoustic signal, or a photoelectric signal.

[0013] Another embodiment of the present invention provides a multi-band active flash imaging system for implementing the above-described multi-band active flash imaging method, comprising: The test area module is used to place energetic material samples and detonation triggering devices; The illumination module includes a short-pulse light source unit for emitting transient illumination light onto the test area of ​​the energetic material sample; The multi-band imaging detection module includes at least two detectors for acquiring the acquisition signal generated by the module in the area under test under the transient illumination light. The timing control module is communicatively connected to the illumination module and the multi-band imaging detection module, respectively, and is used to trigger the illumination module and the corresponding detector at different time stages in response to the trigger signal, based on a preset timing control strategy. The data acquisition and processing module is communicatively connected to the multi-band imaging detection module and is configured to perform synchronous acquisition of multi-channel images, data storage, time calibration, and stage matching.

[0014] In a preferred embodiment, the short-pulse light source unit includes at least two short-pulse light sources with different center wavelengths; the illumination module further includes: The beam transmission and shaping unit is used to collimate, expand, shape, combine or distribute the output beams of each of the short pulse light sources, and guide the processed transient illumination light to the area to be measured. In the multi-band imaging detection module, the response band of the detector is matched with the center wavelength of the short pulse light source; The timing control module is used to trigger the short pulse light source and the corresponding detector at different time stages, respectively, corresponding to the center wavelength.

[0015] In a preferred embodiment, the optical elements used in the beam transmission and shaping unit include at least one of a mirror, a dichroic mirror, a beam combiner, or an optical fiber coupler. The multi-band imaging detection module further includes a band filter component, which is used to perform spectral processing on the acquired signal returned from the area under test, and to guide the spectral-splittered light signal into the corresponding detector; the optical element used in the spectral processing includes at least one of the following: band filter component, beam splitter, dichroic mirror, prism beam splitting system, or diffractive optical element. The timing control module includes at least one of a digital delay generator, an FPGA controller, or a programmable logic controller. The short-pulse light source of the lighting module includes at least one of a laser diode, a semiconductor laser, or a solid-state pulsed laser; The detector of the multi-band imaging detection module includes at least one of a high-speed CCD camera, a high-speed CMOS camera, an enhanced ICCD camera, a near-infrared detector, or a mid-infrared detector.

[0016] Compared with existing technologies, this invention provides a multi-band active flash imaging method and system, constructing an imaging technology system of multi-band active flash illumination, band-matched high-speed detection, and unified timing control. Its beneficial effects are as follows: First, by using external pulse active illumination, it eliminates the dependence of traditional passive imaging on the spontaneous emission intensity of the target, and can still obtain high signal-to-noise ratio images under weak signal, strong background interference, or severe smoke and dust obstruction. Second, by matching and configuring multi-band light sources with corresponding detectors, combined with delay sequence control, it achieves the correspondence of, for example, the detonation stage, dominant features, and observation bands, effectively covering the entire process from the initial structural changes of detonation to the expansion of high-temperature products in the later stage, avoiding the loss of information in a single band. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 This is a flowchart illustrating a multi-band active flash imaging method according to one embodiment of this application.

[0019] Figure 2 This is a structural block diagram of a multi-band active flash imaging system according to one embodiment of this application.

[0020] Figure 3 This is a schematic diagram of the system structure of a multi-band active flash imaging system according to one embodiment of this application. Detailed Implementation

[0021] The invention will be more fully understood through the following detailed description, which should be read in conjunction with the accompanying drawings. Detailed embodiments of the invention are disclosed herein; however, it should be understood that the disclosed embodiments are merely exemplary of the invention, which may be embodied in various forms. Therefore, the specific functional details disclosed herein should not be construed as limiting, but rather as the basis for the claims and as intended to teach those skilled in the art to employ the representative basis of the invention in different ways in any suitable detailed embodiment.

[0022] First, let me explain one application scenario involved in this application: Energetic materials undergo several rapid evolutionary stages during ignition, combustion, and detonation, including the formation of localized high-temperature hotspots, the formation of reaction zones, the establishment of detonation waves, the expansion of high-temperature products, and subsequent product radiation. These processes are typically accompanied by violent energy release, detonation wave propagation, particle ejection, and changes in thermal radiation. They are characterized by short durations, rapid changes, and low repeatability, representing typical high-speed transient physical processes. To reveal the detonation mechanism, energy release patterns, and safety response characteristics of energetic materials, it is urgent to establish experimental diagnostic techniques capable of high temporal and spatial resolution observation of the entire detonation process.

[0023] In current dynamic diagnostics of energetic materials, methods such as high-speed photography, schlieren imaging, shadow imaging, infrared thermography, and spectroscopic diagnostics are commonly used. High-speed photography is suitable for recording the morphology of the explosion fireball, crystal fragmentation, and product ejection processes; schlieren imaging is suitable for observing shock wave propagation and gas density gradient changes; infrared thermography is suitable for acquiring thermal radiation distribution and temperature field information; and spectroscopic diagnostics is suitable for analyzing combustion products and radiation characteristics. While each of these methods has its advantages, they typically only reflect the physical information of a single stage in the detonation process, making it difficult to simultaneously consider multi-dimensional dynamic characteristics such as structural changes, thermal processes, and stage transitions. Furthermore, traditional passive imaging methods usually rely on the target's own emission or thermal radiation to form images. When the target radiation is weak, smoke and dust obscure the image, the background is complex, or the process duration is extremely short, problems such as low signal-to-noise ratio, blurred boundaries, and difficulty in stage identification can easily occur.

[0024] The first category is high-speed visible light photography. This technique typically uses a high-speed CCD or CMOS camera to passively receive the target's emission information in the visible light band, recording the expansion of the explosion fireball, the ejection of products, and the crystal fragmentation process. This type of method has mature equipment and high temporal resolution, but it mainly relies on the target's own visible light radiation. When the emission is weak in the initial stage of detonation or when smoke and dust severely obscure the image, the image quality deteriorates significantly, and it cannot effectively acquire thermal radiation information.

[0025] The second category is schlieren imaging and shadow imaging techniques. These methods utilize the light refraction or brightness changes caused by variations in the medium's density gradient to visualize shock wave propagation, airflow structure, and the explosion wavefront. While this technique can clearly display the shock wave structure, its imaging mechanism relies on refractive index changes and primarily reflects gas flow field information; it cannot directly acquire information such as surface damage to energetic materials, reaction zone structure, and temperature radiation.

[0026] The third category is infrared thermography. This technology uses mid-infrared or long-wave infrared detectors to receive the thermal radiation from the target itself, enabling the measurement of the temperature field and hot spot distribution. It is suitable for studying the expansion of high-temperature products, thermal runaway, and thermal response processes, but its spatial resolution is usually relatively limited, and it is difficult to clearly obtain information on the detonation wavefront profile, particle motion, and early structural changes.

[0027] In summary, existing technologies generally suffer from the following shortcomings: First, most schemes only target a single physical quantity in a single stage, making it difficult to fully cover the entire detonation process; second, passive imaging methods are limited by the target's spontaneous emission intensity, resulting in poor imaging performance in weak signal stages; third, multi-band systems typically lack unified timing control and stage matching mechanisms, making it difficult to accurately correspond to the dynamic characteristics of different detonation stages; fourth, existing technologies have not yet proposed a complete technical solution for staged observation of energetic material detonation processes through active illumination from an external short-pulse light source combined with a multi-band detector. Therefore, it is urgent to propose a new multi-band active flash imaging system and method to address the problems of existing technologies in observing the entire detonation process, stage identification capabilities, and imaging quality under weak signal conditions.

[0028] In existing technologies, optical diagnostics of the ignition, combustion, and detonation processes of energetic materials typically employ techniques such as high-speed visible light photography, schlieren imaging, and infrared thermography. While these techniques can achieve dynamic recording of the detonation process to some extent, they still have significant shortcomings in terms of providing high-quality imaging of the entire detonation process of energetic materials across multiple stages and wavelengths.

[0029] First, most existing technologies employ single-band imaging. For example, high-speed visible light photography relies primarily on the target's own radiation in the visible light band to form images. While it offers good observation capabilities for the expansion of the explosion fireball, the ejection of products, and the crystal fragmentation process, image contrast and clarity significantly decrease when the target is in the initial stage of detonation, a stage with weak spontaneous emission, or a stage severely obscured by smoke and dust, making it difficult to obtain effective information. Infrared thermal imaging technology, although capable of acquiring thermal radiation distribution and temperature field changes, is generally only applicable to high-temperature stages, with limited ability to observe the detonation front contour, structural details, and early dynamic processes. Therefore, existing technologies generally suffer from the problem of limited single-band response range, making it difficult to cover the entire detonation process.

[0030] Secondly, the detonation process of energetic materials exhibits different dominant radiation characteristics at different stages. The initial stage of detonation is more suitable for observing structural changes and leading-edge motion, the intermediate stage is more suitable for observing the reaction enhancement region, and the later stage is more suitable for observing high-temperature products and thermal radiation expansion. However, current technologies typically employ fixed wavelengths and fixed equipment for continuous observation, lacking the ability to select different imaging wavelengths based on the characteristics of different stages. This results in high image quality at some stages but poor imaging effects at others, making it difficult to achieve balanced observation throughout the entire process.

[0031] Furthermore, most existing imaging schemes are passive imaging methods, which rely on the target's own emission or thermal radiation to form an image. When the target's radiation intensity is insufficient, the background light interference is strong, the smoke and dust obscure the image, or the event duration is extremely short, passive imaging methods are prone to problems such as low signal-to-noise ratio, blurred boundaries, and difficulty in stage identification. This is especially true in the early, low-light stage of detonation, where clear and reliable image information is often impossible to obtain.

[0032] Furthermore, while existing schlieren imaging technology can clearly display shock wave propagation and gas density gradient changes, its imaging mechanism is mainly based on refractive index changes and focuses on flow field structure observation. It cannot directly reflect the surface damage, reaction zone evolution, and multi-band radiation characteristics of energetic materials, thus failing to meet the need for multi-dimensional diagnosis of the entire detonation process of energetic materials.

[0033] Based on the shortcomings of the existing technology, it can be understood that the technical solution provided in this application is to provide a multi-band active flash imaging method and system for phased observation of the detonation process of energetic materials. The method uses an external controllable short pulse light source to emit transient illumination light of a specific wavelength to the area to be measured at a predetermined time, and a high-speed detector matching the wavelength synchronously acquires the image, thereby getting rid of the dependence of traditional passive imaging on the spontaneous emission intensity of the target and improving the imaging quality in the weak signal stage.

[0034] The method will be explained first, followed by the system.

[0035] Example 1.

[0036] See Figure 1 This embodiment provides a multi-band active flash imaging method, including: S101, in response to receiving a trigger signal, based on a preset timing control strategy, the illumination module is triggered to emit transient illumination light of corresponding center wavelength to the test area of ​​the energetic material sample at different time stages; wherein, the illumination module includes at least two short pulse light sources with different center wavelengths; Specifically, the trigger signal is used to identify the start of a detonation event, either occurring or about to occur. It can be an initiation command actively issued by an external control device, or a physical quantity signal collected in real time by sensors placed near the area to be measured. Upon receiving the trigger signal, a preset timing control strategy is activated. This timing control strategy can be considered to pre-bind the mapping relationship between the temporal evolution characteristics of the detonation process and the wavelength of the light source. For example, as the detonation reaction progresses, short pulse light sources with different center wavelengths will be triggered sequentially at different time stages.

[0037] The short-pulse light source can be a laser diode, semiconductor laser, or solid-state pulsed laser, which can output transient illumination light (i.e., flash) with high peak power in an extremely short time. Through this active light emission mechanism, the scheme no longer relies on the weak light emission or thermal radiation of the energetic material itself in the early stage of the reaction, thus avoiding the technical problem that passive imaging cannot effectively image in the weak signal stage.

[0038] S102, within the synchronous exposure window of the short pulse light source, a detector matched with the center wavelength band is used to collect the acquisition signal generated by the transient illumination light on the area under test, and image data corresponding to different time stages is obtained based on the acquisition signal. The image data is used for diagnosis of the detonation process of energetic materials.

[0039] Specifically, to prevent severe motion blur in the image caused by high-speed detonation wavefronts or stray particles, the detector's exposure time needs to be strictly limited to the duration of the transient illumination light, forming a synchronous exposure window. Within this window, the detector only receives the optical feedback generated after the external transient illumination light illuminates the area under test. It should be understood that the acquired signal includes not only reflected light from the surface of the area under test, but also transmitted light penetrating smoke or the reaction zone, scattered light from particles, or response signals generated by stimulation. The detector needs to have a spectral response range matched to the emitted light source; for example, a high-speed CCD or CMOS camera is used for visible light pulses, and an infrared focal plane detector is used for infrared pulses. Through band matching, interference from background stray light can be filtered out to the greatest extent, improving the signal-to-noise ratio of the target signal.

[0040] In practical applications, the detector converts the acquired signals (optical signals) into image data (digital signals) and then assigns a precise timestamp to each frame to indicate its corresponding detonation time stage. Because the most suitable wavelength is used for active illumination at different stages, the final image sequence can clearly and continuously reflect the dynamic characteristics of the entire process from early structural breakup to later thermal product expansion.

[0041] This embodiment utilizes the above-described scheme to actively intervene in the detonation process using an externally controllable short-pulse light source, overcoming the shortcomings of traditional passive imaging that heavily relies on the target's spontaneous emission intensity, and enabling observation of the entire detonation process in complex environments.

[0042] In an exemplary embodiment, the step of triggering short-pulse light sources corresponding to the center wavelength to emit transient illumination light towards the area under test at different time stages based on a preset timing control strategy includes: Based on the trigger signal, the corresponding short pulse light source and the detector are triggered at different time stages according to a preset delay sequence; Different time stages correspond to different dominant physical characteristics, and the delay sequence is used to match the triggering time of the short pulse light source with different center wavelengths with the occurrence time of the corresponding dominant physical characteristics.

[0043] More specifically, the different time stages include the initial detonation stage, the reaction enhancement stage, and the high-temperature product stage; the at least two short-pulse light sources with different center wavelengths include visible light short-pulse light sources, near-infrared short-pulse light sources, and mid-infrared short-pulse light sources; The short-pulse light source unit of the trigger illumination module emits transient illumination light of the corresponding center wavelength to the test area of ​​the energetic material sample, including: triggering the visible light short-pulse light source in the initial stage of detonation, triggering the near-infrared short-pulse light source in the reaction enhancement stage, and triggering the mid-infrared short-pulse light source in the high-temperature product stage.

[0044] It can be assumed that in the initial stage of detonation, energetic materials mainly undergo localized high-temperature hotspot formation, crystal fragmentation, and detonation wave establishment. At this time, the reaction zone has just formed, the target's own broad-spectrum spontaneous emission has not yet fully established, and dust obscuring is not yet severe. The dominant physical characteristics of this stage are rapid displacement of the solid-phase interface and structural fragmentation. Therefore, upon receiving the trigger signal, a short-pulse visible light source is first triggered according to a preset delay sequence. The visible light band has extremely high spatial resolution, capable of clearly recording the early wavefront profile, high-speed particle ejection behavior, and structural details of instantaneous crystal fragmentation by capturing reflected or scattered light from the surface of the area under test. If the infrared band is used at this time, on the one hand, the spatial resolution of infrared detectors is usually lower than that of visible light detectors, making it difficult to finely characterize the microstructural fragmentation; on the other hand, the early thermal radiation signal of the target itself is weak, resulting in extremely low contrast in infrared imaging. Therefore, choosing the visible light band in the initial stage of detonation can maximize the acquisition of high-resolution images of the early structural evolution.

[0045] As the reaction progresses rapidly, it enters the reaction enhancement phase. At this stage, the detonation wave propagates fully, accompanied by a violent energy release, generating a large amount of dense smoke and dust particles within the reaction zone, and a strong temperature gradient begins to form. The dominant physical characteristics of this stage are intense chemical reactions and internal thermal processes encased in smoke and dust. If visible light continues to be used at this point, its extremely weak penetration through smoke and dust will easily cause scattering, resulting in complete image obstruction and invalid images. Therefore, according to the time-delay sequence, a near-infrared short-pulse light source is triggered during the reaction enhancement phase. The near-infrared band has a longer wavelength and stronger penetrating power, effectively penetrating a certain concentration of smoke and dust, reducing background noise. Simultaneously, the high-temperature reaction zone in this stage releases specific near-infrared radiation. By combining near-infrared active flash illumination with a band-matched detector, the enhanced radiation image and airflow structure evolution within the reaction zone can be effectively captured, thus overcoming the imaging blind spot caused by smoke and dust obstruction.

[0046] In the later stages of the detonation process, specifically the high-temperature product stage, the intense chemical reactions are largely complete, forming outward-expanding high-temperature gaseous products. The dominant physical characteristics of this stage are intense thermal radiation and temperature field distribution. At this point, a mid-infrared short-pulse light source is triggered. The mid-infrared band is within the sensitive window of thermal radiation and can directly respond to the thermal radiation characteristics of the high-temperature products. Through mid-infrared active illumination and detection, not only can the dynamic morphology of the expanding high-temperature products be obtained, but the temperature field distribution information and hotspot evolution patterns can also be deduced from the stimulated response signal. If visible light is used at this stage, only the luminous outline of the outer fireball can be recorded, and the internal thermal energy distribution cannot be detected.

[0047] Through the above mechanism, this embodiment deeply binds the timing control with the physical characteristics of different detonation stages, and constructs the correspondence between the detonation stage, the dominant characteristics and the observation band. This not only avoids invalid exposure or background interference caused by opening mismatched bands in unsuitable stages, but also enables the most diagnostically valuable information to be extracted adaptively at different time points in a single detonation event, thereby improving the comparability of multi-band data and the accuracy of mechanism analysis.

[0048] It should be understood that the above-described division of different time stages and corresponding band selections are only preferred embodiments. In practical applications, the specific delay time parameters in the delay sequence can be adjusted according to the type of energetic material and its reaction timescale, as long as the principle of matching the triggering time with the occurrence time of the specific dominant physical characteristic is met.

[0049] In an exemplary embodiment, the trigger illumination module emits transient illumination light corresponding to the center wavelength toward the test region of the energetic material sample, including: The light beams output by the multiple short-pulse light sources with different center wavelengths are coupled to the same illumination optical path and illuminate the area to be tested in a coaxial illumination manner.

[0050] Compared to multi-angle illumination, where multiple wavelengths illuminate the test area from different incident angles, the coaxial illumination method ensures that the illumination beams of different wavelengths have essentially consistent illumination axes, fields of view, and spot positions in space. This reduces parallax, shading, localized illumination inhomogeneity, and spatial registration errors caused by differences in incident angles between images of different wavelengths. Especially during rapid dynamic processes such as deflagration, rupture, particle dispersion, or smoke obstruction in energetic material samples, coaxial illumination improves the spatial correspondence and temporal synchronization between images of different wavelengths, facilitating subsequent multi-wavelength image registration, fusion, and quantitative analysis.

[0051] It should be noted that the coaxial illumination method described is a preferred embodiment. Provided that the separation, acquisition, and timing synchronization of illumination signals of different bands can be achieved, multi-incident-angle illumination, multi-path independent illumination, or other equivalent optical path structures can also be used, all of which fall within the scope of protection of this invention.

[0052] Because multiple independent light sources exist, including visible light, near-infrared, and mid-infrared, multi-angle dispersed illumination results in beams of different wavelengths projecting onto the test area at different angles in space. This non-coaxial illumination method leads to complex overlapping shadows, illumination blind spots, and parallax caused by differences in viewing angles on the target surface, resulting in spatial registration errors during subsequent multi-band image fusion. To address this technical problem, this embodiment employs a coaxial illumination design. By using optical elements such as beam combiners, dichroic mirrors, or fiber couplers, all beams of different center wavelengths are completely overlapped in space and guided onto the same optical axis path. Thus, regardless of which wavelength of short-pulse light source is triggered at any detonation stage, the beam illuminates the same absolute coordinate position of the test area along the exact same physical path. This coaxial design fundamentally eliminates spatial deviations in the multi-band illumination path, ensuring completely consistent spatial perspective and illumination uniformity across different bands.

[0053] In an exemplary embodiment, acquiring the acquisition signal generated by the area under test under the transient illumination light includes: The acquired signal returned from the area to be tested is split into beams, and the split beams are then fed into the corresponding detector.

[0054] Specifically, when transient illumination light illuminates the area under test, a return beam carrying physical characteristic information is generated. Since detectors matched to different wavelengths typically have specific spectral response ranges (e.g., high-speed CCD cameras are only sensitive to visible light, while infrared focal plane detectors are only sensitive to the infrared band), directly projecting the mixed beam onto a single detector can lead to spectral crosstalk. Therefore, this embodiment introduces a beam splitting process in the detection optical path. For example, by setting up band filtering components such as beam splitters, dichroic mirrors, prism beam splitting systems, or diffractive optical elements, the returned mixed beam is physically separated according to wavelength. The separated single-band light signals are then guided to their respective detector target surfaces. This symmetrical optical path architecture of coaxial illumination and independent detection after beam splitting not only simplifies the complexity of the hardware structure but also significantly improves the spatial registration accuracy and signal-to-noise ratio of multi-channel images. It should be understood that the optical elements listed above are merely illustrative examples, and any equivalent optical structure capable of achieving multi-wavelength beam combining and beam splitting is within the scope of protection of this embodiment.

[0055] In an exemplary embodiment, the acquired signal includes at least one of the reflected signal, scattered signal, transmitted signal, or stimulated response signal generated by the area under test under the transient illumination light; Specifically, the reflected signal is mainly applicable to surface imaging of opaque or weakly transparent energetic material samples, used to characterize information such as crack initiation, particle exfoliation, surface morphology changes, and reaction front positions. The scattered signal is mainly applicable to scenarios such as sample surface roughening, crystal breakage, particle dispersion, and the formation of smoke or aerosol products, used to characterize the behavior of scattered particles, smoke clusters, scattering boundaries, and reaction zone expansion. The transmitted signal is mainly applicable to thin-sheet samples, samples constrained by transparent windows, or smoke / gas-phase product regions with a certain degree of transmittance, used to obtain information on light intensity attenuation, absorption changes, and structural occlusion within or behind the test area. The stimulated response signal is mainly applicable to scenarios where fluorescence, Raman scattering, photothermal response, characteristic absorption changes, or stimulated emission changes occur under transient illumination excitation in a specific wavelength band, used to extract spectral response information related to material composition, temperature state, or reaction products.

[0056] Depending on the morphology, transparency, reaction stage, and detection purpose of the selected waveband of the energetic material sample, one or more of the above-mentioned acquisition signals can be selected for simultaneous acquisition and joint analysis.

[0057] The synchronous exposure window is matched with the pulse width and trigger time of the short pulse light source to complete image acquisition within the duration of the transient illumination light.

[0058] Because the physical morphology of energetic materials changes drastically at different stages of detonation, a single optical mechanism cannot fully reflect their dynamic characteristics. For example, in the initial stage of detonation, solid particles have not fully reacted. When transient illumination light shines on a sample surface with a certain degree of roughness or a broken crystal surface, it mainly produces diffuse reflection and scattered light. At this time, the detector can capture these reflected and scattered signals to reconstruct the fracture and dispersion process of the surface microstructure with high clarity. In the reaction enhancement stage or the high-temperature product stage, a large number of gaseous products and dense dust form a strong optical blocking layer. At this time, transient illumination light of certain wavelengths (such as near-infrared light) can penetrate the thin dust layer, forming transmitted light or penetrating scattered light carrying information about the internal reaction zone. In addition, under the excitation of transient illumination light in the mid-infrared band, gaseous molecules or products in a high-temperature excited state will undergo specific stimulated responses, generating stimulated response signals containing information about the temperature field and material composition.

[0059] In one exemplary embodiment, the image data is used for diagnosis of energetic material detonation processes, including: The image data acquired at different time stages are time-registered, stage-identified, image-enhanced, feature-extracted, and fused to obtain a complete dynamic image sequence and multi-dimensional diagnostic results of the energetic material detonation process.

[0060] Specifically, since images from different time stages are acquired independently under phased illumination, and there may be slight differences in spatial perspective among the detectors, a preset spatial transformation matrix is ​​first used to perform temporal registration and spatial alignment of the images in each band. Subsequently, based on a preset delay sequence and the visual characteristics of the image (such as texture, contrast, and radiation intensity), stage recognition is performed on each frame of the image to automatically determine whether it belongs to the initial detonation stage, the reaction enhancement stage, or the high-temperature product stage. Based on stage recognition, adaptive image enhancement algorithms (such as local contrast enhancement and non-uniformity correction) are used to highlight specific physical features, taking into account the differences in signal-to-noise ratio, background radiation, and imaging non-uniformity of images in different bands. Preferably, the image enhancement method includes at least one of non-uniformity correction and local contrast enhancement.

[0061] Non-uniformity correction is used to correct spatial grayscale deviations caused by detector response differences, background radiation drift, and pixel response inconsistencies, and is particularly suitable for mid-infrared thermal imaging channels. Local contrast enhancement is used to improve the recognizability of local structures such as crack boundaries, particle edges, smoke and dust outlines, or reaction fronts, and is particularly suitable for visible and near-infrared channels. The image enhancement process does not change the temporal correspondence of the original image and retains the corresponding calibration relationships when quantitative parameters such as temperature, radiation intensity, or spectral absorption are involved.

[0062] During feature extraction, key features are extracted, such as wavefront contour coordinates, reaction zone area, particle motion trajectory, or thermal radiation intensity distribution.

[0063] As an example, the feature extraction includes thresholding, edge detection, connected component analysis, contour fitting, centroid localization, or motion trajectory tracking of the enhanced image to obtain key features related to the dynamic response of energetic materials. These key features include, but are not limited to, reaction zone contour coordinates, hot spot area, location of the highest temperature, average temperature, temperature gradient, crack length, crack propagation direction, particle dispersion trajectory, smoke boundary, wavefront propagation velocity, or radiation intensity distribution.

[0064] Finally, the feature data from multiple bands and stages are fused and analyzed at the data level.

[0065] It can be considered that the fusion analysis is not simply a superposition of images from different bands, but rather, based on time synchronization and spatial registration, mapping the physical features of images from different bands to a unified coordinate system for joint analysis. Specifically, one of the visible light channel, near-infrared channel, or mid-infrared channel can be selected as a reference channel, and other band images can be mapped to the coordinate system of the reference channel through a preset spatial transformation matrix; subsequently, the images from different bands are time-aligned according to the trigger delay, exposure window, and acquisition timestamp of each channel.

[0066] After spatiotemporal registration is completed, pixel-level fusion, feature-level fusion, or data-level fusion can be performed. Pixel-level fusion is used to overlay and display visible light structural boundaries, near-infrared transmission / scattering information, and mid-infrared temperature field distribution in the same image. Feature-level fusion is used to map structural features such as crack tips, particle trajectories, and smoke outlines to hot spot locations, temperature gradients, or radiation intensity distributions. Data-level fusion is used to output quantitative parameters such as reaction zone area, maximum temperature, average temperature, wavefront propagation velocity, particle velocity, and smoke propagation rate. Through the above fusion processing, the structural evolution, thermodynamic state, and reaction process of energetic material samples can be characterized simultaneously in the same spatiotemporal coordinates. For example, the structural boundaries extracted from visible light and the temperature field distribution extracted from mid-infrared light can be overlaid in coordinates to simultaneously display the mapping relationship between structural evolution and thermodynamic state on a single fused image. Through the above complete data processing flow, this embodiment can not only output a complete dynamic image sequence but also output quantitative data containing multi-dimensional diagnostic results such as wave velocity, pressure estimation, and temperature gradient, thereby enhancing the engineering data value for detonation mechanism research.

[0067] The triggering signal includes at least one of the following: detonation signal, ignition signal, pressure signal, acoustic signal, or photoelectric signal.

[0068] In other words, regardless of whether the signal source is a direct control signal (detonation signal, ignition signal) or an indirect detection signal (pressure, acoustic, photoelectric signals), it can provide a unified time zero point for the timing control module.

[0069] Furthermore, regarding the method steps, each step in the flash imaging method described in this invention can be replaced with equivalent methods. For example, imaging of different bands can be performed using either a fully synchronous acquisition method or a phased acquisition method based on time sequence; the division of different stages can be achieved either through a preset time window or through automatic identification of signal features. As long as the correspondence between different stages and different bands can be ultimately achieved, it belongs to the equivalent method of this invention.

[0070] Furthermore, this invention can be extended to include other detection methods, such as adding modules for infrared thermal imaging, spectral analysis, or interferometry, to achieve joint observation of more physical quantities. While such extensions increase system functionality, they still fall under the category of extension schemes based on the core ideas of this invention.

[0071] In summary, the technical solution provided in this embodiment uses an external controllable short-pulse light source to emit transient illumination light of a specific wavelength range to the area under test at a specific moment, and an imaging detector matching the wavelength receives the reflected signal, scattered signal, transmitted signal or stimulated response signal generated by the target within the synchronous exposure time window, thereby obtaining the image information of the object under test at a specific moment or at a specific stage, thus achieving multi-dimensional characterization of the entire detonation process.

[0072] Compared with the prior art, this embodiment has at least the following advantages: Because the method uses a timing control strategy to switch different band illuminations and acquire data synchronously in stages during a single detonation event, it avoids errors caused by repeated experiments and improves the continuity and data consistency between images at different stages.

[0073] Because the method selects light sources of different wavelengths and configures detectors with corresponding sensitive bands based on the dominant radiation characteristics and optimal observation bands of different stages of the detonation process of energetic materials, clear images can be obtained in suitable bands for the initial stage, intermediate reaction stage and the later high-temperature product stage of detonation, thus achieving a more complete and continuous observation of the entire detonation process.

[0074] Because the method uses external active illumination, high-peak short-pulse illumination light is emitted to the area to be tested at a predetermined time, and the image is acquired by a high-speed detector within the synchronous exposure window. The image formation mainly depends on external illumination rather than the radiation of the target itself. Therefore, even in the weak emission stage of the early detonation, in complex background environments, or under the condition of smoke and dust obscuring, image information with high signal-to-noise ratio and high contrast can still be obtained.

[0075] Because the method enables flash sources and detectors of multiple bands to work in a preset time sequence through unified trigger control and precise timing management, and accurately corresponds to different physical stages in the detonation event, the images of each band have a unified time reference. Therefore, it can realize the stage-based correlation analysis of processes such as the formation of the detonation front, the development of the reaction zone, and the expansion of high-temperature products, thereby improving the comparability of multi-band data and the accuracy of mechanism analysis.

[0076] Because the method uses multi-band image joint analysis, it can simultaneously obtain information on structural changes, reaction development, and thermal radiation evolution, enabling comprehensive diagnosis of multiple physical quantities in the detonation process of energetic materials. Compared with related technologies that can usually only obtain single image information or single temperature information, it can provide richer experimental data and provide a more comprehensive basis for detonation mechanism research, safety assessment, and material performance optimization.

[0077] Because the method uses short-pulse flash illumination, it can effectively freeze the transient state of high-speed moving targets and reduce motion blur. It has higher time resolution and dynamic image clarity for rapid processes such as detonation wave propagation, high-speed particle ejection, and instantaneous structural rupture.

[0078] Example 2.

[0079] See Figure 2 This embodiment provides a multi-band active flash imaging system for implementing the multi-band active flash imaging method described in Embodiment 1, comprising: The test area module is used to place energetic material samples and detonation triggering devices; The illumination module includes a short-pulse light source unit for emitting transient illumination light onto the test area of ​​the energetic material sample; The multi-band imaging detection module includes at least two detectors for acquiring the acquisition signals generated by the module in the area under test under the transient illumination light. The at least two detectors can be understood as two separate detectors, or as a combination of a single detector and methods such as rapid filter switching, rotating filter wheels, liquid crystal tunable filters, or electro-optic modulators to achieve the function of two or more detectors, i.e., acquiring information in different bands in a time-division manner. Furthermore, a framing imaging camera, a multi-exposure camera, or a high-speed gated imaging device can also be used to acquire multi-band or multi-stage information. Although the above methods differ in structural form, as long as they can achieve the acquisition of band information corresponding to different stages of detonation, they are all equivalent solutions in this embodiment. The timing control module is communicatively connected to both the illumination module and the multi-band imaging detection module. In response to a trigger signal, and based on a preset timing control strategy, it triggers the illumination module and the corresponding detector at different time stages. Regarding timing control, it is not limited to using a delay generator; programmable logic devices (such as FPGAs), microcontrollers, synchronous triggering modules, or other time control systems can also be used to implement triggering and exposure control for each detector. Although different control methods differ in their implementation, as long as they can achieve the time matching relationship between detectors of different bands, corresponding to different stages of the detonation process, they are all alternative implementations of this invention. The data acquisition and processing module is communicatively connected to the multi-band imaging detection module and is configured to perform synchronous acquisition, data storage, time calibration, and stage matching of multi-channel images. Regarding data acquisition and processing, it is not limited to using a computer for image processing; embedded systems, dedicated image processing hardware, or cloud processing platforms can also be used to achieve time matching and stage analysis of multi-band images. Changes in the data processing method do not affect the implementation of the core technical solution of this invention.

[0080] In one exemplary embodiment, the short-pulse light source unit includes at least two short-pulse light sources with different center wavelengths; the illumination module further includes: The beam transmission and shaping unit is used to collimate, expand, shape, combine or distribute the output beams of each of the short pulse light sources, and guide the processed transient illumination light to the area to be measured. In the multi-band imaging detection module, the response band of the detector is matched with the center wavelength of the short pulse light source; The timing control module is used to trigger the short pulse light source and the corresponding detector at different time stages, respectively, corresponding to the center wavelength.

[0081] In one exemplary embodiment, the optical elements employed in the beam transmission and shaping unit include at least one of a mirror, a dichroic mirror, a beam combiner, or a fiber optic coupler; alternatively, fiber optic splitters, wavelength division multiplexers, prism beam splitting systems, diffractive optical elements, or other optical structures capable of separating signals of different wavelengths may be used. All of the above alternatives can achieve the distribution of radiation signals generated by the same detonation event to different detectors according to wavelength, thereby achieving the technical objective of this invention.

[0082] The multi-band imaging detection module further includes a band filter component, which is used to perform spectral processing on the acquired signal returned from the area under test, and to guide the spectral-splittered light signal into the corresponding detector; the optical element used in the spectral processing includes at least one of the following: band filter component, beam splitter, dichroic mirror, prism beam splitting system, or diffractive optical element. The timing control module includes at least one of a digital delay generator, an FPGA controller, or a programmable logic controller. The short-pulse light source of the lighting module includes at least one of a laser diode, a semiconductor laser, or a solid-state pulsed laser; The detector of the multi-band imaging detection module includes at least one of a high-speed CCD camera, a high-speed CMOS camera, an enhanced ICCD camera, a near-infrared detector, or a mid-infrared detector. Alternatively, photodiode arrays, linear array detectors, multispectral cameras, hyperspectral cameras, or integrated multi-band detection chips can also be used. Any method that can distinguish radiation signals in different wavelength ranges and achieve imaging or equivalent signal acquisition falls under the category of equivalent alternatives of this invention.

[0083] Furthermore, regarding the system structure, the multi-band detection structure described in this invention can be arranged in a spatially separated manner (i.e., multiple detectors are located at different optical path positions) or in an integrated manner (such as a multi-band integrated imaging module). The optical path structure can adopt either a coaxial beam splitting method or a multi-incident angle beam splitting method; as long as it can achieve the separation and acquisition of signals in different bands, it belongs to the equivalent structure of this invention.

[0084] At the device level, each detector, optical element, and control unit can be replaced according to specific application requirements. For example, detectors for different wavelengths can use different material systems (such as silicon-based, InGaAs, InSb, HgCdTe, etc.), optical elements can use different types of filters or beam splitters, and timing control modules can use different control architectures. All of the above substitutions do not change the core technical concept of this invention.

[0085] As an example, see Figure 3The multi-band active flash imaging system of the present invention includes an illumination module (short-pulse light source unit, beam transmission and shaping unit 101), a test area module 115, a multi-band imaging detection module, a timing control module 112, and a data acquisition and processing module 114; wherein, the short-pulse light source unit of the illumination module includes a visible light pulse light source 102, a near-infrared pulse light source 103, a first mid-infrared pulse light source 104, and a second mid-infrared pulse light source 105; the beam transmission and shaping unit 101 includes a reflector 106, used to transmit and control the output beams of each pulse light source and guide them to the test area module 115, i.e., the test area of ​​the energetic material sample; the multi-band imaging detection module includes a band filter component 107 and a near-infrared imaging detector 105. 08. A first mid-infrared imaging detector 109, a second mid-infrared imaging detector 110, and a visible light imaging detector 111; the band filtering component 107 is used to perform beam splitting processing on the response signal returned from the area under test, and to import the split light signals into the corresponding detectors respectively; the timing control module 112 includes a digital delay generator 113, which controls the triggering time of each pulse light source and the synchronous exposure window of each detector through time sequence 1 and time sequence 2 respectively, so that transient illumination light of different wavelengths is emitted at different time stages of a single detonation event and the corresponding detectors are synchronously exposed; the data acquisition and processing module 114 is used to synchronously acquire, time-calibrate, and stage-match the image data output by each detector.

[0086] As another example, a multi-band active flash imaging system mainly includes a pulsed light source unit, a beam transmission and shaping unit, a target area module, a multi-band imaging detection module, a timing control module, and a data acquisition and processing module. All modules and units work collaboratively under the unified control of the timing control module to achieve high temporal and spatial resolution image acquisition at different stages of the energetic material detonation process.

[0087] The pulsed light source unit comprises multiple short-pulse light sources with different center wavelengths, preferably laser diodes (LDs), semiconductor lasers, solid-state pulsed lasers, or other light sources capable of outputting high-peak short-pulse radiation. The operating wavelengths of the light sources can cover the near-infrared, mid-infrared, and visible light ranges to meet the observation needs of different stages during the detonation of energetic materials. Preferably, the visible light band is used to acquire images of the detonation front profile, particle ejection, structural fragmentation, and flame boundary; the near-infrared band is used to acquire images of enhanced radiation in the high-temperature reaction zone; and the mid-infrared band is used to acquire information on the dominant thermal radiation stage and temperature field distribution.

[0088] The beam transmission and shaping unit is used to collimate, expand, shape, switch, combine, or distribute the output beams of each pulsed light source, and guide the illumination light to the area under test. This unit may include collimating lenses, beam expanders, reflecting mirrors, beam splitters, beam combiners, dichroic mirrors, filters, fiber optic couplers, and other equivalent optical elements. Multiple wavelengths of illumination light can be incident on the area under test along the same optical path using coaxial illumination, or they can be used to illuminate the target from different directions using multi-angle illumination to improve the recognition effect of target boundaries, smoke and dust interfaces, and shock wave structures.

[0089] The test area module is used to place energetic material samples and detonation triggering devices. The test object can be a single-element explosive, a mixed explosive, a polymer-bonded explosive, a propellant, a charge structure, or other material systems capable of rapid combustion, explosion, or detonation. Depending on experimental needs, the test area can be equipped with a transparent observation window, a protective cavity, an inert atmosphere, a pressure relief structure, and a safety isolation structure to meet optical observation conditions and experimental safety requirements.

[0090] The timing control module preferably employs a delay generator, FPGA controller, programmable logic controller, or high-speed timing module to control the triggering time, pulse width, emission sequence, and repetition frequency of each pulse light source, as well as the exposure window, gate time, gain, and sampling sequence of each detector, so that illumination and image acquisition in each band accurately correspond to different time stages in the detonation process.

[0091] The multi-band imaging detection module includes at least one high-speed detector matched to the illumination wavelength. Preferably, the detector includes a visible light high-speed CCD / CMOS camera, an enhanced ICCD camera, a near-infrared (high-speed) detector, a mid-infrared (high-speed) detector, a short-wave infrared detector, or other band-sensitive detectors. Each detector can use an independent channel structure to receive signals of its corresponding band, or a single detector can be used in conjunction with filter switching, time-division exposure, or band multiplexing to complete multi-band acquisition. The detector receives the reflected signal (i.e., reflected light), scattered signal (i.e., scattered light), transmitted signal (i.e., transmitted light), or stimulated response signal generated by the area under flash illumination in the area under test, and outputs image data.

[0092] The data acquisition and processing module includes an image acquisition card, a storage module, a control computer, and image processing software, used to complete multi-channel image synchronous acquisition, data storage, time calibration, image enhancement, stage matching, and result output. By jointly analyzing images of different wavebands, dynamic information such as wavefront propagation, structural fragmentation, flame development, hot spot formation, and high-temperature product expansion during the detonation process of energetic materials can be obtained.

[0093] The system operates as follows: First, based on the type of energetic material to be tested, the detonation timescale, and the target observation parameters, a pulsed light source of appropriate wavelength and a matching detector are selected, and optical path alignment and system calibration are completed. Then, the timing control module sets the trigger delay, pulse width, and detector exposure window for each pulsed light source. For example, visible light short-pulse illumination can be triggered in the initial stage of detonation, and a high-speed visible light CCD records the detonation front and structural changes; near-infrared pulsed illumination can be triggered in the reaction enhancement stage, and a near-infrared CCD records the evolution of the reaction zone; mid-infrared pulsed illumination can be triggered in the high-temperature thermal radiation stage, and a mid-infrared CCD records the temperature field and hot spot distribution. Each light source and detector operates automatically according to a preset timing sequence, thereby acquiring image information from multiple time stages and wavelength ranges in a single detonation event. Finally, the data acquisition and processing module completes image time registration, stage identification, image enhancement, feature extraction, and fusion analysis to form a complete dynamic image sequence and multi-dimensional diagnostic results for the entire detonation process.

[0094] Because it employs active illumination, clear and reliable transient image information can still be obtained even under conditions of complex backgrounds, insufficient spontaneous emission, severe smoke and dust obstruction, or extremely short event durations. Therefore, compared to traditional passive high-speed photography or passive infrared thermal imaging techniques, it has higher stage resolution, temporal resolution, and environmental adaptability. In summary, this invention proposes a novel active flash imaging technology approach that, through multi-band short-pulse illumination and synchronous high-speed detection, achieves high-quality image acquisition of different stages of the detonation process of energetic materials. This technology can be widely applied in detonation mechanism research, safety assessment, energetic material performance testing, and other high-speed transient event diagnosis fields.

[0095] Compared with the prior art, this embodiment has at least the following advantages: Because the system constructs a multi-band active flash imaging system covering the visible light, near-infrared to mid-infrared range, and is equipped with high-speed detectors that match each illumination wavelength, clear images can be obtained in appropriate bands during the initial detonation stage, intermediate reaction stage and later high-temperature product stage. Compared with existing single-band imaging equipment, this significantly improves the completeness and continuity of observation of the entire detonation process.

[0096] Because the system adopts an external active flash illumination structure, it emits high-peak short-pulse illumination light to the area to be tested at a predetermined time, and the high-speed detector completes the image acquisition within the synchronous exposure window. The image formation mainly depends on external illumination rather than the target's own radiation. Therefore, even in the weak emission stage of the early detonation, in complex background environments, or under the condition of smoke and dust obscuring, it can still obtain image information with high signal-to-noise ratio and high contrast, which significantly improves the imaging stability and usability.

[0097] Because the system integrates multi-band illumination units, imaging detection units, timing control modules, and data processing units into a unified system, it achieves multi-channel collaborative work through a unified control architecture, reducing manual synchronization and repetitive calibration work between multiple independent systems, lowering system operation complexity, and improving experimental efficiency and test repeatability.

[0098] Because the system uses a short-pulse (flash illumination) light source, it can effectively freeze the transient state of high-speed moving targets and reduce motion blur. It has higher time resolution and dynamic image clarity for rapid processes such as detonation wave propagation, high-speed particle ejection, and instantaneous structural rupture.

[0099] Because the system adopts a modular structure design, the wavelength, pulse width, triggering sequence and detector type of the flash source can be flexibly adjusted according to different types of energetic materials, charge structures and experimental targets, so as to adapt to different experimental conditions and observation needs, and has high engineering application value.

[0100] Although the invention has been described with reference to illustrative embodiments, those skilled in the art will understand that various other changes, omissions, and / or additions can be made without departing from the spirit and scope of the invention, and that elements of the described embodiments can be substituted with substantially equivalents. Furthermore, many modifications can be made without departing from the scope of the invention to adapt particular situations or materials to the teachings of the invention. Therefore, this document is not intended to limit the invention to the specific embodiments disclosed for carrying out the invention, but rather to include all embodiments falling within the scope of the appended claims.

Claims

1. A multi-band active flash imaging method, characterized in that, include: In response to receiving a trigger signal, based on a preset timing control strategy, the illumination module is triggered to emit transient illumination light of corresponding center wavelength to the test area of ​​the energetic material sample at different time stages; wherein, the illumination module includes at least two short pulse light sources with different center wavelengths; Within the synchronous exposure window of the short-pulse light source, a detector matched with the center wavelength band is used to acquire the acquisition signal generated by the transient illumination light in the area under test, and image data corresponding to different time stages is obtained based on the acquisition signal. The image data is used for diagnosis of the detonation process of energetic materials.

2. The multi-band active flash imaging method according to claim 1, characterized in that, The preset timing control strategy triggers short-pulse light sources of corresponding center wavelengths to emit transient illumination light towards the area under test at different time stages, including: Based on the trigger signal, the corresponding short pulse light source and the detector are triggered at different time stages according to a preset delay sequence; Different time stages correspond to different dominant physical characteristics, and the delay sequence is used to match the triggering time of the short pulse light source with different center wavelengths with the occurrence time of the corresponding dominant physical characteristics.

3. The multi-band active flash imaging method according to claim 2, characterized in that, The different time stages include the initial detonation stage, the reaction enhancement stage, and the high-temperature product stage; the at least two short-pulse light sources with different center wavelengths include visible light short-pulse light sources, near-infrared short-pulse light sources, and mid-infrared short-pulse light sources; The short-pulse light source unit of the trigger illumination module emits transient illumination light of the corresponding center wavelength to the test area of ​​the energetic material sample, including: triggering the visible light short-pulse light source in the initial stage of detonation, triggering the near-infrared short-pulse light source in the reaction enhancement stage, and triggering the mid-infrared short-pulse light source in the high-temperature product stage.

4. The multi-band active flash imaging method according to claim 1, characterized in that, The trigger illumination module emits transient illumination light of the corresponding center wavelength to the test area of ​​the energetic material sample, including: The light beams output by the multiple short-pulse light sources with different center wavelengths are coupled to the same illumination optical path and illuminate the area to be tested in a coaxial illumination manner. The acquisition of the signal generated in the area under test under the transient illumination light includes: The acquired signal returned from the area to be tested is split into beams, and the split beams are then fed into the corresponding detector.

5. The multi-band active flash imaging method according to claim 1, characterized in that, The acquired signal includes at least one of the reflected signal, scattered signal, transmitted signal, or stimulated response signal generated by the area under test under the transient illumination light; The synchronous exposure window is matched with the pulse width and trigger time of the short pulse light source to complete image acquisition within the duration of the transient illumination light.

6. The multi-band active flash imaging method according to claim 1, characterized in that, The image data is used for diagnosis of energetic material detonation processes, including: The image data acquired at different time stages are time-registered, stage-identified, image-enhanced, feature-extracted, and fused to obtain a complete dynamic image sequence and multi-dimensional diagnostic results of the energetic material detonation process.

7. The multi-band active flash imaging method according to claim 1, characterized in that, The trigger signal includes at least one of the following: detonation signal, ignition signal, pressure signal, acoustic signal, or photoelectric signal.

8. A multi-band active flash imaging system for implementing the multi-band active flash imaging method of claim 1, characterized in that, include: The test area module is used to place energetic material samples and detonation triggering devices; The illumination module includes a short-pulse light source unit for emitting transient illumination light onto the test area of ​​the energetic material sample; The multi-band imaging detection module includes at least two detectors for acquiring the acquisition signal generated by the module in the area under test under the transient illumination light. The timing control module is communicatively connected to the illumination module and the multi-band imaging detection module, respectively, and is used to trigger the illumination module and the corresponding detector at different time stages in response to the trigger signal, based on a preset timing control strategy. The data acquisition and processing module is communicatively connected to the multi-band imaging detection module and is configured to perform synchronous acquisition of multi-channel images, data storage, time calibration, and stage matching.

9. The multi-band active flash imaging system according to claim 8, characterized in that, The short-pulse light source unit includes at least two short-pulse light sources with different center wavelengths; the illumination module also includes: The beam transmission and shaping unit is used to collimate, expand, shape, combine or distribute the output beams of each of the short pulse light sources, and guide the processed transient illumination light to the area to be measured. In the multi-band imaging detection module, the response band of the detector is matched with the center wavelength of the short pulse light source; The timing control module is used to trigger the short pulse light source and the corresponding detector at different time stages, respectively, corresponding to the center wavelength.

10. The multi-band active flash imaging system according to claim 9, characterized in that, The optical elements used in the beam transmission and shaping unit include at least one of a mirror, a dichroic mirror, a beam combiner, or an optical fiber coupler. The multi-band imaging detection module further includes a band filter component, which is used to perform spectral processing on the acquired signal returned from the area under test, and to guide the spectral-splittered light signal into the corresponding detector; the optical element used in the spectral processing includes at least one of the following: band filter component, beam splitter, dichroic mirror, prism beam splitting system, or diffractive optical element. The timing control module includes at least one of a digital delay generator, an FPGA controller, or a programmable logic controller. The short-pulse light source of the lighting module includes at least one of a laser diode, a semiconductor laser, or a solid-state pulsed laser; The detector of the multi-band imaging detection module includes at least one of a high-speed CCD camera, a high-speed CMOS camera, an enhanced ICCD camera, a near-infrared detector, or a mid-infrared detector.

Images