Multi-mode micro-ballistic impact process observation device and method

Abstract

The invention provides a multi-mode micro-ballistic impact process observation device and method. The multi-mode micro-ballistic impact process observation device comprises a micro-projectile emitter, a light pulse string regulation and control module, a continuous spectrum laser light source, a pulse signal generator, a digital delay trigger, an sCMOS camera and an industrial personal computer. The micro-projectile launcher launches a single micro-projectile to impact the target body; the continuous spectrum laser light source outputs white light with fixed frequency, and the white light enters the light pulse string regulation and control module; the optical pulse string regulation and control module is controlled by the pulse signal generator to be gated, regulates and controls the irradiation area, the gating wavelength and the gating time of an output light source of the continuous spectrum laser light source, and outputs modulation pulse flash to irradiate the micro-projectile and the target body; the sCMOS camera records the process that the micro-projectile impacts the target body through single-frame multiple exposure, and images are sent to the industrial personal computer to be stored. According to the invention, the observation light field is regulated and controlled according to different imaging requirements, the requirements of long and short impact time on the observation light field are considered, and the imaging capability and the imaging quality for the micro-ballistic impact process can be obviously improved.

Description

Technical Field

[0001] The present invention relates to the field of testing the dynamic mechanical properties of materials, and more particularly, to an apparatus and method for observing a multi-mode micro-ballistic impact process. Background Art

[0002] Laser-induced particle impact testing (LIPIT, Lee J H, et al. Science, 2014, 346(6133): 762-766.) is an emerging microscopic-scale impact testing technology that uses pulsed lasers to induce plasmas in metal films to drive elastic films to expand and eject particles. Imaging the flight process of the particles and measuring the velocities of the particles before and after penetrating the target are the keys to ensuring accurate quantitative analysis of the laser-induced particle impact testing technology. Since the flying particles in the laser-induced particle impact testing have characteristics such as micro-scale (size in the micron to sub-micron range), high speed (speed in the km / s range), and instantaneity, the microscopic high-speed imaging and measurement of the particles have high requirements for the spatial resolution and time resolution of the apparatus.

[0003] There are three current measurement technologies that meet the spatio-temporal resolution of LIPIT: ultra-high-speed camera imaging, delayed spectroscopic multiple exposure imaging, and short-time flash multiple exposure imaging. The ultra-high-speed camera imaging method (Hyon J, et al. Materials Today, 2013, 21(5): 514-524.) photographs the flight process of the particles with an ultra-high-speed camera with a frame rate higher than 106 fps. The ultra-high-speed camera used is expensive and does not have a cost advantage. The delayed spectroscopic multiple exposure method (Lee J, et al. Nature Communications, 209, 3(1).) uses a long delay optical path to divide the laser beam into multiple pulses, and uses the pulsed laser obtained by spectroscopic splitting as the illumination flash to make the microscopic CCD camera expose multiple times in the same frame image to record the position information of the particle flight. The optical path of this method is complex and requires a large site, so it has no practical application significance. Short-time flash multiple exposure imaging is a more economical solution. It uses a short-pulse-width flash lamp as the light source and can use bright-field or dark-field imaging methods to make the microscopic CCD camera expose multiple times to record the position information of the particle at multiple moments during flight.

[0004] Patent document CN114966086A (application number: 202210513501.4) discloses a device for measuring the flight speed of microparticles driven by pulsed laser. The pulsed laser emits pulsed laser to drive the microparticle emission platform to emit microparticles. The flash illumination module emits high-frequency flashes to irradiate the microparticles in flight in bright field or dark field mode. The camera module performs long-time exposure and records the position information of the microparticles at different flash moments in one frame of image. The microparticle speed is calculated based on the distance between adjacent bright or dark spots in the image and the flash frequency of the flash lamp. This patent realizes single-microparticle speed measurement based on the dark field imaging method, can simultaneously take into account the bright field imaging method, meets the requirements of micron-level and sub-micron-level spatio-temporal resolution for projectile speed measurement, and can conveniently switch the speed measurement methods of dark field and bright field multiple exposures according to different microparticle sizes. This patent adjusts the repetition frequency of the high-frequency flash lamp to adjust the flash interval to adapt to the selection of projectile speed, and can realize the motion observation of projectiles with a speed above 10 m / s; however, the adjustment range of the repetition frequency of the high-frequency flash lamp itself is limited, and it is difficult to meet the LIPIT requirements for projectile speeds ranging from 0.1 m / s to 1000 m / s, spanning 4 orders of magnitude.

[0005] Therefore, it is urgent to develop a multi-mode microballistic impact process observation method that can adapt to high- and low-speed projectiles, broaden the observation particle speed range, and meet the spatio-temporal resolution requirements of LIPIT tests. Summary of the Invention

[0006] Aiming at the defects in the prior art, the purpose of the present invention is to provide a multi-mode microballistic impact process observation device and method.

[0007] A multi-mode microballistic impact process observation device according to the present invention includes: a microprojectile launcher 1, an optical pulse train modulation module 2, a continuous spectrum laser light source 3, a pulse signal generator 4, a digital delay trigger 5, an sCMOS camera 6, and an industrial control computer 7;

[0008] The microprojectile launcher 1 is used to launch a single microprojectile 8, and the microprojectile 8 is used to impact the target 13; the continuous spectrum laser light source 3 outputs white light with a fixed frequency into the optical pulse train modulation module 2, and the optical pulse train modulation module 2 modulates the light source output by the continuous spectrum laser light source 3 to output modulated pulse flashes, and irradiates the microprojectile 8 and the target 13 with the output modulated pulse flashes; the pulse signal generator 4 is connected to the optical pulse train modulation module 2 and is used to control the short pass of the optical pulse train modulation module 2; the sCMOS camera 6 is used to record the pulse flashes of the microprojectile 8 impacting the target 13; the industrial control computer 7 is used to store the process images of the microprojectile 8 impacting the target 13 recorded by the sCMOS camera 6 and perform image processing;

[0009] The digital delay trigger 5 is respectively connected to the micro-projectile launcher 1, the pulse signal generator 4, and the sCMOS camera 6, and is used for timing regulation among various components.

[0010] Preferably, the optical pulse train regulation module 2 includes: a filter 9, an acousto-optic modulator 10, an optical path extension mirror group 11, and a beam expander 12;

[0011] The continuous spectrum laser light source 3 sequentially passes through the filter 9, the acousto-optic modulator 10, the optical path extension mirror group 11, and the beam expander 12 to adjust the irradiation area, the selected wavelength, and the selected time of the output light source of the continuous spectrum laser light source 3, and outputs a modulated pulsed flash.

[0012] Preferably, the narrow pass wavelength of the filter 9 is selected according to the highest sensitive wavelength of the sCMOS camera 6.

[0013] Preferably, the magnification of the beam expander 12 is selected according to the field of view of the sCMOS camera 6.

[0014] Preferably, the acousto-optic modulator 10 is connected to the pulse signal generator 4, and its modulation mode and optical deflection gating are controlled by the signal generated by the pulse signal generator 4.

[0015] Preferably, the optical path extension mirror group 11 is used to adjust the optical path travel of the beam emitted by the continuous spectrum laser light source 3, separate the direct beam and the selected deflection beam, and eliminate the direct beam that cannot control the selected time.

[0016] Preferably, the sCMOS camera 6 records the pulsed flash of the micro-projectile 8 impacting the target 13 through single-frame multiple exposures.

[0017] Preferably, the gating mode of the optical pulse train regulation module 2 is the high-speed projectile observation mode. The pulse signal generator 4 generates a single square wave signal, and the optical pulse train regulation module 2 is gated at the high level of the square wave. The multiple exposure time intervals of the projectile 8 on the sCMOS camera 6 are controlled by the flash frequency output by the continuous spectrum laser light source 3.

[0018] Preferably, the gating mode of the optical pulse train regulation module 2 is the low-speed projectile observation mode. The pulse signal generator 4 generates multiple pulse signals, and the optical pulse train regulation module 2 is gated at the high level of the pulse. The multiple exposure time intervals of the projectile 8 on the sCMOS camera 6 are determined by the frequency of the pulse signals generated by the pulse signal generator 4, and the number of exposures is controlled by the number of pulse signals generated by the pulse signal generator 4.

[0019] According to a multi-mode micro-ballistic impact process observation method provided by the present invention, based on the above-mentioned multi-mode micro-ballistic impact process observation device, the following steps are performed:

[0020] Step S1: Determine the control mode of the optical pulse train control module 2 according to the launch velocity of the projectile, and preset the output signal of the pulse signal generator 4;

[0021] Step S2: The continuous spectrum laser light source 3 emits an ultrafast white light laser with a fixed frequency;

[0022] Step S3: The output signal of the digital delay trigger 5 triggers the sCMOS camera 6 to start exposure;

[0023] Step S4: The digital delay trigger 5 outputs a signal with a shorter delay time meeting the preset requirements to trigger the micro-projectile launcher 1 to launch the micro-projectile 8 to impact the target 13;

[0024] Step S5: The digital delay trigger 5 outputs a signal with a longer delay time meeting the preset requirements to trigger the pulse signal generator 4 to output a preset signal, controlling the on / off of the optical pulse train control module 2;

[0025] Step S6: The optical pulse irradiated by the optical pulse train control module 2 irradiates the micro-projectile 8 and the target 13, and records the micro-projectile impact process into the same frame image of the sCMOS camera 6 by means of multiple exposures.

[0026] Compared with the prior art, the present invention has the following beneficial effects:

[0027] 1. The present invention adopts the method of short-time flash multiple exposures, and combines a high-frequency flash lamp with an ordinary CCD camera, so that the equipment cost is reduced compared with that of an ultra-high-speed camera;

[0028] 2. The present invention adopts a supercontinuum white light source, which can prevent the influence of strong coherent diffraction during observation compared with a monochromatic laser;

[0029] 3. The present invention realizes the high-speed projectile observation based on the self-frequency of the high-frequency flash and the low-speed projectile observation based on the gating frequency of the acousto-optic modulation gate pulse by adjusting the gating of the acousto-optic modulator;

[0030] 4. The present invention takes into account the applicable range of high-speed / low-speed projectile observation, and can conveniently adjust the high-speed and low-speed observation modes of the velocity measurement system by controlling the single square wave / pulse train output of the pulse signal generator; Brief Description of the Drawings

[0031] By reading the detailed description of the non-limiting embodiments with reference to the following drawings, other features, objects and advantages of the present invention will become more obvious:

[0032] Figure 1 It is a schematic diagram of a multi-mode micro-ballistic impact process observation device.

[0033] Figure 2 Schematic diagram of the observation method for the high-speed projectile impact process

[0034] Figure 3 Schematic diagram of the observation method for the low-speed projectile impact process

[0035] Among them, 1 - micro-projectile launcher; 2 - optical pulse train modulation module; 3 - continuous-spectrum laser light source; 4 - pulse signal generator; 5 - digital delay trigger; 6 - sCMOS camera; 7 - industrial control computer; 8 - micro-projectile; 9 - filter; 10 - acousto-optic modulator; 11 - optical path extended-range mirror group; 12 - beam expander; 13 - target; 14 - single square wave signal; 15 - pulse train signal Specific implementation mode

[0036] The present invention will be described in detail below in conjunction with specific embodiments. The following embodiments will help those skilled in the art to further understand the present invention, but do not limit the present invention in any form. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present invention, several changes and improvements can still be made. These all belong to the protection scope of the present invention

[0037] Embodiment 1

[0038] As Figure 1 shown, a multi-mode micro-ballistic impact process observation device provided by the present invention includes: a micro-projectile launcher 1, an optical pulse train modulation module 2, a continuous-spectrum laser light source 3, a pulse signal generator 4, a digital delay trigger 5, an sCMOS camera 6, and an industrial control computer 7

[0039] The micro-projectile launcher 1 is used to launch a single micro-projectile 8. The micro-projectile 8 impacts the target 13. The continuous-spectrum laser light source 3 outputs white light with a fixed frequency and enters the optical pulse train modulation module 2. The optical pulse train modulation module 2 modulates the irradiation area, selected wavelength, and selected time of the light source output by the continuous-spectrum laser light source 3, and outputs a modulated pulsed flash to irradiate the micro-projectile 8 and the target 13. The pulse signal generator 4 is connected to the optical pulse train modulation module 2 and generates a signal to control the short pass of the optical pulse train modulation module 2. The sCMOS camera 6 records the pulsed flash of the micro-projectile 8 impacting the target 13 through single-frame multiple exposures. The industrial control computer 7 is used to store the process images of the micro-projectile 8 impacting the target 13 recorded by the sCMOS camera 6 and perform image processing; the digital delay trigger 5 is respectively connected to the micro-projectile launcher 1, the pulse signal generator 4, and the sCMOS camera 6, and is used for timing control among various components

[0040] The optical pulse train modulation module 2 includes a filter 9, an acousto-optic modulator 10, an optical path extension mirror group 11 and a beam expander 12; the narrow pass wavelength of the filter 9 is selected according to the highest sensitive wavelength of the sCMOS camera 6, and the magnification of the beam expander 10 is selected according to the field of view of the sCMOS camera 6; the acousto-optic modulator 10 is connected to the pulse signal generator 4, and its modulation mode and optical deflection gating are controlled by the signal generated by the pulse signal generator 4; the optical path extension mirror group 11 is used to adjust the optical path travel of the beam emitted by the continuous spectrum laser source 3, separate the direct beam and the gated deflection beam, and eliminate the direct beam that cannot control the gating time.

[0041] As Figure 2 shown, when the projectile velocity is higher than 10 m / s, the high-speed observation mode is selected. The pulse signal generator 4 generates a single square wave signal, and the optical pulse train modulation module 2 is gated at the high level of the square wave. The multiple exposure time intervals of the projectile 8 on the sCMOS camera 6 are controlled by the flash frequency x MHz output by the continuous spectrum laser source 3.

[0042] As Figure 3 shown, when the projectile velocity is lower than 10 m / s, the low-speed observation mode is selected. The pulse signal generator 4 generates multiple pulse signals, and the optical pulse train modulation module 2 is gated at the high level of the pulse. The multiple exposure time intervals of the projectile 8 on the sCMOS camera 6 are determined by the frequency y Hz of the pulse signals generated by the pulse signal generator 4, and the number of exposures is controlled by the number of pulse signals generated by the pulse signal generator 4. The actual distance corresponding to the shadows in the image is, then the projectile velocity is calculated as y·Δd m / s.

[0043] The present invention takes into account the applicable ranges of high-speed / low-speed projectile observations and can conveniently adjust the high-speed and low-speed observation modes of the velocity measurement system by controlling the single square wave / pulse train output of the pulse signal generator.

[0044] Embodiment 2

[0045] According to a multi-mode micro-ballistic impact process observation method provided by the present invention, based on Embodiment 1, it includes the following steps:

[0046] Step S1: Determine the modulation mode of the optical pulse train modulation module 2 according to the launch velocity of the projectile, and preset the output signal of the pulse signal generator 4;

[0047] Step S2: The continuous spectrum laser source 3 emits an ultrafast white light laser with a fixed frequency;

[0048] Step S3: The digital delay trigger 5 outputs a signal to trigger the sCMOS camera 6 to start exposure;

[0049] Step S4: The digital delay trigger 5 outputs a signal with a shorter delay time to trigger the micro-projectile launcher 1 to launch the micro-projectile 8 to impact the target 13;

[0050] Step S5: The digital delay trigger 5 outputs a signal with a longer delay time to trigger the pulse signal generator 4 to output a preset signal, controlling the on / off of the optical pulse train modulation module 2;

[0051] Step S6: The optical pulse train modulated by the optical pulse train modulation module 2 irradiates the microprojectile 8 and the target 13, and records the microballistic impact process in the same frame image of the sCMOS camera 6 by means of multiple exposures.

[0052] In the description of the present application, it should be understood that the orientation or positional relationship indicated by the terms "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation to the present application.

[0053] Those skilled in the art know that in addition to implementing the systems, devices, and their respective modules provided by the present invention in the form of pure computer-readable program codes, the method steps can be logically programmed to enable the systems, devices, and their respective modules provided by the present invention to be implemented in the form of logic gates, switches, application-specific integrated circuits, programmable logic controllers, and embedded microcontrollers, etc. to achieve the same program. Therefore, the systems, devices, and their respective modules provided by the present invention can be regarded as a kind of hardware component, and the modules included therein for implementing various programs can also be regarded as the structures within the hardware component; the modules for implementing various functions can also be regarded as either software programs for implementing the methods or the structures within the hardware component.

[0054] The specific embodiments of the present invention have been described above. It should be understood that the present invention is not limited to the above specific embodiments, and those skilled in the art can make various changes or modifications within the scope of the claims, which does not affect the essence of the present invention. Without conflict, the embodiments of the present application and the features in the embodiments can be arbitrarily combined with each other.

Claims

1. A multi-mode micro-ballistic impact process observation device, characterized in that: include: Micro-projectile launcher (1), optical pulse train control module (2), continuous spectrum laser light source (3), pulse signal generator (4), digital delay trigger (5), sCMOS camera (6) and industrial computer (7); The micro-projectile launcher (1) is used to launch a single micro-projectile (8), and the micro-projectile (8) is used to impact a target (13); the continuous spectrum laser light source (3) outputs fixed frequency white light to enter the optical pulse train control module (2), and the optical pulse train control module (2) controls the light source output modulated pulse flash output by the continuous spectrum laser light source (3), and irradiates the micro-projectile (8) and the target (13) with the output modulated pulse flash; the pulse signal generator (4) is connected to the optical pulse train control module (2) and is used to control the short-circuit of the optical pulse train control module (2); the sCMOS camera (6) is used to record the pulse flash of the micro-projectile (8) impacting the target (13); the industrial computer (7) is used to store the process image of the micro-projectile (8) impacting the target (13) recorded by the sCMOS camera (6) and perform image processing; The digital delay trigger (5) is respectively connected to the micro-projectile launcher (1), the pulse signal generator (4) and the sCMOS camera (6) for controlling the timing between the components.

2. The multi-mode micro-ballistic impact process observation device according to claim 1, characterized in that: The optical pulse train control module (2) comprises: an optical filter (9), an acousto-optic modulator (10), an optical path range-extending reflector group (11) and a beam expander (12); The continuous spectrum laser light source (3) sequentially passes through the filter (9), the acousto-optic modulator (10), the optical path range-extending reflector group (11) and the beam expander (12) to adjust the irradiation area, gating wavelength and gating time of the output light source of the continuous spectrum laser light source (3) to output a modulated pulse flash.

3. The multi-mode micro-ballistic impact process observation device according to claim 2, characterized in that: The narrow pass wavelength of the optical filter (9) is selected according to the highest sensitive wavelength of the sCMOS camera (6).

4. The multi-mode micro-ballistic impact process observation device according to claim 2, characterized in that: The magnification of the beam expander (12) is selected according to the field of view of the sCMOS camera (6).

5. The multi-mode micro-ballistic impact process observation device according to claim 2, characterized in that: The acousto-optic modulator (10) is connected to the pulse signal generator (4), and its modulation mode and light deflection gating are controlled by signals generated by the pulse signal generator (4).

6. The multi-mode micro-ballistic impact process observation device according to claim 2, characterized in that: The optical path range-extending reflector group (11) is used to adjust the optical path range of the light beam emitted by the continuous spectrum laser light source (3), separate the direct light beam from the gated deflected light beam, and remove the direct light beam whose gate time cannot be controlled.

7. The multi-mode micro-ballistic impact process observation device according to claim 1, characterized in that: The sCMOS camera (6) records the pulse flash of the micro-projectile (8) impacting the target (13) through single-frame multiple exposures.

8. The multi-mode micro-ballistic impact process observation device according to claim 1, characterized in that: The gating mode of the optical pulse train control module (2) is a high-speed projectile observation mode, the pulse signal generator (4) generates a single square wave signal, the optical pulse train control module (2) is gated at a high level of the square wave, and the multiple exposure time intervals of the projectile (8) on the sCMOS camera (6) are controlled by the flash frequency output by the continuous spectrum laser light source (3).

9. The multi-mode micro-ballistic impact process observation device according to claim 1, characterized in that: The gating mode of the optical pulse train control module (2) is a low-speed projectile observation mode, the pulse signal generator (4) generates a plurality of pulse signals, the optical pulse train control module (2) is gated at a pulse high level, the multiple exposure time intervals of the projectile (8) on the sCMOS camera (6) are determined by the frequency of the pulse signal generated by the pulse signal generator (4), and the number of exposures is controlled by the number of pulse signals generated by the pulse signal generator (4).

10. A multi-mode micro-ballistic impact process observation method, characterized in that: The multi-mode microballistic impact process observation device according to any one of claims 1 to 9 performs the following steps: Step S1: determining the control mode of the optical pulse train control module (2) according to the projectile launch speed, and presetting the output signal of the pulse signal generator (4); Step S2: the continuous spectrum laser light source (3) emits a fixed frequency ultrafast white light laser; Step S3: the digital delay trigger (5) outputs a signal to trigger the sCMOS camera (6) to start exposure; Step S4: the digital delay trigger (5) outputs a shorter delay time signal that meets preset requirements to trigger the micro-projectile launcher (1) to launch the micro-projectile (8) to impact the target body (13); Step S5: the digital delay trigger (5) outputs a longer delay time signal that meets preset requirements to trigger the pulse signal generator (4) to output a preset signal, thereby controlling the on and off of the optical pulse train control module (2); Step S6: The light pulses regulated by the light pulse train regulation module (2) irradiate the micro-projectiles (8) and the target (13), and the micro-projectile impact process is recorded in the same frame image of the sCMOS camera (6) by means of multiple exposures.

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