Method and device for collecting light scattering signals of particulate matters

Abstract

The invention belongs to the field of particulate matter optical sensing, and particularly relates to a particulate matter light scattering signal acquisition method and device, and the method comprises the steps: controlling scattered light with different scattering angles generated by particulate matter to be detected to reach a digital micromirror device DMD; enabling scattered light of different scattering angle combinations to reach a photoelectric detector by utilizing an on state and an off state of each micromirror in the DMD so as to realize multiple acquisition of scattered light signal intensity by the photoelectric detector and obtain a measurement signal vector S; wherein when a single micro-mirror is turned on, scattered light reaching the micro-mirror is focused on the photoelectric detector through the micro-mirror according to a preset light path, and when the single micro-mirror is turned off, the scattered light reaching the micro-mirror is diffused to an area outside the photoelectric detector; 1 norm minimization is carried out on X = (phi psi)-1S, and X and a sparse domain psi are determined; and performing inversion according to P = psi X to obtain the scattered light intensity P of different scattering angles generated by the particulate matter to be measured. According to the invention, the collection efficiency of scattered light intensity spatial distribution can be improved.

Description

Technical Field

[0001] The present invention belongs to the field of particle optical sensing, and more specifically, relates to a particle light scattering signal acquisition method and device. Background Art

[0002] Particles play an important role in human production and life activities and are closely related to human production and life. In some industrial production, we need to use optical methods to know the relevant information of particles in order to accurately evaluate the relevant performance of particles. In specific applications such as fire detection, it is necessary to obtain the particle size information of particles through optical scattering methods to achieve more accurate fire alarms. In addition, optical scattering methods are also used to perceive atmospheric environment particle information, such as PM2.5 particle measurement. Therefore, optical scattering sensing methods are an important way for humans to obtain information related to particles, and are of great significance to humans' comprehensive understanding and understanding of the living environment.

[0003] Given the great significance of particulate matter, after years of development, there are now a variety of instruments and equipment using different technical principles, and the relevant technical principles for measuring particle size distribution have also made great progress. HELOS from Sympatec, Germany, obtains particle size distribution information by measuring multi-channel Furanhofer diffraction light signals. Such instruments have shown good accuracy in practical applications, but unfortunately, due to their sophisticated and complex structures, such instruments are generally large in size and expensive, which further limits their outdoor measurement applications and large-scale promotion.

[0004] A particle information sensing method based on near-field scattering is disclosed in the Chinese invention patent specification CN109856019 A. This method uses near-field scattering technology to establish the relationship between scattered light intensity and particle information, thereby obtaining the measurement of particle information. A multi-angle particle information detection method is also disclosed in the Chinese invention patent with publication number CN107677573A. Multiple photoelectric converters are used to receive scattered light signals of particles at different angles, thereby sensing the particle size information. Both invention patents are measurement methods based on optical principles. Optical methods have attracted widespread attention in the industry due to their advantages of being non-destructive and fast in measurement speed. Studies have shown that the key to ensuring the measurement accuracy and resolution of optical methods lies in how to collect scattered light signals with a higher number of channels and a higher angular resolution. Because the final measurement results of particle information must be obtained by reversely solving the collected light signals, obtaining higher-dimensional scattered light signals becomes the key to the optical measurement method. Similar views are also expressed in the descriptions of the above two Chinese patents. The former collects near-field scattered light by using a microlens to collect it, in order to extract a high-dimensional scattered light signal with a higher angular resolution from the obtained image. Since the patent disclosure does not provide a specific schematic diagram of the sensor structure, through the introduction and result analysis in the text, the angular spectrum bandwidth of the scattered light signal extracted is only concentrated in a narrow forward range of about 180 degrees at a scattering angle. Therefore, the collected scattered light signal is somewhat single. The latter directly collects high-dimensional scattered light signals by setting a photoelectric receiver array in a fixed or rotating manner. Such a design is easy to implement in structure, but it will lead to a more complex final hardware structure, and it is also necessary to make a trade-off between the accuracy of the measurement results and the complexity of the structure, because a higher measurement accuracy requires more photoelectric receivers, which also leads to further increase in the complexity of the structure. An optional simplified method given in its disclosure is to set the photoelectric receiver on a rotating disk, and when collecting scattered light signals, scattered light signals at different angles are obtained by rotating the disk. However, another problem with this method is that the stability of the particles to be measured must be guaranteed, otherwise the light signals collected by the photoelectric detectors at different measuring angles correspond to particles in different states, which will introduce a large error when inverting the particle information later. From the schematic diagram in the public text, it can be seen that the target dispersion system to be measured in the patent is a liquid dispersion system, which can certainly increase the stability of the particles to be measured, but it also brings limitations to the scope of application and is not conducive to measurement operations.

[0005] In addition, Chinese patent CN110553955A discloses a method for measuring particle size distribution based on scattered light field, using CCD to receive large-scale, high-resolution scattered light angular spectrum information from forward to backward. This method requires a complex imaging structure design. The patent discloses the use of parabolic reflectors and three lenses to shape the scattered light signal and reduce it to the CDD for imaging. In addition, the imaging speed of this method is limited by the performance of the CCD, such as frame rate and response wavelength, which is not conducive to multi-wavelength imaging of scattered light. Summary of the invention

[0006] In view of the defects and improvement needs of the prior art, the present invention provides a method and device for collecting particle light scattering signals, which aims to improve the collection efficiency of the spatial distribution of scattered light intensity.

[0007] To achieve the above object, according to one aspect of the present invention, a method for collecting light scattering signals of particles is provided, comprising:

[0008] The scattered light of different scattering angles generated by the particles to be measured is controlled to reach the digital micromirror device DMD; the two states of on and off of each micromirror in the DMD are used to make the scattered light of different scattering angle combinations reach the photodetector, so as to realize multiple acquisition of the scattered light signal intensity by the photodetector, and obtain the measurement signal vector S; wherein each element in S is the total intensity of the scattered light under the corresponding scattering angle combination; and when a single micromirror is on, the scattered light reaching the micromirror will be focused on the photodetector through the micromirror according to a preset light path, and when the single micromirror is off, the scattered light reaching the micromirror will be diverged to the area outside the photodetector;

[0009] For X = (ΦΨ) -1 S is minimized by 1 norm, thereby determining X and the sparse domain Ψ; the scattered light intensity P of different scattering angles generated by the measured particles is inverted according to P=ΨX to realize the particle light scattering signal acquisition, where Φ represents the measurement matrix, and the value of each row element represents the switching state of each micromirror in the DMD, corresponding to a single acquisition of the scattered light signal intensity by the photodetector.

[0010] Furthermore, the measurement matrix is ​​an orthogonal and symmetric matrix.

[0011] Furthermore, the measurement matrix is ​​determined by the Hadamard matrix to realize the control of the switching state of each micromirror in the DMD.

[0012] The present invention also provides a particle light scattering signal acquisition device, comprising: a light source, a reflector, a digital micromirror device DMD, a photodetector, and a processor;

[0013] The reflector is used to reflect scattered light of different scattering angles generated by the particles to be measured so as to reach the digital micromirror device DMD; the digital micromirror device DMD enables scattered light of different scattering angle combinations to reach the photodetector through the two states of on and off of each micromirror, so as to realize multiple acquisitions of scattered light signal intensity by the photodetector to obtain a measurement signal vector S; wherein each element in S is the total intensity of scattered light under the corresponding scattering angle combination; and when a single micromirror is on, the scattered light reaching the micromirror will be focused on the photodetector through the micromirror according to a preset light path, and when the single micromirror is off, the scattered light reaching the micromirror will be diverged to an area outside the photodetector; the processor is used to process X=(ΦΨ) -1 S is minimized by 1 norm, thereby determining X and the sparse domain Ψ; the scattered light intensity P of different scattering angles generated by the measured particles is inverted according to P=ΨX to realize the particle light scattering signal acquisition, where Φ represents the measurement matrix, and the value of each row element represents the switching state of each micromirror in the DMD, corresponding to a single acquisition of the scattered light signal intensity by the photodetector.

[0014] Furthermore, the measurement matrix is ​​an orthogonal and symmetric matrix.

[0015] Furthermore, the measurement matrix is ​​determined by the Hadamard matrix to realize the control of the switching state of each micromirror in the DMD.

[0016] Furthermore, the reflector is a rotating ellipsoidal mirror.

[0017] In general, the above technical solutions conceived by the present invention can achieve the following beneficial effects:

[0018] (1) The present invention proposes a method for collecting light scattering signals of particles. Through optical path design, a wide range of scattered light is focused on a photodetector. During the focusing process, the scattered light is modulated by a DMD (Digital Micromirror Device) to regularly select part of the scattered light signals. The rapid flipping of the DMD micromirror enables the photodetector to receive a large amount of scattered light signals S in a short time. Furthermore, for X=(ΦΨ) -1 S is minimized by 1 norm, thereby determining X and the sparse domain Ψ; the scattered light intensity P of different scattering angles generated by the measured particles is inverted according to P=ΨX, and the particle light scattering signal is collected, wherein Φ represents the measurement matrix, and the value of each row element represents the switching state of each micromirror in the DMD, corresponding to the one-time collection of the scattered light signal intensity by the photodetector, so as to realize high-resolution scattered light signal collection.

[0019] (2) The present invention proposes to use the Hadamard matrix as the measurement matrix. The Hadamard matrix has the characteristics of orthogonality and symmetry, that is, the n-dimensional Hadamard matrix will contain N orthogonal vectors, where N also represents the number of sampling times; when the value of N is small, the dimension of the sampled signal is also small, which means that the resolution of the sampled scattered light signal is also low; when the value of N is large, the dimension of the sampled signal is also large, which means that the resolution of the sampled scattered light signal is also high. The orthogonal Hadamard matrix has the characteristics of simple generation and good imaging effect, can be generated in real time on hardware, and is suitable for fast flipping of DMD. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 A flowchart of a method for collecting light scattering signals of particles provided in an embodiment of the present invention;

[0021] Figure 2 A spatial distribution diagram of scattered light signals provided by an embodiment of the present invention;

[0022] Figure 3 A diagram of a scattered light single pixel imaging structure provided by an embodiment of the present invention;

[0023] Figure 4 A single-angle scattered light signal diffusion diagram provided by an embodiment of the present invention;

[0024] Figure 5 An optical structure diagram of an optimized particle light scattering signal acquisition device provided in an embodiment of the present invention;

[0025] Figure 6 A physical picture of a particle light scattering signal acquisition device provided in an embodiment of the present invention;

[0026] Figure 7 A flow chart of a device for collecting scattered light signals provided in an embodiment of the present invention;

[0027] Figure 8 A comparison diagram of the scattered light signal and the simulation result provided in the embodiment of the present invention; wherein A is a measured picture of the scattered light, B is a comparison diagram of the measured and simulated scattered light signal, and C is a schematic diagram of the relative error between the measured and simulated scattered light signals;

[0028] Fig. 9 The scattered light images collected at different resolutions are provided in the embodiments of the present invention; wherein A is a scattered light image with a resolution of 16×16, B is a scattered light image with a resolution of 32×32, and C is a scattered light image with a resolution of 64×64. DETAILED DESCRIPTION

[0029] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention. In addition, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0030] Embodiment 1

[0031] A method for collecting light scattering signals of particles, such as Figure 1 As shown, including:

[0032] The scattered light of different scattering angles generated by the particles to be measured is controlled to reach the digital micromirror device DMD; the two states of on and off of each micromirror in the DMD are used to make the scattered light of different scattering angle combinations reach the photodetector, so as to realize multiple acquisition of the scattered light signal intensity by the photodetector, and obtain the measurement signal vector S; wherein each element in S is the total intensity of the scattered light under the corresponding scattering angle combination; and when a single micromirror is on, the scattered light reaching the micromirror will be focused on the photodetector through the micromirror according to a preset light path, and when the single micromirror is off, the scattered light reaching the micromirror will be diverged to the area outside the photodetector;

[0033] For X = (ΦΨ) -1 S is minimized by 1 norm, thereby determining X and the sparse domain Ψ; the scattered light intensity P of different scattering angles generated by the measured particles is inverted according to P=ΨX to realize the particle light scattering signal acquisition, where Φ represents the measurement matrix, and the value of each row element represents the switching state of each micromirror in the DMD, corresponding to a single acquisition of the scattered light signal intensity by the photodetector.

[0034] The present invention proposes a novel particle light scattering signal acquisition method, which specifically acquires multi-dimensional particle light scattering signals by imaging, obtains the optical characterization characteristics of particle information, and realizes the rapid acquisition of scattered light intensity spatial distribution. Through careful optical path design, a wide range of scattered light is focused on the photodetector; during the focusing process, the scattered light is modulated by the DMD (Digital Micromirror Device), and part of the scattered light signal is regularly selected; and the rapid flipping of the DMD micromirror enables the photodetector to receive a large amount of scattered light signals in a short time, realizing high-resolution scattered light signal acquisition.

[0035] According to scattering theory, the spatial distribution of scattered light intensity is related to a lot of information about particles (such as refractive index and particle size distribution), and is an important way to sense particle information. The scattered light intensity of particles can be described as:

[0036] P=C N∫f(d)q(d,m,λ,θ)dd

[0037] Among them, C N is the number concentration of particles, f(d) is the particle size distribution function, q(d,m,λ,θ) is the scattering coefficient of a single particle, d is the particle diameter, m is the refractive index of the particle, λ is the wavelength of the incident light, and θ is the observation angle of the scattered light signal. It can be seen that the intensity of scattered light will be different due to the difference in wavelength λ and observation angle θ, and has inconsistent optical characteristics. These characteristics are an important basis for particle information sensing. Therefore, high-resolution particle scattered light collection is an important basis for realizing accurate particle information sensing. The spatial distribution of scattered light is closely related to the observation angle θ, so spatially distributed scattered light collection is an important way to sense particle information.

[0038] Spatially distributed scattered light collection is to project the scattered light intensity onto the imaging device through imaging, and form a high-resolution scattered light field image with spatial relationship, such as Figure 2 As shown. The existing CCD-based imaging method is to shape the scattered light through an optical lens, and finally project it onto a CCD of matching size. This measurement method is limited by the performance of the CCD, such as the CCD frame rate and the response wavelength range, and it is difficult to quickly and accurately measure the scattered light signal. To this end, the present invention proposes a method and system for scattered light collection based on single-pixel imaging. Single-pixel imaging can receive scattered light signals by using a high-performance photodetector as a detection unit. Compared with CCD, high-performance photodetectors have lower costs and can quickly and accurately receive scattered light signals. Therefore, the present invention adopts a single-pixel imaging method to collect scattered light signals.

[0039] In addition to high-performance photodetectors, this embodiment uses DMD as a spatial modulator to modulate scattered light in different directions, which is eventually received by the photodetector. There are multiple miniature aluminum and closely arranged reflectors on the DMD, and each micromirror has three states, namely, 12° rotation along the diagonal (called "on"), 0° rotation along the diagonal (called "flat"), and -12° rotation along the diagonal (called "off"). The orderly flipping of the different states of the micromirror will selectively modulate the scattered light in different directions, so the scattered light signals received by the photodetector in different flipping states of the DMD are different. In addition, since the flipping rate of the DMD can reach up to 22KHz, the DMD can complete the state switching in a short time, realizing the rapid acquisition of high-resolution scattered light signals.

[0040] According to the single-pixel imaging theory, the scattered light signal P projected on the DMD is modulated by the flip state described by the measurement matrix Φ and becomes the photodetector receiving signal S, which can be specifically described as: S = ΦP.

[0041] Since the states of the micromirrors on the DMD are limited, this embodiment needs to select a binary measurement matrix. It can be preferred that the measurement matrix is ​​an orthogonal and symmetric matrix. It can be further preferred that the measurement matrix Φ is determined by the Hadamard matrix to achieve control of the switching state of each micromirror in the DMD.

[0042] The Hadamard matrix has the characteristics of orthogonality and symmetry, that is, an n-dimensional Hadamard matrix contains N orthogonal vectors, where N also represents the number of sampling times; when the value of N is small, the dimension of the sampled signal is also small, which means that the resolution of the sampled scattered light signal is also low; when the value of N is large, the dimension of the sampled signal is also large, which means that the resolution of the sampled scattered light signal is also high. Among them, H N / 2 is a Hadamard matrix of dimension N / 2, and a 1-dimensional Hadamard matrix H 1 =1, the orthogonal Hadamard matrix has the characteristics of simple generation and good imaging effect. It can be generated in real time on hardware and is suitable for fast flipping of DMD.

[0043] In addition, since the scattered light intensity of spatial distribution has repeated observation angle θ, the scattered light signal of spatial distribution is sparse in a certain domain, which meets the compression condition of compressed sensing and can realize accurate reconstruction of scattered light signal. The specific principle is as follows:

[0044] (1) Compression: The compression process requires transforming the scattered signal P through a sparse domain Ψ. After the transformation, most elements of the signal X are 0. The formula is as follows:

[0045] P=ΨX

[0046] (2) Sampling: The sampling process requires that the measurement matrix Φ is uncorrelated with the matrix Ψ composed of the sparse transformation basis. The sampling formula can be expressed as:

[0047] S=ΦΨX

[0048] (3) Reconstruction: The reconstruction process is to reconstruct the scattered light signal P by solving the 1-norm minimization of the X signal. The specific formula can be expressed as:

[0049] argmin||X||;stS=ΦΨX

[0050] From the formula S = ΦΨX, we know that X = (ΦΨ) -1 S, and minimize the 1 norm of the X signal, that is, (ΦΨ) -1 S is minimized, thereby finding a sparse domain Ψ that satisfies the conditional 1-norm minimization condition (argmin||X||), and substituting it into X = (ΦΨ) -1 Solve for X in S, and finally substitute Ψ and X into the formula P = ΨX to reconstruct the scattered light signal P.

[0051] The scattered light in a large spatial range emitted by the central reaction area will be emitted to the DMD through the rotating elliptical mirror, and then focused on the photodetector through the DMD; wherein the DMD is a component composed of many independent tiny mirrors, and the micromirrors on the DMD can be quickly flipped. The micromirrors have three states, namely, on, off, and flat. This embodiment uses the on and off states of the DMD micromirror; when the micromirror is on, the scattered light will be focused on the photodetector according to the preset optical path; when the micromirror is off, the scattered light will diverge to other places except the photodetector; finally, by quickly opening some DMD micromirrors in a regular manner (Hadamard measurement matrix), some scattered light signals are selected to be focused on the photodetector, and the signal S is measured, as shown in Formula 2. In this embodiment, the measurement matrix is ​​a known Hadamard measurement matrix. It is assumed that the signal P is the product of the sparse domain matrix Ψ and the signal vector X (compression, formula P = ΨX). The vector X has the meaning of minimum modulus, that is, most of the elements in X are 0, and the physical meaning is that it can be approximately represented by a small amount of information in the matrix Ψ. According to the formula S = ΦP, the formula S = ΦΨX (substituting the formula P = ΨX into the formula S = ΦP) is further derived. The conversion relationship between S and the signal X, and according to the above-mentioned constraint condition that the vector X is the smallest modulus, ΦΨ can be further obtained, where the measurement matrix Φ is a preset Hadamard matrix, so Ψ can be solved. After the signal vector X and Ψ are obtained, the scattered light signal can be finally obtained.

[0052] Embodiment 2

[0053] A particle light scattering signal acquisition device, comprising: a light source, a reflector, a digital micromirror device (DMD), a photodetector, and a processor;

[0054] The reflector is used to reflect scattered light of different scattering angles generated by the particles to be measured so as to reach the digital micromirror device DMD; the digital micromirror device DMD enables scattered light of different scattering angle combinations to reach the photodetector through the two states of on and off of each micromirror, so as to realize multiple acquisitions of scattered light signal intensity by the photodetector to obtain a measurement signal vector S; wherein each element in S is the total intensity of scattered light under the corresponding scattering angle combination; and when a single micromirror is on, the scattered light reaching the micromirror will be focused on the photodetector through the micromirror according to a preset light path, and when the single micromirror is off, the scattered light reaching the micromirror will be diverged to an area outside the photodetector; the processor is used to process X=(ΦΨ) -1 S is minimized by 1 norm, thereby determining X and the sparse domain Ψ; the scattered light intensity P of different scattering angles generated by the measured particles is inverted according to P=ΨX to realize the particle light scattering signal acquisition, where Φ represents the measurement matrix, and the value of each row element represents the switching state of each micromirror in the DMD, corresponding to a single acquisition of the scattered light signal intensity by the photodetector.

[0055] Preferably, the measurement matrix is ​​an orthogonal and symmetric matrix. Further preferably, the measurement matrix is ​​determined by a Hadamard matrix to achieve control of the switch state of each micromirror in the DMD. The related technical solution is the same as that of the first embodiment and will not be described in detail here.

[0056] Since single-pixel imaging uses a single photodetector to receive scattered light signals, it is necessary to focus scattered light signals that diverge in different directions on the photodetector. To this end, preferably, this embodiment designs a rotating ellipsoid mirror suitable for scattered light single-pixel imaging, such as Figure 3 As shown. The scattered light in different directions in space is first reflected by the ellipsoidal mirror, then projected on the DMD, and then reflected by the DMD, and finally focused on the photodetector. However, since the actual reaction area of ​​the scattered light is not an ideal point, if the reaction area is set to a sphere with a diameter of millimeters, the focusing effect of the scattered light in different directions will be different, such as Figure 4 The undesirable imaging diagram shown. In order to accurately obtain the scattered light signal, the present invention improves the imaging quality of the scattered light by optimizing the optical path. Specifically, under the set reaction area and device size restrictions, the ellipsoidal surface parameters and the positions of each component are reasonably adjusted to meet the requirements that the scattered light signal in a certain area can be focused in a small area and can be received by the photodetector. The final designed optical path version is as follows Figure 5 Specifically, the ellipsoidal surface parameters of the rotating ellipsoidal mirror include:

[0057] The ellipse equation of the rotating ellipsoidal mirror is The distance between the ellipsoid section and the center of the particle to be measured is 3.1mm, the section aperture is 22.8mm, the center of the particle to be measured is 12mm from the center of the DMD, the DMD tilt angle is 12°, and the scattering angle measurement range is 15°-165°. The photodetector is located beside the rotating ellipsoid mirror and in front of the DMD micromirror reflection surface. The angle between the line connecting the DMD center and the photodetector and the line connecting the center of the particle to be measured and the DMD center is 24°, and the distance between the DMD center and the photodetector is 20.7mm.

[0058] like Figure 6 The picture shown is a real picture. Figure 7 The flow chart of the device collecting scattered light signals. When particles enter the scattered light reaction area of ​​the system, the scattered light intensity generated by them will be focused by the ellipsoidal mirror onto the photodetector; during the measurement process, the micromirrors on the DMD are flipped in order according to the Hadamard matrix, and the photodetector records the scattered light intensity data under different modulation states of the DMD in real time; the scattered light image is reconstructed based on the principle of compressed sensing, and according to the geometric relationship, the scattered light at the same observation angle is distributed along the same radius arc of the left vertex; the scattered light data at the same observation angle are averaged to obtain the scattered light signals at different observation angles.

[0059] To evaluate the system performance, the measured scattered light signal is compared with the scattered light signal calculated from the particle spectrometer measurement results, e.g. Figure 8 shown. Figure 8 A in the figure is the scattered light image collected by single-pixel imaging. Figure 8 There are two shadows in A in the figure. The upper left part is the sample nozzle needle, and the middle part is the interference of incident stray light. Due to the influence of noise, some abnormal noise points appear in the picture; the appearance of these noise points causes the measured scattered light signal to fluctuate, but the overall trend is still consistent with the theoretical scattered light signal, such as Figure 8 The theoretical and measured scattered light signals are compared, as shown in B. Figure 8 As shown in C, the relative error is within ±50%. Fig. 9 The scattered light images obtained by sampling the Hadamard matrix with different resolutions are shown in the figure. Fig. 9 A and B in Fig. 9 The noise of C in the image is more obvious. Since the scattered light image with higher resolution requires more dimensions of Hadamard matrix measurement, and the intensity of the scattered light signal received each time is smaller, the high-resolution image Fig. 9 There are many noise points in C; these noises may mainly come from the environment, such as thermal noise of circuit components, cleanliness of optical device surface and interference of stray light. Although there is the influence of noise, the results of the figure show that this acquisition method can obtain sufficient scattered light signals. In the future, we can optimize the circuit and structure design on this basis to achieve high-precision and fast scattered light acquisition.

[0060] It will be easily understood by those skilled in the art that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for collecting light scattering signals of particles, characterized in that: include: The scattered light of different scattering angles generated by the particles to be measured is controlled to reach the digital micromirror device DMD; the two states of on and off of each micromirror in the DMD are used to make the scattered light of different scattering angle combinations reach the photodetector, so as to realize multiple acquisition of the scattered light signal intensity by the photodetector, and obtain the measurement signal vector S; wherein each element in S is the total intensity of the scattered light under the corresponding scattering angle combination; and when a single micromirror is on, the scattered light reaching the micromirror will be focused on the photodetector through the micromirror according to a preset light path, and when the single micromirror is off, the scattered light reaching the micromirror will be diverged to the area outside the photodetector; For X = (ΦΨ) -1 S is minimized by 1 norm, thereby determining X and the sparse domain Ψ; the scattered light intensity P of different scattering angles generated by the measured particles is inverted according to P=ΨX to realize the particle light scattering signal acquisition, where Φ represents the measurement matrix, and the value of each row element represents the switching state of each micromirror in the DMD, corresponding to a single acquisition of the scattered light signal intensity by the photodetector.

2. A particle light scattering signal acquisition method according to claim 1, characterized in that: The measurement matrix is ​​an orthogonal and symmetric matrix.

3. A particle light scattering signal acquisition method according to claim 2, characterized in that: The measurement matrix is ​​determined by the Hadamard matrix to realize the control of the switch state of each micromirror in the DMD.

4. A particle light scattering signal acquisition device, characterized in that: include: Light source, reflector, digital micromirror device (DMD), photodetector, and processor; The reflector is used to reflect scattered light of different scattering angles generated by the particles to be measured so as to reach the digital micromirror device DMD; the digital micromirror device DMD enables scattered light of different scattering angle combinations to reach the photodetector through the two states of on and off of each micromirror, so as to realize multiple acquisitions of scattered light signal intensity by the photodetector to obtain a measurement signal vector S; wherein each element in S is the total intensity of scattered light under the corresponding scattering angle combination; and when a single micromirror is on, the scattered light reaching the micromirror will be focused on the photodetector through the micromirror according to a preset light path, and when the single micromirror is off, the scattered light reaching the micromirror will be diverged to an area outside the photodetector; the processor is used to process X=(ΦΨ) -1 S is minimized by 1 norm, thereby determining X and the sparse domain Ψ; the scattered light intensity P of different scattering angles generated by the measured particles is inverted according to P=ΨX to realize the particle light scattering signal acquisition, where Φ represents the measurement matrix, and the value of each row element represents the switching state of each micromirror in the DMD, corresponding to a single acquisition of the scattered light signal intensity by the photodetector.

5. The particle light scattering signal acquisition device according to claim 4, characterized in that: The measurement matrix is ​​an orthogonal and symmetric matrix.

6. The particle light scattering signal acquisition device according to claim 5, characterized in that: The measurement matrix is ​​determined by the Hadamard matrix to realize the control of the switch state of each micromirror in the DMD.

7. The particle light scattering signal acquisition device according to claim 4, characterized in that: The reflecting mirror is a rotating ellipsoid mirror.

Images