Non-contact algae online detection system and method thereof

Abstract

The invention relates to a non-contact algae on-line detection system and a method thereof. The system comprises: a housing; the measuring cylinder is obliquely arranged in the shell, and the measuring cylinder is provided with a horizontally arranged measuring opening; the light source emitting assembly is located on the upper side of the measuring opening, the light source driving plate is electrically connected with the light source, the glass sheet and the emitting optical axis of the light source emitting assembly form an included angle of 45 degrees, the reference light detector is arranged on the side, reflecting light, of the glass sheet, and the emitting lens is arranged on the side, refracting light, of the glass sheet. The light beam of the light source is positioned below the liquid level of the measurement opening through a focus converged by the emission lens; the fluorescence detection assembly is located on the upper side of the measurement opening, the receiving circuit board is electrically connected with the receiving detector, the receiving diaphragm and the receiving lens are sequentially arranged on the side, close to the measurement opening, of the receiving detector, the emitting optical axis of the light source emitting assembly is perpendicular to the receiving optical axis of the fluorescence detection assembly, and the intersection point is located on the lower side of the liquid level of the measurement opening. Therefore, non-contact algae detection is realized.

Description

Technical Field

[0001] This invention relates to the field of algae detection equipment, and in particular to a non-contact online algae detection system and method. Background Technology

[0002] Algae have a dual impact on water quality. Through photosynthesis, they increase dissolved oxygen, promote water metabolism, and provide food for zooplankton. In appropriate quantities, they can maintain ecological balance. However, when water is polluted, leading to excessive nitrogen and phosphorus levels, or when conditions such as high temperature and strong light cause algae to proliferate explosively, it becomes crucial to monitor algae in real time to understand their current status. Currently, fluorescence detection is the most commonly used method for algae monitoring.

[0003] Algae detection instruments based on the fluorescence properties of algae currently have two usage methods. One method involves manually holding the instrument to the detection point and placing it in the water for timed monitoring. This method is time-consuming, labor-intensive, and carries the risk of drowning. The other method involves placing the instrument in the water at the test point for real-time online monitoring, with data uploaded in real time. However, online monitoring instruments are susceptible to contamination by algae and microorganisms due to the detector being immersed in water, requiring frequent cleaning. If cleaning is not timely or thorough, the detection data may be unstable and unreliable. Therefore, neither of these methods meets the current needs for routine algae monitoring. Summary of the Invention

[0004] The purpose of this invention is to provide a non-contact online algae detection system and method, wherein the non-contact online algae detection system has the characteristics of non-contact detection and has good applicability.

[0005] To achieve the above objectives, the present invention adopts the following technical solution: A non-contact online algae detection system includes: a shell; A measuring cylinder is inclinedly disposed within the housing, and the measuring cylinder has a horizontally disposed measuring opening; A light source emitting assembly, located above the measurement opening, includes a light source driving board, a light source, a reference photodetector, a glass sheet, and an emitting lens. The light source driving board is electrically connected to the light source. The glass sheet is set at a 45° angle to the emitting optical axis of the light source emitting assembly. The reference photodetector is located on the side of the glass sheet that reflects light, and the emitting lens is located on the side of the glass sheet that refracts light. The focal point of the light beam from the light source, converged by the emitting lens, is located below the liquid surface of the measurement opening. The fluorescence detection component, located above the measurement opening, includes a receiving circuit board, a receiving detector, a receiving aperture, and a receiving lens. The receiving circuit board is electrically connected to the receiving detector. The receiving aperture and the receiving lens are sequentially arranged on the side of the receiving detector near the measurement opening. The emission optical axis of the light source emitting component is perpendicular to the receiving optical axis of the fluorescence detection component, and the intersection point is located below the liquid surface of the measurement opening.

[0006] Preferably, the light source emitting assembly further includes an emitting aperture, an emitting quartz glass plate, and an emitting heating plate. The emitting aperture is disposed between the light source and the glass plate. The emitting quartz glass plate is disposed on the side of the emitting lens facing the measuring opening. The emitting heating plate is fixed to the emitting quartz glass plate.

[0007] Preferably, the fluorescence detection assembly further includes a filter, a receiving quartz glass plate, and a receiving heating plate. The filter is disposed between the receiving detector and the receiving aperture. The receiving quartz glass plate is disposed on the side of the receiving lens facing the measuring opening. The receiving heating plate is fixed to the receiving quartz glass plate.

[0008] Preferably, there are two light sources, which are symmetrically arranged on the light source driver board.

[0009] Preferably, the measuring cylinder includes a cylinder body and an overflow cylinder, the measuring opening is formed on the upper side of the cylinder body, the overflow cylinder is sleeved outside the cylinder body, and an overflow cavity is formed between the overflow cylinder and the cylinder body.

[0010] Preferably, a non-contact online algae detection method includes the following steps: S1. Conduct a survey of monitoring points in the target water area, and generate point deployment planning data based on the hydrological conditions of the water area and potential algal bloom areas; install a non-contact online algal detection system according to the deployment planning data, adjust the tilt angle of the measuring tube inside the shell so that the measuring opening is horizontally attached to the liquid surface, start the water inlet, overflow and sludge discharge circuit of the measuring tube to build a self-cleaning measuring water path, and simultaneously complete the position calibration of the light source emission component and the fluorescence detection component, and generate system deployment parameter data and steady-state data of the measuring water path; S2. Based on the system deployment parameter data and the steady-state data of the measured water circuit, start the light source driver board to drive and control the symmetrically set dual light sources to generate multi-wavelength modulated pulse excitation light; limit the beam diffusion angle through the emission aperture, and after being refracted by the glass sheet, the beam is focused by the emission lens to the preset detection point below the liquid surface. At the same time, using the 45° reflection characteristic of the glass sheet, the light source intensity reference signal is collected by the reference photodetector. Combined with the water mist removal status of the emission heating plate, the light source excitation parameter data and emission stability monitoring data are generated. S3. Based on the excitation parameter data of the light source, the fluorescence signal generated by the algae at the detection point is focused by the receiving lens of the fluorescence detection component. After being filtered by the receiving aperture, it passes through the receiving quartz glass plate and the filter in sequence. The receiving detector converts the fluorescence light signal into a weak electrical signal, which is transmitted to the receiving circuit board for first-stage filtering and amplification. Then, it is amplified by second-stage amplification to improve the signal-to-noise ratio and generate noise-reduced fluorescence electrical signal data. S4. Based on the transmission stability monitoring data and the noise reduction fluorescence electrical signal data, the effective signal matching the excitation light is extracted and modulated by the synchronous demodulation module of the receiving circuit board. The analog signal is converted into a digital signal by the analog-to-digital conversion module. The preset algae concentration calibration formula is called, and the light source attenuation data monitored by the reference photodetector is combined to automatically compensate for the measurement results. The concentration values ​​of various types of algae are calculated respectively, and multi-dimensional algae concentration preliminary measurement data are generated. S5. Verify the self-cleaning effectiveness of the measuring cylinder based on the steady-state data of the water path; calculate turbidity data by collecting water body scattered light signals through infrared light source, and perform turbidity compensation correction on the initial measurement data of multi-dimensional algae concentration; combine historical monitoring data to perform time-series trend analysis, determine the algae proliferation rate and outbreak risk level, and generate the final algae concentration detection data, classification ratio data and water quality safety early warning data.

[0011] Preferably, S1 includes: Based on the hydrological characteristics of the water area and the distribution map of potential algal bloom areas, and combined with the application scenarios of the detection system, a differentiated deployment plan for the monitoring points is formulated, and the deployment planning data for the monitoring points is generated; based on the deployment planning data for the monitoring points, the fixed installation of the non-contact online algal detection system is completed. The water inlet circuit, overflow circuit, and sludge discharge circuit of the measuring cylinder are activated to construct a dynamic self-cleaning measuring water circuit. The water flow and stability of the water circuit are monitored in real time, and the initial data of the water circuit operation are generated. Simultaneously, the position of the light source emitting component and the fluorescence detection component are calibrated. Laser positioning technology is used to ensure that the emitting optical axis is perpendicular to the receiving optical axis and that the intersection point falls precisely in the preset detection area below the liquid surface. The calibration parameters are recorded. The system integrates installation parameters, calibration parameters, and initial water circuit operation data to generate system deployment parameter data; and continuously monitors the operation status of the self-cleaning measurement water circuit. After the flow rate and liquid level stabilize, it generates steady-state data of the measurement water circuit.

[0012] Preferably, S2 includes: The microcontroller outputs a PWM modulation signal to drive the light source to generate multi-wavelength modulated pulse excitation light, generating light source modulation control data; the emission aperture is used to precisely limit the beam spread angle of the multi-wavelength modulated pulse excitation light, generating collimated beam data. The collimated beam is refracted by a highly transparent glass sheet at a 45° angle to the emission optical axis and then transmitted to the emission lens. The emission lens converges the refracted multi-wavelength beam into a focused beam and projects it onto a preset detection point below the liquid surface to generate focused excitation light data. Simultaneously, by utilizing the reflective properties of the glass sheet, part of the excitation light is reflected to the reference photodetector to collect the light source intensity reference signal and generate the original intensity data of the light source; the emitting heating plate is activated to monitor the surface temperature and water mist status of the emitting quartz glass sheet in real time and generate water mist removal status data. By integrating light source modulation control data, focused excitation light data, original light source intensity data, and water mist removal status data, light source excitation parameter data and emission stability monitoring data are generated.

[0013] Preferably, S3 includes: The fluorescence signal at the detection point is precisely focused through the receiving lens of the fluorescence detection component to generate focused fluorescence signal data; the focused fluorescence signal is filtered by the receiving aperture to remove stray light from non-target angles and generate directional fluorescence signal data. The directional fluorescence signal passes through the receiving quartz glass plate and the red cutoff filter in sequence to further filter out interference signals and generate pure fluorescence signal data; The receiving detector converts pure fluorescence signal data into a weak electrical signal to generate raw fluorescence electrical signal data; the raw fluorescence electrical signal data is then transmitted to the receiving circuit board, where high-frequency noise is removed and the signal strength is enhanced by a first-stage filter and amplification circuit to generate a first-stage amplified fluorescence electrical signal data. The amplified fluorescence electrical signal data is processed by a two-stage amplification circuit to generate noise-reduced fluorescence electrical signal data.

[0014] Preferably, S4 includes: Based on the PWM waveform parameters in the light source modulation control data, the noise-reduced fluorescent electrical signal data is synchronously demodulated, and an effective electrical signal matching the frequency of the modulated excitation light is extracted to generate synchronous effective electrical signal data. The analog-to-digital converter module converts the synchronous effective electrical signal data from analog to digital, generating fluorescent digital signal data; the reference detector, following the same processing procedure, converts the original intensity data of the light source into digital intensity data of the light source, generating emission light source attenuation monitoring data. Call the preset algae concentration calibration formula: Chl=a×VR+b, input the voltage value VR corresponding to the fluorescence digital signal data, and combine it with the slope a and intercept b previously calibrated by standard algae solution to preliminarily calculate the algae concentration value; Based on the attenuation monitoring data of the emitted light source, the initially calculated algae concentration value is automatically compensated and corrected, and the concentration values ​​of various types of algae are calculated separately to generate multi-dimensional preliminary algae concentration data.

[0015] Preferably, S5 includes: Analyze relevant parameters to determine whether there is any contamination residue on the inner wall of the measuring cylinder and the measuring opening, and generate self-cleaning effectiveness verification data; If the verification data shows a risk of contamination, initiate an emergency cleaning procedure to eliminate measurement deviations caused by water contamination; if the verification is successful, retain the initial multi-dimensional algae concentration data. The infrared LED light source is activated to emit infrared light into the detection area, and the scattered light signal generated by particulate matter in the water is received to generate scattered light detection data; the turbidity value of the water is calculated based on the scattered light detection data to generate water turbidity correction parameters. The initial multidimensional algae concentration data is corrected using water turbidity correction parameters to generate corrected algae concentration data. Historical monitoring data stored in the system's built-in memory is retrieved to perform time-series trend analysis on the corrected algae concentration data and calculate the algae proliferation rate and slope of change. By combining algal proliferation rate, the proportion of various algal species, and water quality safety threshold, the risk level of algal outbreak is determined; the final algal concentration detection data, classification proportion data, and water quality safety early warning data are generated by integrating and correcting algal concentration data, algal species classification proportion data, and risk level determination results, and then uploaded to the monitoring platform.

[0016] Compared with the prior art, the beneficial effects of the present invention are as follows: The non-contact online algae detection system provided in the above technical solution involves the reflection and refraction of light emitted by the light source when it passes through a glass sheet. A reference photodetector is placed on the side of the glass sheet where the light is reflected. The reference photodetector can monitor changes in the emitted light and correct the influence of light source attenuation on the measurement results. The refracted light can be focused on the lower side of the liquid surface through the emitting lens. The algae are stimulated to produce fluorescence, and the fluorescence is then focused onto the receiving detector through the receiving lens. The receiving detector measures the fluorescence intensity, thereby achieving non-contact algae detection, avoiding system contamination by water samples, and maintaining the long-term cleanliness and stability of the system. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the non-contact online algae detection system provided in an embodiment of the present invention; Figure 2 A schematic diagram of a light source emitting assembly provided in an embodiment of the present invention; Figure 3 A schematic diagram of a fluorescence detection component provided in an embodiment of the present invention; Figure 4 This is a schematic diagram of the detection beam of the non-contact online algae detection system provided in an embodiment of the present invention; Figure 5 This is a schematic diagram of the measurement structure described in this invention; Figure 6 This is a circuit block diagram illustrating the execution of the detection method described in this invention.

[0018] 1. Housing; 2. Measuring cylinder; 21. Measuring opening; 22. Cylinder body; 23. Overflow cylinder; 24. Overflow cavity; 3. Light source emitting assembly; 31. Light source driver board; 32. Light source; 33. Reference photodetector; 34. Glass sheet; 35. Emitting lens; 36. Emitting aperture; 37. Emitting quartz glass sheet; 38. Emitting heating element; 39. Emitting sealing ring; 4. Fluorescence detection assembly; 41. Receiving circuit board; 42. Receiving detector; 43. Receiving aperture; 44. Receiving lens; 45. Filter; 46. Receiving quartz glass sheet; 47. Receiving heating element; 48. Receiving sealing ring; 51. Water inlet pipe; 52. Sludge discharge pipe; 53. Overflow pipe; 6. Display. Detailed Implementation

[0019] The present invention will now be described in more detail with reference to the accompanying drawings. It should be noted that the following description of the present invention with reference to the accompanying drawings is merely illustrative and not restrictive. Various different embodiments can be combined with each other to form other embodiments not shown in the following description.

[0020] Please see Figures 1 to 4 The present invention provides a non-contact online algae detection system, comprising a shell 1, a measuring cylinder 2, a light source emitting component 3, a fluorescence detection component 4, a water inlet pipe 51, a sludge discharge pipe 52, an overflow pipe 53, and a display 6.

[0021] The interior of housing 1 is hollow, and measuring cylinder 2, light source emitting component 3, and fluorescence detection component 4 are all fixedly installed inside housing 1.

[0022] Specifically, the measuring cylinder 2 is inclinedly disposed inside the housing 1. The measuring cylinder 2 includes a measuring opening 21, a cylinder 22, an overflow cylinder 23, and an overflow cavity 24. The cylinder 22 is hollow inside, and the middle part of the cylinder 22 is connected to the water inlet pipe 51. The water of the test piece can enter the cylinder 22 through the water inlet pipe 51. The top of the cylinder 22 is the measuring opening 21. As the water continues to increase, the water can rise to the measuring opening 21.

[0023] To facilitate water discharge, an overflow cylinder 23 is fitted on the outside of the cylinder 22, and an overflow cavity 24 is formed between the overflow cylinder 23 and the cylinder 22. Therefore, when there is too much water, the water can overflow from the measuring opening 21 into the overflow cavity 24. The overflow cavity 24 can be connected to the overflow pipe 53, thereby realizing the discharge of water.

[0024] In addition, the water may contain some impurities, which will gradually settle to the bottom of the cylinder 22. Therefore, to facilitate the cleaning of impurities, the bottom of the cylinder 22 can be connected to the sludge discharge pipe 52, which can then discharge the impurities from the bottom of the cylinder 22. This three-way water pipe design maintains the stability and cleanability of the measuring water path, ensuring that the measurement results are not affected by surface contamination of the measuring cylinder 2 during the cleaning cycle.

[0025] The light source emitting component 3 and the fluorescence detection component 4 are located on the upper side of the measuring cylinder 2. Importantly, the light source emitting component 3 and the fluorescence detection component 4 do not come into direct contact with the water body, thus avoiding contamination of the optical surface by water microorganisms. This maintains long-term measurement accuracy, reduces maintenance, and achieves non-contact algae detection.

[0026] Please see Figure 4 The dashed lines in the figure represent the emission optical axis of the light source emitting component 3 and the receiving optical axis of the fluorescence detection component 4, respectively. The emission optical axis of the light source emitting component 3 and the receiving optical axis of the fluorescence detection component 4 are set at 90° perpendicularly and intersect below the water surface of the measuring opening 21.

[0027] The light source emitting assembly 3 includes a light source driver board 31, a light source 32, a reference photodetector 33, a glass sheet 34, an emitting lens 35, an emitting aperture 36, an emitting quartz glass sheet 37, an emitting heating sheet 38, and an emitting sealing ring 39.

[0028] At least one light source 32 is provided, preferably two, symmetrically arranged on the light source driving plate 31. The light source driving plate 31 can control the opening and closing of the light sources 32, and the light sources 32 can generate pulsed light. The optical axes of both light sources 32 are parallel to the emission optical axis of the light source emitting assembly 3. A glass sheet 34 is provided in the emission optical path, and the angle between the glass sheet 34 and the emission optical axis of the light source emitting assembly 3 is 45°. A reference photodetector 33 is provided on the side of the glass sheet 34 reflecting light. The reference photodetector 33 can monitor the changes in the emitted light and correct the influence of the attenuation of the light source 32 on the measurement results. An emission aperture 36 is provided between the glass sheet 34 and the light source 32. The emission aperture 36 can limit the beam angle of the emitted light. Each light source 32 is provided with an emission aperture 36. An emission lens 35 is also provided in the emission optical path, which focuses the beam of light from the light source 32 onto the water surface of the measurement opening 21.

[0029] Furthermore, all components of the light source emitting assembly 3 can be housed within a single housing. The opening of the housing can be waterproofed using an emitting quartz glass plate 37. An emitting sealing ring 39 can be fixed to the emitting quartz glass plate 37 and can seal against the housing, achieving a waterproof rating of IP68. An emitting heating plate 38 is also fixed to the inner surface of the emitting quartz glass plate 37, which can remove water mist from the emitting quartz glass plate 37.

[0030] The fluorescence detection assembly 4 includes a receiving circuit board 41, a receiving detector 42, a receiving aperture 43, a receiving lens 44, a filter 45, a receiving quartz glass plate 46, a receiving heating plate 47, and a receiving sealing ring 48.

[0031] The receiving circuit board 41 is electrically connected to the receiving detector 42. A filter 45, a receiving aperture 43, a receiving lens 44, a receiving quartz glass plate 46, a receiving heating element 47, and a receiving sealing ring 48 are sequentially arranged in the receiving optical path. Specifically, the filter 45 can be a red cutoff filter, which can reduce the influence of external light and excitation light. The receiving aperture 43 restricts the received beam, ensuring that the light emitted by the light source 32 cannot enter the receiving detector 42 after reflection from the water surface. The algal fluorescence excited by the emitted light below the water surface is imaged onto the receiving detector 42 through the receiving lens 44.

[0032] In addition, all components of the fluorescence detection assembly 4 can be housed within a single housing. The opening of the housing can be waterproofed using a receiving quartz glass plate 46. A receiving sealing ring 48 can be fixed to the receiving quartz glass plate 46, and the receiving sealing ring 48 can seal against the housing, achieving a waterproof rating of IP68. A receiving heating element 47 is also fixedly mounted on the inner side of the receiving quartz glass plate 46, which can remove water mist from the receiving quartz glass plate 46.

[0033] It's important to understand that non-contact online algae detection systems primarily utilize the characteristic of algae having absorption and emission peaks in their spectrum. They emit monochromatic light of a specific wavelength into the water, where the algae absorb the energy of this monochromatic light and release monochromatic light of another wavelength. The intensity of the emitted light is directly proportional to the algae concentration in the water. For example, if 470nm and 610nm are used as excitation sources for chlorophyll A and cyanobacteria, respectively, the algae concentration can be determined by measuring the fluorescence intensity at a wavelength of 685nm produced by stimulated emission. This is because, under constant excitation light intensity, the fluorescence intensity has the following linear relationship with the algae concentration: Chl=a×V R +b(1) Chl represents algal concentration, V R is the voltage value output by the fluorescence detector and processed; a and b are the slope and intercept, respectively.

[0034] The voltage V of the standard solution was obtained by testing with a known concentration of algal standard solution Chl. R标 Substituting into equation (1), we get Chl 标 =a×V R标 +b. Using a blank reference, i.e., a standard solution with a concentration of 0, substituting into equation (1), we obtain Chl0 = a × V R0+b, the slope a and intercept b can be calculated from these two formulas, and can be obtained from formula (1) when measuring the actual algae concentration in water.

[0035] The non-contact online algae detection system uses LED or laser light sources with two wavelengths of 470nm and 610nm as light sources 32. The light source 32 is projected onto the water surface through the emitting lens 35 and converges into a test point underwater. When the water contains chlorophyll A or cyanobacteria, chlorophyll A or cyanobacteria are stimulated to produce fluorescence. The generated fluorescence is then converged onto the receiving detector 42 through the receiving lens 44. The receiving detector measures the fluorescence intensity and then displays the corresponding information on the display 6.

[0036] Based on the main composition of algae in the water, the types of light sources 2 can be increased to enhance the online detection of different algae. Additionally, when using an infrared LED light source, the beam emitted by the infrared LED encounters particulate matter in the water, producing scattered light. This scattered light can pass through a red cutoff filter, and the receiving detector 42 can measure the turbidity of the water body based on the received scattered light information. Turbidity is not only an important indicator of water quality, but the turbidity measurement results can also be used to make necessary corrections to the algae measurement results.

[0037] Furthermore, the non-contact online algae detection system provided by this invention, after entering a stable operating state, can perform multi-wavelength rotational measurements on various types of algae, and the cycle for detecting the concentration index of one type of algae is approximately 2 seconds, with a total of six wavelengths being measured in rotation. The information update time on the display 6 can be adjusted according to actual needs; for example, the update time can be set to 15 seconds, 30 seconds, 1 minute, etc.

[0038] In summary, the non-contact online algae detection system provided by this invention has the following advantages: (1) The light source emitting component 3 and the fluorescence detection component 4 are located above the water body being tested and do not come into contact with the flowing water sample, so as to avoid the optical system being contaminated by the water sample and to maintain the long-term cleanliness and stability of the optical system.

[0039] (2) The LED multispectral array time-division excitation light source adopts a converging optical system, which converges different LED excitation beams to the same underwater measurement position. One optical receiving device can receive different algal fluorescence, realizing the reuse of the optical system. The simplified optical system structure enables the measurement of the total number of algae such as chlorophyll A, cyanobacteria, and diatoms, as well as the measurement of different algae.

[0040] (3) Dual-path detection system, one path detects the excitation source and the other path detects the fluorescence source. It automatically monitors the attenuation of the excitation source and automatically compensates for the measurement results to maintain the long-term stability of the measurement results.

[0041] (4) The self-cleaning measuring cylinder 2 has one water inlet, one water overflow, and one mud and water discharge, maintaining the stability and cleanability of the measuring water path. During the cleaning cycle, it ensures that the measurement results are not affected by the surface contamination of the measuring cylinder 2. It can be installed in different application scenarios to realize the measurement of algae.

[0042] Non-contact online algae detection systems can simultaneously measure chlorophyll A, cyanobacteria, diatoms, etc., without contacting water samples, maintaining long-term accuracy, stability, and reliability of measurement results. The instruments require minimal maintenance, are easy to use, have low production costs, and offer excellent performance.

[0043] Please see Figures 5 to 6 According to one embodiment of the present invention, a non-contact online algae detection method, employing the non-contact online algae detection system described in any one of the above-mentioned methods, includes the following steps: S1. Conduct a survey of monitoring points in the target water area, and generate point deployment planning data based on the hydrological conditions of the water area and potential algal bloom areas; install a non-contact online algal detection system according to the deployment planning data, adjust the tilt angle of the measuring tube inside the shell so that the measuring opening is horizontally attached to the liquid surface, start the water inlet, overflow and sludge discharge circuit of the measuring tube to build a self-cleaning measuring water path, and simultaneously complete the position calibration of the light source emitting component and the fluorescence detection component (ensure that the emitting optical axis is perpendicular to the receiving optical axis and the intersection point is located below the liquid surface), and generate system deployment parameter data and steady-state data of the measuring water path. S2. Based on the system deployment parameter data and the steady-state data of the water circuit, the light source driver board is activated to drive and control the symmetrically set dual light sources, generating multi-wavelength modulated pulse excitation light such as 370nm and 470nm; the beam diffusion angle is limited by the emission aperture, and after being refracted by the glass sheet, the beam is focused by the emission lens to the preset detection point below the liquid surface. At the same time, the 45° reflection characteristic of the glass sheet is used to collect the light source intensity reference signal through the reference photodetector. Combined with the water mist removal status of the emission heating plate, the light source excitation parameter data and emission stability monitoring data are generated. S3. Based on the excitation parameter data of the light source, the fluorescence signal generated by the algae at the detection point is focused by the receiving lens of the fluorescence detection component. After being filtered by the receiving aperture, it passes through the receiving quartz glass plate (the receiving heating plate removes surface water mist in real time) and the filter to filter out external stray light and excitation light interference. The receiving detector converts the fluorescence light signal into a weak electrical signal, which is transmitted to the receiving circuit board for first-stage filtering and amplification. Then, it is amplified by second-stage amplification to improve the signal-to-noise ratio and generate noise-reduced fluorescence electrical signal data. S4. Based on the transmission stability monitoring data and the noise reduction fluorescence electrical signal data, the effective signal matching the excitation light is extracted and modulated by the synchronous demodulation module of the receiving circuit board. The analog signal is converted into a digital signal by the analog-to-digital conversion module. The preset algae concentration calibration formula (Chl=a×VR+b) is called, and the measurement results are automatically compensated by combining the light source attenuation data monitored by the reference photodetector. The concentration values ​​of chlorophyll A and various types of algae such as blue-green algae, green algae, and diatoms are calculated respectively to generate multi-dimensional algae concentration preliminary measurement data. S5. Verify the self-cleaning effectiveness of the measuring cylinder based on the steady-state data of the water path, and eliminate measurement deviations caused by water path pollution; calculate turbidity data by collecting water body scattered light signals through infrared light source, and perform turbidity compensation correction on the initial measurement data of multi-dimensional algae concentration; combine historical monitoring data to perform time-series trend analysis, determine the algae proliferation rate and outbreak risk level, and generate final algae concentration detection data, classification ratio data and water quality safety early warning data.

[0044] The working principle and effects of the above technical solution are as follows: The non-contact design combined with a self-cleaning measuring cylinder avoids pollution problems caused by direct contact between the detector and the water body, reducing the workload of frequent maintenance; the dual-optical-path automatic compensation and turbidity correction mechanism significantly improves the accuracy of algae concentration detection, enhances long-term data stability, and eliminates the need for subsequent secondary calibration; the multispectral excitation technology can simultaneously detect multiple algae and chlorophyll A, while also taking into account water turbidity indicators, making the detection dimensions more comprehensive; real-time online monitoring can promptly capture algae proliferation trends, avoiding water quality safety incidents caused by monitoring delays, ensuring water supply safety and ecological stability, reducing the labor intensity of manual sampling, avoiding the safety risks of field operations, and making algae monitoring more efficient and worry-free.

[0045] In one embodiment of the present invention, S1 includes: Based on hydrological data of the water area (including flow velocity, water depth, nitrogen and phosphorus content distribution, etc.) and distribution maps of potential algal bloom areas, and combined with the application scenarios of the detection system (such as reservoirs, water sources of water plants, etc.), differentiated point deployment plans are formulated, and point deployment planning data is generated; based on the point deployment planning data, the fixed installation of the non-contact online algal detection system is completed (such as wall mounting on the base, buoy deployment, or unmanned vessel mounting), and the tilt angle of the measuring cylinder inside the shell is adjusted to ensure that the measuring opening is horizontally in contact with the liquid surface; The water inlet circuit, overflow circuit, and sludge discharge circuit of the measuring cylinder are activated to construct a dynamic self-cleaning measuring water circuit. The water flow and stability of the water circuit are monitored in real time, and the initial data of the water circuit operation are generated. Simultaneously, the position of the light source emitting component and the fluorescence detection component are calibrated. Laser positioning technology is used to ensure that the emitting optical axis is perpendicular to the receiving optical axis and that the intersection point falls precisely in the preset detection area below the liquid surface. The calibration parameters are recorded. The system integrates installation parameters, calibration parameters, and initial water circuit operation data to generate system deployment parameter data; and continuously monitors the operation status of the self-cleaning measurement water circuit. After the flow rate and liquid level stabilize, it generates steady-state data of the measurement water circuit.

[0046] The working principle and effects of the above technical solution are as follows: Differentiated point deployment fits the hydrological characteristics of the water area and the application scenario, improving the accuracy of monitoring point setting and avoiding monitoring blind spots or invalid data caused by blind installation; multiple installation methods flexibly adapt to different scenarios such as reservoirs and water sources, enabling both long-term monitoring of fixed points and flexible mobile monitoring needs, without the need for additional modifications to the surrounding environment; self-cleaning water channels maintain stable flow and liquid level in real time, reducing the adhesion of algae and impurities in the measuring tube and avoiding the impact of water channel pollution on subsequent detection accuracy; laser positioning calibration ensures that the optical axis is vertical and the intersection point is accurately located, improving the accuracy of component installation and enhancing the stability of the system's initial operation; integrating the generated deployment parameters and water channel steady-state data lays a solid foundation for subsequent detection steps, avoiding cascading errors caused by initial setting deviations, and making the starting point of the entire detection process more reliable.

[0047] In one embodiment of the present invention, S2 includes: The microcontroller outputs a PWM modulation signal to drive the light source to generate multi-wavelength (such as 370nm, 470nm, 525nm, etc.) modulated pulse excitation light, generating light source modulation control data; the emission aperture is used to precisely limit the beam spread angle of the multi-wavelength modulated pulse excitation light to avoid beam divergence and energy loss, generating collimated beam data. The collimated beam is refracted by a highly transparent glass sheet at a 45° angle to the emission optical axis and then transmitted to the emission lens. The emission lens converges the refracted multi-wavelength beam into a focused beam, which is then precisely projected onto a preset detection point below the liquid surface to generate focused excitation light data. Simultaneously, by utilizing the reflective properties of the glass sheet, part of the excitation light is reflected to the reference photodetector to collect the light source intensity reference signal and generate the original intensity data of the light source; the emitting heating plate is activated to monitor the surface temperature and water mist status of the emitting quartz glass sheet in real time and generate water mist removal status data. By integrating light source modulation control data, focused excitation light data, original light source intensity data, and water mist removal status data, light source excitation parameter data and emission stability monitoring data are generated.

[0048] The working principle and effects of the above technical solution are as follows: PWM modulation generates multi-wavelength pulsed excitation light, improving the excitation specificity for different algae such as cyanobacteria and green algae, allowing all types of algae to be precisely triggered to produce fluorescence reactions; the emission aperture precisely limits the beam diffusion angle, avoiding light energy dispersion and loss, and significantly improving light utilization; the highly transparent glass sheet achieves both beam refraction and transmission, and reflects and collects intensity reference signals, ensuring that the excitation light is precisely guided to the emission lens, and providing raw data for subsequent light source attenuation correction, achieving two goals at once; the emission lens focuses multi-wavelength beams onto the detection point below the liquid surface, enhancing local light intensity and improving fluorescence excitation efficiency; the reference photodetector captures the original intensity of the light source in real time, laying a solid foundation for subsequent measurement result compensation and enhancing long-term data stability; the emission heating plate removes water mist from the surface of the quartz glass plate in real time, avoiding signal distortion caused by water mist blocking light, reducing optical transmission errors, and ensuring greater stability of the light source emission stage, laying a good foundation for the accuracy of subsequent detection data.

[0049] In one embodiment of the present invention, S3 includes: The fluorescence signal at the detection point is precisely focused through the receiving lens of the fluorescence detection component to generate focused fluorescence signal data; the focused fluorescence signal is filtered by the receiving aperture to remove stray light from non-target angles and generate directional fluorescence signal data. The directional fluorescence signal passes sequentially through the receiving quartz glass plate (the receiving heating plate works in real time to remove surface water mist and ensure light transmission) and the red cutoff filter to further filter out interference signals, including external natural light and excitation light, to generate pure fluorescence signal data. The receiving detector converts pure fluorescence signal data into a weak electrical signal to generate raw fluorescence electrical signal data; the raw fluorescence electrical signal data is then transmitted to the receiving circuit board, where high-frequency noise is removed and the signal strength is enhanced by a first-stage filter and amplification circuit to generate a first-stage amplified fluorescence electrical signal data. The amplified fluorescence electrical signal data is processed by a two-stage amplification circuit to improve the signal-to-noise ratio and generate noise-reduced fluorescence electrical signal data.

[0050] The working principle and effects of the above technical solution are as follows: The receiving lens precisely focuses the fluorescence signal at the detection point, improving signal concentration and enhancing the detectability of weak fluorescence; the receiving aperture filters out stray light from non-target angles, reducing interference from irrelevant light and preventing stray light from entering and damaging signal purity; the receiving heating plate removes water mist from the surface of the quartz glass plate in real time, ensuring light transmission and avoiding signal attenuation caused by water mist, thus reducing optical transmission errors; the red cutoff filter effectively isolates external natural light and excitation light, generating pure fluorescence signals, significantly improving signal purity and avoiding data distortion caused by interference signals; after the receiving detector converts the optical signal into an electrical signal, the two-stage amplification process not only enhances the intensity of weak signals but also significantly improves the signal-to-noise ratio, reducing the impact of noise on the measurement results; the entire process purifies and strengthens effective information layer by layer, laying a solid foundation for subsequent data analysis, avoiding deviations in algae concentration calculations due to signal problems, and making the detection data more accurate and reliable.

[0051] In one embodiment of the present invention, step S4 includes: Based on the PWM waveform parameters in the light source modulation control data, the noise-reduced fluorescent electrical signal data is synchronously demodulated, and an effective electrical signal matching the frequency of the modulated excitation light is extracted to generate synchronous effective electrical signal data. The analog-to-digital converter module converts the synchronous effective electrical signal data from analog to digital, generating fluorescent digital signal data; the reference detector, following the same processing procedure, converts the original intensity data of the light source into digital intensity data of the light source, generating emission light source attenuation monitoring data. Call the preset algae concentration calibration formula: Chl=a×VR+b, input the voltage value VR corresponding to the fluorescence digital signal data, and combine it with the slope a and intercept b previously calibrated by standard algae solution to preliminarily calculate the algae concentration value; Based on the monitoring data of emitted light source attenuation, the preliminary calculated algae concentration value is automatically compensated and corrected to eliminate the measurement error caused by light source attenuation; the concentration values ​​of various types of algae, including chlorophyll A algae, cyanobacteria, green algae, diatoms, dinoflagellates, and cryptophytes, are calculated separately to generate multi-dimensional preliminary algae concentration data.

[0052] The working principle and effects of the above technical solution are as follows: Synchronous demodulation based on PWM waveform parameters can accurately screen out effective signals that match the excitation light frequency, avoiding signal distortion caused by noise interference and improving the purity of the electrical signal; Analog-to-digital conversion converts analog signals into digital signals, enhancing the accuracy of data processing and reducing loss errors in signal transmission; The reference detector synchronously captures light source attenuation data and automatically compensates and corrects the initially calculated concentration value, effectively avoiding measurement deviations caused by light source aging, allowing the instrument to maintain long-term stability without secondary calibration; The preset calibration formula combined with the parameters calibrated by standard algal solution significantly improves the accuracy of concentration calculation, enabling accurate measurement of chlorophyll A content and simultaneous differentiation of various algae such as cyanobacteria and green algae, making the detection dimensions more comprehensive; The entire process requires no manual intervention or correction, reducing operational difficulty, avoiding human calculation errors, and making the initial measurement data of multi-dimensional algal concentration more valuable for reference.

[0053] In one embodiment of the present invention, step S5 includes: The relevant parameters, including influent flow rate, overflow velocity, and sludge discharge efficiency, are analyzed to determine whether there is any residual contamination on the inner wall of the measuring cylinder and the measuring opening, and to generate self-cleaning effectiveness verification data. If the verification data shows a risk of contamination, initiate an emergency cleaning procedure to eliminate measurement deviations caused by water contamination; if the verification is successful, retain the initial multi-dimensional algae concentration data. The infrared LED light source is activated to emit infrared light into the detection area, and the scattered light signal generated by particulate matter in the water is received to generate scattered light detection data; the turbidity value of the water is calculated based on the scattered light detection data to generate water turbidity correction parameters. The initial multi-dimensional algae concentration data is corrected using water turbidity correction parameters to improve measurement accuracy and generate corrected algae concentration data. Historical monitoring data stored in the system's built-in memory is retrieved to perform time-series trend analysis on the corrected algae concentration data and calculate the algae proliferation rate and slope of change. By combining algal proliferation rate, the proportion of various algal species, and water quality safety threshold, the risk level of algal outbreak (low, medium, high) is determined. The final algal concentration detection data, the proportion of various algal species, and the risk level determination results are integrated and corrected to generate algal concentration detection data, classification proportion data, and water quality safety early warning data, which are then uploaded to the monitoring platform via a 4G module or RS485 communication interface.

[0054] The working principle and effects of the above technical solution are as follows: By analyzing the influent flow rate, overflow velocity, and sludge discharge efficiency, the self-cleaning effect is verified, and residual pollution in the measuring tube can be detected in a timely manner. An emergency cleaning procedure can be initiated to avoid detection deviations caused by water pollution, making the data foundation more reliable. Infrared light source collects scattered light from the water body to calculate turbidity. Correction parameters are used to recalibrate the initial measurement data, which greatly improves the accuracy of algae concentration measurement and reduces errors caused by environmental interference. Historical data is retrieved for time-series trend analysis to accurately calculate the algae proliferation rate. Combined with the classification ratio and safety threshold, the risk level is determined to avoid water quality safety incidents caused by untimely algae outbreak warnings. Finally, the data is uploaded to the monitoring platform via 4G or RS485, which not only allows staff to keep abreast of water quality dynamics in real time, but also provides a scientific basis for the formulation of prevention and control measures, enhances the initiative of water quality management, and makes water supply safety and ecological stability more guaranteed.

[0055] The above embodiments are merely preferred embodiments of the present invention and should not be construed as limiting the scope of protection of the present invention. Any non-substantial changes and substitutions made by those skilled in the art based on the present invention shall fall within the scope of protection claimed by the present invention.

Claims

1. A non-contact online algae detection system, characterized in that, include: Shell (1); The measuring cylinder (2) is inclinedly disposed inside the housing (1), and the measuring cylinder (2) has a horizontally disposed measuring opening (21). The light source emitting assembly (3), located on the upper side of the measurement opening (21), includes a light source driving plate (31), a light source (32), a reference photodetector (33), a glass sheet (34), and an emitting lens (35). The light source driving plate (31) is electrically connected to the light source (32). The glass sheet (34) is set at a 45° angle with the emitting optical axis of the light source emitting assembly (3). The reference photodetector (33) is set on the side of the glass sheet (34) that reflects light. The emitting lens (35) is set on the side of the glass sheet (34) that refracts light. The focal point of the light beam of the light source (32) converged by the emitting lens (35) is located below the liquid surface of the measurement opening (21). The fluorescence detection component (4) is located on the upper side of the measurement opening (21) and includes a receiving circuit board (41), a receiving detector (42), a receiving aperture (43), and a receiving lens (44). The receiving circuit board (41) is electrically connected to the receiving detector (42). The receiving aperture (43) and the receiving lens (44) are sequentially arranged on the side of the receiving detector (42) near the measurement opening (21). The emission optical axis of the light source emitting component (3) is perpendicular to the receiving optical axis of the fluorescence detection component (4), and the intersection point is located below the liquid surface of the measurement opening (21).

2. The non-contact online algae detection system as described in claim 1, characterized in that, The light source emitting assembly (3) further includes an emitting aperture (36), an emitting quartz glass plate (37), and an emitting heating plate (38). The emitting aperture (36) is disposed between the light source (32) and the glass plate (34). The emitting quartz glass plate (37) is disposed on the side of the emitting lens (35) facing the measuring opening (21). The emitting heating plate (38) is fixed to the emitting quartz glass plate (37).

3. The non-contact online algae detection system as described in claim 1, characterized in that, The fluorescence detection assembly (4) further includes a filter (45), a receiving quartz glass plate (46), and a receiving heating plate (47). The filter (45) is disposed between the receiving detector (42) and the receiving aperture (43). The receiving quartz glass plate (46) is disposed on the side of the receiving lens (44) facing the measuring opening (21). The receiving heating plate (47) is fixed to the receiving quartz glass plate (46). There are two light sources (32), which are symmetrically disposed on the light source driving plate (31).

4. The non-contact online algae detection system as described in claim 1, characterized in that, The measuring cylinder (2) includes a cylinder body (22) and an overflow cylinder (23). The measuring opening (21) is formed on the upper side of the cylinder body (22). The overflow cylinder (23) is sleeved outside the cylinder body (22), and an overflow cavity (24) is formed between the overflow cylinder (23) and the cylinder body (22).

5. A non-contact online algae detection method, characterized in that, The non-contact online algae detection system according to any one of claims 1-4 includes the following steps: S1. Explore the target water area and generate point deployment planning data. Based on this, install a non-contact online algae detection system, adjust the angle of the measuring tube to construct a self-cleaning measuring water path, complete component calibration, and generate system deployment parameter data and steady-state data of the measuring water path. S2. Based on system deployment and other data, dual light sources are driven to generate multi-wavelength modulated pulse excitation light, which is then processed and converged to the detection point. The reference signal is acquired using the characteristics of the glass sheet, and the light source excitation parameter data and emission stability monitoring data are generated in combination with the water mist removal status. S3. Based on the excitation parameter data of the light source, the fluorescence detection component gathers the fluorescence signal, which is then processed and converted into an electrical signal and amplified to generate noise-reduced fluorescence electrical signal data. S4. Extract effective signals based on data such as emission stability and convert them into digital signals. Use formulas to automatically compensate for light source attenuation data, calculate the concentration values ​​of various algae, and generate multi-dimensional preliminary algae concentration data. S5. Verify the self-cleaning effectiveness of the measuring tube, correct the initial algae concentration data in multiple dimensions through turbidity data, determine the algae proliferation and risk level by combining historical data, and generate the final algae concentration detection data, classification ratio data and water quality safety early warning data.

6. The non-contact online algae detection method as described in claim 5, characterized in that, S1 includes: Based on the hydrological characteristics of the water area and the distribution map of potential algal bloom areas, and combined with the application scenarios of the detection system, a differentiated deployment plan for the monitoring points is formulated, and the deployment planning data for the monitoring points is generated; based on the deployment planning data for the monitoring points, the fixed installation of the non-contact online algal detection system is completed. The water inlet circuit, overflow circuit, and sludge discharge circuit of the measuring cylinder are activated to construct a dynamic self-cleaning measuring water circuit. The water flow and stability of the water circuit are monitored in real time, and the initial data of the water circuit operation are generated. Simultaneously, the position of the light source emitting component and the fluorescence detection component are calibrated. Laser positioning technology is used to ensure that the emitting optical axis is perpendicular to the receiving optical axis and that the intersection point falls precisely in the preset detection area below the liquid surface. The calibration parameters are recorded. The system integrates installation parameters, calibration parameters, and initial water circuit operation data to generate system deployment parameter data; and continuously monitors the operation status of the self-cleaning measurement water circuit. After the flow rate and liquid level stabilize, it generates steady-state data of the measurement water circuit.

7. The non-contact online algae detection method as described in claim 5, characterized in that, The S2 includes: The microcontroller outputs a PWM modulation signal to drive the light source to generate multi-wavelength modulated pulse excitation light, generating light source modulation control data; the emission aperture is used to precisely limit the beam spread angle of the multi-wavelength modulated pulse excitation light, generating collimated beam data. The collimated beam is refracted by a highly transparent glass sheet at a 45° angle to the emission optical axis and then transmitted to the emission lens. The emission lens converges the refracted multi-wavelength beam into a focused beam and projects it onto a preset detection point below the liquid surface to generate focused excitation light data. Simultaneously, by utilizing the reflective properties of the glass sheet, part of the excitation light is reflected to the reference photodetector to collect the light source intensity reference signal and generate the original intensity data of the light source; the emitting heating plate is activated to monitor the surface temperature and water mist status of the emitting quartz glass sheet in real time and generate water mist removal status data. By integrating light source modulation control data, focused excitation light data, original light source intensity data, and water mist removal status data, light source excitation parameter data and emission stability monitoring data are generated.

8. The non-contact online algae detection method as described in claim 5, characterized in that, The S3 includes: The fluorescence signal at the detection point is precisely focused through the receiving lens of the fluorescence detection component to generate focused fluorescence signal data; the focused fluorescence signal is filtered by the receiving aperture to remove stray light from non-target angles and generate directional fluorescence signal data. The directional fluorescence signal passes through the receiving quartz glass plate and the red cutoff filter in sequence to further filter out interference signals and generate pure fluorescence signal data; The receiving detector converts pure fluorescence signal data into a weak electrical signal to generate raw fluorescence electrical signal data; the raw fluorescence electrical signal data is then transmitted to the receiving circuit board, where high-frequency noise is removed and the signal strength is enhanced by a first-stage filter and amplification circuit to generate a first-stage amplified fluorescence electrical signal data. The amplified fluorescence electrical signal data is processed by a two-stage amplification circuit to generate noise-reduced fluorescence electrical signal data.

9. The non-contact online algae detection method as described in claim 5, characterized in that, The S4 includes: Based on the PWM waveform parameters in the light source modulation control data, the noise-reduced fluorescent electrical signal data is synchronously demodulated, and an effective electrical signal matching the frequency of the modulated excitation light is extracted to generate synchronous effective electrical signal data. The analog-to-digital converter module converts the synchronous effective electrical signal data from analog to digital, generating fluorescent digital signal data; the reference detector, following the same processing procedure, converts the original intensity data of the light source into digital intensity data of the light source, generating emission light source attenuation monitoring data. Call the preset algae concentration calibration formula: Chl=a×VR+b, input the voltage value VR corresponding to the fluorescence digital signal data, and combine it with the slope a and intercept b previously calibrated by standard algae solution to preliminarily calculate the algae concentration value; Based on the attenuation monitoring data of the emitted light source, the initially calculated algae concentration value is automatically compensated and corrected, and the concentration values ​​of various types of algae are calculated separately to generate multi-dimensional preliminary algae concentration data.

10. The non-contact online algae detection method as described in claim 5, characterized in that, The S5 includes: Analyze relevant parameters to determine whether there is any contamination residue on the inner wall of the measuring cylinder and the measuring opening, and generate self-cleaning effectiveness verification data; If the verification data shows a risk of contamination, initiate an emergency cleaning procedure to eliminate measurement deviations caused by water contamination; if the verification is successful, retain the initial multi-dimensional algae concentration data. The infrared LED light source is activated to emit infrared light into the detection area, and the scattered light signal generated by particulate matter in the water is received to generate scattered light detection data; the turbidity value of the water is calculated based on the scattered light detection data to generate water turbidity correction parameters. The initial multidimensional algae concentration data is corrected using water turbidity correction parameters to generate corrected algae concentration data. Historical monitoring data stored in the system's built-in memory is retrieved to perform time-series trend analysis on the corrected algae concentration data and calculate the algae proliferation rate and slope of change. By combining algal proliferation rate, the proportion of various algal species, and water quality safety threshold, the risk level of algal outbreak is determined; the final algal concentration detection data, classification proportion data, and water quality safety early warning data are generated by integrating and correcting algal concentration data, algal species classification proportion data, and risk level determination results, and then uploaded to the monitoring platform.

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