A milk multi-component online analysis device

Abstract

This invention discloses an online multi-component analysis device for milk, comprising a housing and a milk sample container, a filter switching mechanism, a detection execution mechanism, and a supplementary lighting mechanism disposed within the housing. The filter switching mechanism includes a filter turntable and a rotation drive mechanism for driving the turntable to rotate. The turntable has multiple filter mounting holes, with different filters installed in different holes. The detection execution mechanism includes a photoelectric detection module and a detection drive mechanism for driving the photoelectric detection module to move spatially. In operation, the photoelectric detection module detects the milk sample in the milk sample container through the filters on the turntable. The supplementary lighting mechanism includes a light source module and a cylindrical light shield. The light source module is located inside the cylindrical light shield, which has light-transmitting holes. This device enables high-precision, rapid, and convenient multi-component detection of milk.

Description

Technical Field

[0001] This invention relates to food testing devices, specifically to an online multi-component analysis device for milk. Background Technology

[0002] Fat, protein, and lactose content are core indicators for measuring the nutritional value and quality of milk. Therefore, rapid and accurate detection of these three components is crucial for dairy product quality control. With the continued growth of the dairy market, according to the "China Dairy Industry Blue Book," the retail sales of China's dairy products market reached approximately RMB 471.4 billion in 2021 and are projected to reach approximately RMB 596.7 billion by 2026, representing a compound annual growth rate of 4.8%. Meanwhile, the global dairy processing equipment market was valued at US$12.6 billion in 2023 and is projected to continue expanding at an average annual growth rate exceeding 4.9% between 2024 and 2032. This indicates a growing demand in the dairy industry for rapid, accurate, and efficient detection of milk components, driving the continuous development of the testing technology and equipment market.

[0003] Currently, traditional methods for milk component detection mainly include Soxhlet extraction, Kjeldahl ammonia determination, and high-performance liquid chromatography (HPLC). While these methods offer high accuracy, they generally suffer from long detection times, require laboratory operation, and are complex, making them unsuitable for the rapid detection needs in dairy production. In recent years, some ultrasonic testing equipment and automated chemical detection methods have shortened detection time and reduced environmental pollution to some extent; however, their accuracy is easily affected by temperature, impurities, and sample condition, and their anti-interference capabilities are insufficient. Mid-infrared spectroscopy, although capable of high-precision quantitative analysis, typically requires sophisticated sample preparation, is suitable for single-sample detection, and suffers from high equipment costs and complex maintenance, hindering its widespread adoption in field and distributed applications.

[0004] In contrast, near-infrared spectroscopy (NIRS) has gradually become a research hotspot for multi-component detection in milk due to its rapid, non-destructive, and high-precision characteristics. Existing research shows that integrating NIRS into automated milking or production line equipment can achieve periodic and continuous monitoring of fat, protein, lactose, and somatic cell counts in milk, significantly improving detection efficiency. However, these devices are often highly integrated, expensive, and have strict requirements for sample flow and environmental conditions, making them difficult to promote in small and medium-sized dairy processing plants or for rapid on-site detection. While some portable NIRS devices have achieved good results in classification and identification, they are usually limited to qualitative analysis and lack the ability to simultaneously quantify protein, fat, and lactose. Their scalability and detection accuracy remain limited, making it difficult to meet the dairy industry's needs for simultaneous multi-indicator detection and precise quality control.

[0005] In summary, there is currently a lack of a milk component detection device that can achieve rapid, convenient, and simultaneous multi-component analysis while ensuring detection accuracy. Summary of the Invention

[0006] The purpose of this invention is to overcome the above-mentioned problems and provide an online multi-component analysis device for milk, which can perform multi-component detection of milk with high accuracy, speed and convenience.

[0007] The objective of this invention is achieved through the following technical solution: An online multi-component analysis device for milk includes a housing and a milk sample container, a filter switching mechanism, a detection and execution mechanism, and a supplementary lighting mechanism disposed within the housing. The milk sample container is used to hold the milk sample to be tested; The filter switching mechanism includes a filter turntable and a rotation drive mechanism for driving the filter turntable to rotate. The filter turntable is provided with multiple filter mounting holes, and different filter sheets are provided in different filter mounting holes. The detection actuator includes a photoelectric detection module and a detection drive mechanism for driving the photoelectric detection module to move in space. When the photoelectric detection module is in operation, it detects the milk sample in the milk sample container through the filter on the filter turntable. The supplementary lighting mechanism includes a light source module and a cylindrical light shield. The light source module is located inside the cylindrical light shield, and the cylindrical light shield has a light-transmitting hole. When the light source module is in operation, the light is projected onto the milk sample container through the light-transmitting hole.

[0008] In a preferred embodiment of the present invention, the milk sample container is connected to both a milk inlet pipe and a milk outlet pipe. This allows a small peristaltic pump to quantitatively deliver liquid milk into the milk sample container at a constant flow rate of 200 mL / min. The peristaltic pump employs a non-contact pressurized delivery method, with its internal rollers not directly contacting the liquid, effectively preventing sample contamination. The milk enters the milk sample container through the milk inlet pipe, and the fixed pipe and the milk sample container structure form a uniform liquid layer, ensuring stable milk flow within the measurement area without bubble interference. This improves the repeatability and reliability of spectral acquisition, enabling automated sample introduction and continuous detection.

[0009] In a preferred embodiment of the present invention, the rotary drive mechanism includes a rotary drive motor, the output shaft of which is connected to the filter turntable. This direct drive of the filter turntable by the rotary drive motor enables rapid and precise switching of the filter. This structure simplifies the transmission process, improves the stability and reliability of the system, and facilitates efficient acquisition of multi-band spectra during continuous detection.

[0010] Furthermore, the supplementary lighting mechanism also includes an optical magnification switching mechanism, which includes a switching mounting frame, optical lenses, and a magnification switching drive mechanism. The switching mounting frame is rotatably connected to the top of the housing via a rotating cylinder, and the switching mounting frame is provided with multiple lens mounting slots. The light source module is located inside the switching mounting frame. The optical lenses are provided with multiple lenses, each with an optical magnification corresponding to multiple filters. The multiple optical lenses are evenly arranged in a circular pattern around the axis of the rotating cylinder on the outside of the light source module.

[0011] Furthermore, the rate switching drive mechanism includes a rate switching drive motor and a rate switching transmission assembly. The rate switching drive motor is composed of the rotary drive motor. The rate switching transmission assembly includes a synchronous transmission assembly and a telescopic assembly. The synchronous transmission assembly includes a drive shaft, a drive disc, and a bevel gear assembly. The drive shaft includes a first drive shaft, a second drive shaft, and a third drive shaft. The drive disc includes a first drive disc and a second drive disc. The bevel gear assembly includes a first bevel gear and a second bevel gear. The telescopic assembly includes a telescopic mounting assembly and a telescopic transmission assembly. The telescopic mounting assembly includes a fixed mounting component and a telescopic mounting component. The telescopic transmission assembly includes a first telescopic transmission rod, an intermediate telescopic frame, and a second telescopic transmission rod. One end of the first drive shaft is fixedly connected to the center of the filter disc turntable, and the other end of the first drive shaft rotatably passes through the fixed mounting member and is coaxially fixedly connected to the first drive disk; one end of the second drive shaft is rotatably connected to one end of the telescopic mounting member, and the other end of the second drive shaft is coaxially connected to the first bevel gear and the second drive disk, which are fixedly connected; the third drive shaft is vertically arranged, one end of which is fixedly connected to the bottom of the switching mounting bracket, and the second bevel gear is rotatably connected to the third drive shaft, which passes through and is limited in position. The other end of the telescopic mounting component is telescopically connected to the fixed mounting component; one end of the first telescopic transmission rod is eccentrically connected to the first transmission disc via a universal joint structure, and the other end of the first telescopic transmission rod is telescopically connected to the intermediate telescopic frame; one end of the second telescopic transmission rod is eccentrically connected to the second transmission disc via a universal joint structure, and the other end of the second telescopic transmission rod is telescopically connected to the intermediate telescopic frame; both the first and second telescopic transmission rods are electromagnet structures, and the first telescopic transmission rod is in contact with the second telescopic transmission rod in the fully retracted state.

[0012] Through the above structure, on the one hand, the power of the rotary drive motor can be shared to synchronously complete the switching of optical lenses, so that the filter can be matched with the corresponding magnification optical lens to better match the absorption characteristics of different components in the near-infrared band, thereby achieving optimized optical irradiation and measurement of components such as fat, protein, and lactose, and improving detection accuracy. The specific operation is as follows: when it is necessary to switch the filter to detect milk samples, the rotary drive motor drives the filter turntable to rotate a certain angle, so that the desired filter rotates to the detection position; at the same time, the first drive shaft rotates synchronously with the filter turntable, driving the first drive disk to rotate, and then the first telescopic drive rod transmits the power to the second telescopic drive rod, which in turn drives the second drive disk to rotate. Finally, the first bevel gear and the second bevel gear change the direction to transmit the power to the switching mounting frame, thereby driving the corresponding optical lens to rotate to the inside of the light-transmitting hole of the cylindrical light shield, thus completing the switching of optical lenses. On the other hand, in practice, it is necessary to perform regular maintenance or replace different filters inside the device. Therefore, it is necessary to open the top cover of the housing. After the cover is opened, the light source module will be away from the cylindrical light shield. This solution can ensure that the transmission structure of the magnification switching drive mechanism is not interrupted. The telescopic mounting rod can extend relative to the fixed mounting part. At the same time, the first telescopic transmission rod and the second telescopic transmission rod can extend relative to the middle telescopic frame. With the top cover of the housing and the distance of the light source module, the first bevel gear and the second bevel gear can always maintain meshing, which facilitates the subsequent high-precision component detection work.

[0013] In summary, by sharing the power of a rotary drive motor to achieve synchronous switching between the filter and the optical lens, not only is the coordination and detection accuracy of the optical system improved, but the drive structure is also simplified, reducing the complexity and cost of the overall device. Furthermore, the telescopic transmission design ensures that the transmission chain remains connected when the cover is opened for maintenance or filter replacement, avoiding recalibration and improving the maintainability and long-term stability of the equipment.

[0014] In a preferred embodiment of the present invention, the photoelectric detection module is a high-sensitivity photoelectric detector used to detect the photoelectric signal of the milk sample and transmit the photoelectric signal to the I-V conversion module, which converts it into a voltage signal and amplifies it. The amplified voltage signal is transmitted to the data acquisition module, which converts it into a digital signal in real time. The data acquisition module sends the digital spectral data to a computer or embedded analysis module through a high-speed communication interface for model analysis of fat, protein and lactose content.

[0015] Furthermore, the photodetector is installed at the input end of the I–V conversion module. The spectral response range of the photodetector is 900–2100 nm, and the diameter of the photosensitive surface is 1000 μm, which can cover the main absorption range of milk fat, protein and lactose in the near-infrared region.

[0016] Furthermore, the data acquisition module is located inside the enclosure, which contains a relay and a power supply.

[0017] In a preferred embodiment of the present invention, the detection drive mechanism is a multi-axis robotic arm, and the photoelectric detection module is disposed at the end of the multi-axis robotic arm. Using a multi-axis robotic arm as the drive mechanism for the photoelectric detection module enables the detector to flexibly and accurately adjust its position and orientation in three-dimensional space. This design enhances the detection capability of different regions or different liquid layers within the sample container, facilitating the acquisition of more representative spectral data, and is particularly suitable for the detection of flowing or non-uniform samples.

[0018] In a preferred embodiment of the present invention, the light source module is a broadband near-infrared light source module. The light beam emitted by this module passes through a filter and illuminates the milk sample container at an incident angle of 45° ± 5°. This causes multiple scattering of the light within the milk to enhance the diffuse reflection component and suppress interference from specular reflection light on the detector signal.

[0019] Compared with the prior art, the present invention has the following advantages: 1. By integrating a filter switching mechanism, a detection execution mechanism, and a supplementary lighting mechanism, this invention enables rapid detection of milk samples without the need for complex sample pretreatment, achieving online, non-destructive, and simultaneous detection of fat, protein, and lactose, significantly improving the efficiency and convenience of on-site dairy product testing.

[0020] 2. The filter turntable of the present invention is equipped with multiple sets of different filters. Combined with a detector that can move in space, it can realize the simultaneous detection of multiple components such as fat, protein, and lactose in milk, which solves the limitation of existing portable devices that can only detect qualitative or single indicators.

[0021] 3. The supplementary lighting mechanism is equipped with a cylindrical light shield and a light-transmitting hole, which can effectively control the light source conditions, reduce ambient light interference, and improve the stability and accuracy of the detection signal, thereby ensuring high precision of the detection results.

[0022] 4. By adjusting the detector position and switching the filter using a robotic arm, the device's adaptability to changes in sample state is enhanced, the interference of factors such as temperature and flow state on the detection results is reduced, and the device's anti-interference and reliability are improved. Attached Figure Description

[0023] Figure 1This is a three-dimensional structural diagram of the online multi-component milk analysis device of the present invention in the closed state, with the top cover of the box hidden in the figure.

[0024] Figure 2 This is a three-dimensional structural diagram of the online multi-component milk analysis device of the present invention in the open state, with the main body of the box hidden in the figure.

[0025] Figure 3 This is a front view of the filter switching mechanism and the supplementary lighting mechanism of the present invention in the closed state.

[0026] Figure 4 This is a front view of the filter switching mechanism and the supplementary lighting mechanism of the present invention in the open state.

[0027] Figure 5 This is a three-dimensional structural diagram of the light source module, switching mounting bracket, and optical lens of the supplementary lighting mechanism of the present invention. Detailed Implementation

[0028] To enable those skilled in the art to fully understand the technical solutions of the present invention, the present invention will be further described below in conjunction with embodiments and accompanying drawings, but the embodiments of the present invention are not limited thereto.

[0029] Example 1 Combination Figures 1-2 The online multi-component milk analysis device of this embodiment includes a housing 1 and a milk sample container 2, a filter switching mechanism, a detection execution mechanism, and a supplementary lighting mechanism disposed within the housing 1. The housing 1 is 3D printed from black PLA, a material with excellent light absorption properties, and has overall dimensions of 10cm × 10cm × 10cm. This material effectively reduces interference from ambient light and improves the stability of spectral measurements.

[0030] Combination Figures 1-2 The milk sample container 2 is used to hold the milk sample to be tested; the milk sample container 2 is a fixed optical path structure, made of high-transmittance quartz glass, with an outer diameter of 8mm, an inner diameter of 6mm, a total length of 70mm, and an actual optical path thickness of 10mm.

[0031] Specifically, the milk sample container 2 is connected to both a milk inlet pipe and a milk outlet pipe. This allows a small peristaltic pump to quantitatively deliver liquid milk into the milk sample container 2 at a constant flow rate of 200 mL / min. The peristaltic pump employs a non-contact pressurized delivery method, ensuring that its internal rollers do not directly contact the liquid, effectively preventing sample contamination. The milk enters the milk sample container 2 through the milk inlet pipe, and the fixed pipe and the structure of the milk sample container 2 form a uniform liquid layer, thus ensuring stable milk flow within the measurement area without bubble interference. This improves the repeatability and reliability of spectral acquisition, enabling automated sample introduction and continuous detection.

[0032] Combination Figures 1-4 The filter switching mechanism includes a filter turntable 3 and a rotation drive mechanism for driving the filter turntable 3 to rotate. The filter turntable 3 is provided with multiple filter mounting holes 3-1, and different filter (not shown in the figure) are provided in different filter mounting holes 3-1, namely, a fat characteristic wavelength filter, a protein characteristic wavelength filter and a lactose characteristic wavelength filter; wherein, the center wavelengths of the filter are respectively: 1730nm fat characteristic absorption band, 1550nm protein characteristic absorption band and 1064nm lactose characteristic absorption band.

[0033] Combination Figures 1-4 The rotary drive mechanism includes a rotary drive motor 4, the output shaft of which is connected to the filter turntable 3. In this way, by directly driving the filter turntable 3 with the rotary drive motor 4, rapid and precise switching of the filter is achieved. This structure simplifies the transmission links, improves the stability and reliability of the system, and facilitates efficient acquisition of multi-band spectra during continuous detection.

[0034] Combination Figures 1-4 The detection actuator includes a photoelectric detection module 5 and a detection drive mechanism for driving the photoelectric detection module 5 to move in space. When the photoelectric detection module 5 is in operation, it detects the milk sample in the milk sample container 2 through the filter on the filter turntable 3. Combination Figures 1-4 The photoelectric detection module 5 is a high-sensitivity photoelectric detector used to detect the photoelectric signal of the milk sample and transmit the photoelectric signal to the I-V conversion module 6. The I-V conversion module 6 converts the signal into a voltage signal and amplifies it. The amplified voltage signal is transmitted to the data acquisition module 7 and converted into a digital signal in real time. The data acquisition module 7 sends the digital spectral data to a computer or embedded analysis module through a high-speed communication interface for model analysis of fat, protein and lactose content.

[0035] Furthermore, the photodetector is installed at the input end of the I–V conversion module 6. The spectral response range of the photodetector is 900–2100 nm, and the diameter of the photosensitive surface is 1000 μm, which can cover the main absorption range of milk fat, protein and lactose in the near-infrared region.

[0036] Furthermore, the enclosure 1 is equipped with a relay 8 and a power supply 9; the data acquisition module 7 is installed on the outside of the enclosure 1, with dimensions of 78mm×63mm×26.5mm, a sampling rate of up to 200kSPS, and supports synchronous sampling and real-time transmission. It is used to convert the voltage signal after I-V amplification into a digital signal and send it to the host computer for analysis.

[0037] Combination Figures 1-4 The detection drive mechanism is a multi-axis robotic arm 10, and the photoelectric detection module 5 is located at the end of the multi-axis robotic arm 10. Using the multi-axis robotic arm 10 as the drive mechanism for the photoelectric detection module 5 allows the detector to flexibly and accurately adjust its position and orientation in three-dimensional space. This design enhances the detection capability of different regions or different liquid layers within the sample container, facilitating the acquisition of more representative spectral data, and is particularly suitable for the detection of flowing or non-uniform samples.

[0038] Specifically, the top cover of the housing 1 is equipped with a microcontroller, which uses an STM32F103C8T6 chip. This microcontroller is responsible for controlling the on / off state of the halogen lamp and the rotation angle of the motor via relays, thereby automating the management of the light source and the switching of the filter. The photodetector, I-V module, motor and relay are all powered by a 5V power supply module.

[0039] During system operation, the microcontroller activates the light source according to the set detection procedure, controls the sequential switching of the filters, and simultaneously triggers the data acquisition card for synchronous acquisition. The acquired spectral electrical signals are digitally processed and transmitted to the host computer or embedded algorithm module, enabling rapid and non-destructive online detection of milk fat, protein, and lactose content.

[0040] Combination Figures 1-4 The supplementary lighting mechanism includes a light source module 11 and a cylindrical light shield 12. The light source module 11 is located inside the cylindrical light shield 12. The cylindrical light shield 12 is provided with a light-transmitting hole 12-1. When the light source module 11 is in working condition, the light passes through the light-transmitting hole 12-1 and is projected onto the milk sample container 2.

[0041] Combination Figures 1-4 The light source module 11 is a broadband near-infrared light source—a halogen tungsten lamp. The spectral range of this halogen tungsten lamp covers 900–2500 nm, meeting the requirements for near-infrared absorption detection of multiple components in milk. The light beam emitted from the halogen tungsten lamp passes through a filter and illuminates the milk sample container 2 at an incident angle of 45°±5°. This causes multiple scattering of light within the milk to enhance the diffuse reflection component and suppress interference from specular reflection light on the detector signal.

[0042] Combination Figures 1-5The supplementary lighting mechanism also includes an optical magnification switching mechanism, which includes a switching mounting frame 13, optical lenses 14, and a magnification switching drive mechanism. The switching mounting frame 13 is rotatably connected to the top of the housing 1 via a rotating cylinder 15. The switching mounting frame 13 is provided with multiple lens mounting slots. The light source module 11 is located inside the switching mounting frame 13. The optical lenses 14 are provided with multiple optical magnifications, each corresponding to a different filter, namely, fat optical magnification lens, protein optical magnification lens, and lactose optical magnification lens. The multiple optical lenses 14 are evenly arranged in a circular pattern around the axis of the rotating cylinder 15 on the outside of the light source module 11.

[0043] Combination Figures 1-4 The rate switching drive mechanism includes a rate switching drive motor and a rate switching transmission assembly. The rate switching drive motor is composed of the rotary drive motor 4. The rate switching transmission assembly includes a synchronous transmission assembly and a telescopic assembly. The synchronous transmission assembly includes a drive shaft, a drive disc, and a bevel gear assembly. The drive shaft includes a first drive shaft 16, a second drive shaft 17, and a third drive shaft 18. The drive disc includes a first drive disc 19 and a second drive disc 20. The bevel gear assembly includes a first bevel gear 21 and a second bevel gear 22. The telescopic assembly includes a telescopic mounting assembly and a telescopic transmission assembly. The telescopic mounting assembly includes a fixed mounting component 23 and a telescopic mounting component 24. The telescopic transmission assembly includes a first telescopic transmission rod 25, an intermediate telescopic frame 26, and a second telescopic transmission rod 27.

[0044] One end of the first drive shaft 16 is fixedly connected to the center of the filter turntable 3, and the other end of the first drive shaft 16 rotatably passes through the fixed mounting member 23 and is coaxially fixedly connected to the first drive disk 19; one end of the second drive shaft 17 is rotatably connected to one end of the telescopic mounting member 24, and the other end of the second drive shaft 17 is coaxially connected to the first bevel gear 21 and the second drive disk 20, and the first bevel gear 21 and the second drive disk 20 are fixedly connected; the third drive shaft 18 is vertically arranged, one end of the third drive shaft 18 is fixedly connected to the bottom of the switching mounting bracket 13, the second bevel gear 22 is rotatably connected to the third drive shaft 18, and the second drive shaft 17 passes through the third drive shaft 18 and achieves a limit position.

[0045] The other end of the telescopic mounting component 24 is telescopically connected to the fixed mounting component 23; one end of the first telescopic transmission rod 25 is eccentrically connected to the first transmission disk 19 through a universal joint structure, and the other end of the first telescopic transmission rod 25 is telescopically connected to the intermediate telescopic frame 26; one end of the second telescopic transmission rod 27 is eccentrically connected to the second transmission disk 20 through a universal joint structure, and the other end of the second telescopic transmission rod 27 is telescopically connected to the intermediate telescopic frame 26; both the first telescopic transmission rod 25 and the second telescopic transmission rod 27 are electromagnet structures, and the first telescopic transmission rod 25 is in contact with the second telescopic transmission rod 27 in the fully retracted state.

[0046] Through the above structure, on the one hand, the power of the rotary drive motor 4 can be shared to synchronously complete the switching of the optical lens 14, so that the filter can be matched with the corresponding magnification optical lens 14 to better match the absorption characteristics of different components in the near-infrared band, thereby achieving optimized optical irradiation and measurement of components such as fat, protein, and lactose, and improving detection accuracy. The specific operation is as follows: when it is necessary to switch the filter to detect milk samples, the rotary drive motor 4 drives the filter turntable 3 to rotate a certain angle so that the desired filter is rotated to the detection position. At the same time, the first drive shaft 16 rotates synchronously with the filter turntable 3, and drives the first drive disk 19 to rotate. Then, the first telescopic drive rod 25 transmits the power to the second telescopic drive rod 27, which drives the second drive disk to rotate. Finally, the first bevel gear 21 and the second bevel gear 22 change the direction and transmit the power to the switching mounting frame 13, thereby driving the corresponding optical lens 14 to rotate to the inside of the light-transmitting hole 12-1 of the cylindrical light shield 12, thus completing the switching of the optical lens 14. On the other hand, in actual operation, it is necessary to perform regular maintenance or replace different filters inside the device. Therefore, it is necessary to open the top cover of the housing 1. After the cover is opened, the light source module 11 will move away from the cylindrical light shield 12. This solution can ensure that the transmission structure of the magnification switching drive mechanism is not interrupted. The telescopic mounting rod 24 can extend relative to the fixed mounting rod 23. At the same time, the first telescopic transmission rod 25 and the second telescopic transmission rod 27 can extend relative to the intermediate telescopic frame 26. With the top cover of the housing 1 and the light source module 11 moving away, the first bevel gear 21 and the second bevel gear 22 can always maintain meshing, which facilitates the subsequent high-precision component detection work.

[0047] In summary, by sharing the power of the rotary drive motor 4, the synchronous switching of the filter and optical lens 14 is achieved, which not only improves the coordination and detection accuracy of the optical system, but also simplifies the drive structure and reduces the complexity and cost of the overall device. Furthermore, the telescopic transmission design ensures that the transmission chain remains connected when the cover is opened for maintenance or filter replacement, avoiding repeated calibration and improving the maintainability and long-term stability of the equipment.

[0048] Example 2 Combination Figures 1-5 The working principle of the online multi-component milk analysis device in this embodiment is as follows: After the device is started, liquid milk is delivered to the milk sample container 2 through the sample injection pipe at a constant flow rate by a peristaltic pump, forming a stable, uniform and bubble-free liquid layer, providing consistent sample conditions for optical detection.

[0049] The broadband near-infrared light source module 11 in the supplementary lighting mechanism emits a beam of light, which is guided by the cylindrical light shield 12 and passes through the light-transmitting hole 12-1 on it to irradiate the surface of the milk sample at an incident angle of about 45°, thereby enhancing the diffuse reflection inside the sample and suppressing specular reflection interference.

[0050] The rotary drive motor 4 drives the filter turntable 3 to rotate, causing filters with different characteristic wavelengths mounted on the turntable to sequentially enter the optical path, corresponding to the characteristic absorption bands of fat, protein, and lactose, respectively, thereby achieving multi-band selective spectral detection. Simultaneously, through a linkage mechanism consisting of a drive shaft, drive disc, bevel gear assembly, and telescopic drive rod, the optical magnification switching mechanism is driven to operate synchronously, switching the optical magnification lens matched to each filter into the optical path and automatically adjusting the beam divergence angle and irradiation energy to optimize the optical detection conditions for different components.

[0051] Furthermore, to suppress random errors caused by the thermal drift and lighting delay of the halogen lamp in the detection, the system activates the relay to light the halogen lamp 10ms before the filter turntable 3 is about to rotate to the target filter position, allowing the light source to complete a short preheating. After the filter enters the optical path, the light intensity is already stable; before the filter is ready to switch to the next position, the microcontroller controls the relay to turn off the halogen lamp, forming a precise wavelength switching rhythm of "light → measure → off", achieving continuous and accurate selection of characteristic bands.

[0052] The multi-axis robotic arm 10 drives a high-sensitivity photodetector to flexibly adjust its position and attitude in space, enabling it to accurately receive the light signal diffusely reflected from the milk sample. The photodetector converts the light signal into a weak current signal, which is then converted into a voltage signal by the IV conversion module and amplified. The data acquisition module 7 then converts it into digital spectral data in real time, which is finally transmitted to a computer or embedded analysis module. The preset quantitative analysis model is used to calculate and output the content of fat, protein and lactose in the milk.

[0053] The entire testing process is completed automatically under the coordination of the embedded control system, realizing full automation from sample introduction, optical path switching, signal acquisition to component analysis. It features speed, accuracy, portability, and suitability for continuous on-site testing.

[0054] The above are preferred embodiments of the present invention, but the embodiments of the present invention are not limited to the above content. Any changes, modifications, substitutions, combinations, or simplifications made without departing from the spirit and principle of the present invention shall be considered equivalent substitutions and shall be included within the protection scope of the present invention.

Claims

1. A multi-component online analysis device for milk, characterized in that, It includes the housing and the milk sample container, filter switching mechanism, detection and execution mechanism, and supplementary lighting mechanism installed inside the housing; The milk sample container is used to hold the milk sample to be tested; The filter switching mechanism includes a filter turntable and a rotation drive mechanism for driving the filter turntable to rotate. The filter turntable is provided with multiple filter mounting holes, and different filter sheets are provided in different filter mounting holes. The detection actuator includes a photoelectric detection module and a detection drive mechanism for driving the photoelectric detection module to move in space. When the photoelectric detection module is in operation, it detects the milk sample in the milk sample container through the filter on the filter turntable. The supplementary lighting mechanism includes a light source module and a cylindrical light shield. The light source module is located inside the cylindrical light shield, and the cylindrical light shield has a light-transmitting hole. When the light source module is in operation, the light is projected onto the milk sample container through the light-transmitting hole.

2. The online multi-component analysis device for milk according to claim 1, characterized in that, The milk sample container is connected to the milk inlet pipe and the milk outlet pipe, respectively.

3. The online multi-component milk analysis device according to claim 1, characterized in that, The rotary drive mechanism includes a rotary drive motor, the output shaft of which is connected to the filter turntable.

4. The online multi-component analysis device for milk according to claim 3, characterized in that, The supplementary lighting mechanism also includes an optical magnification switching mechanism, which includes a switching mounting frame, optical lenses, and a magnification switching drive mechanism. The switching mounting frame is rotatably connected to the top of the housing via a rotating cylinder, and the switching mounting frame is provided with multiple lens mounting slots. The light source module is located inside the switching mounting frame. The optical lenses are provided with multiple lenses, each with an optical magnification corresponding to multiple filters. The multiple optical lenses are evenly arranged in a circular pattern around the axis of the rotating cylinder on the outside of the light source module.

5. The online multi-component milk analysis device according to claim 4, characterized in that, The rate switching drive mechanism includes a rate switching drive motor and a rate switching transmission assembly. The rate switching drive motor is composed of the rotary drive motor. The rate switching transmission assembly includes a synchronous transmission assembly and a telescopic assembly. The synchronous transmission assembly includes a drive shaft, a drive disc, and a bevel gear assembly. The drive shaft includes a first drive shaft, a second drive shaft, and a third drive shaft. The drive disc includes a first drive disc and a second drive disc. The bevel gear assembly includes a first bevel gear and a second bevel gear. The telescopic assembly includes a telescopic mounting assembly and a telescopic transmission assembly. The telescopic mounting assembly includes a fixed mounting component and a telescopic mounting component. The telescopic transmission assembly includes a first telescopic transmission rod, an intermediate telescopic frame, and a second telescopic transmission rod.

6. The online multi-component analysis device for milk according to claim 5, characterized in that, One end of the first drive shaft is fixedly connected to the center of the filter disc turntable, and the other end of the first drive shaft rotatably passes through the fixed mounting member and is coaxially fixedly connected to the first drive disk; one end of the second drive shaft is rotatably connected to one end of the telescopic mounting member, and the other end of the second drive shaft is coaxially connected to the first bevel gear and the second drive disk, which are fixedly connected; the third drive shaft is vertically arranged, one end of which is fixedly connected to the bottom of the switching mounting bracket, and the second bevel gear is rotatably connected to the third drive shaft, which passes through and is limited in position. The other end of the telescopic mounting component is telescopically connected to the fixed mounting component; one end of the first telescopic transmission rod is eccentrically connected to the first transmission disc via a universal joint structure, and the other end of the first telescopic transmission rod is telescopically connected to the intermediate telescopic frame; one end of the second telescopic transmission rod is eccentrically connected to the second transmission disc via a universal joint structure, and the other end of the second telescopic transmission rod is telescopically connected to the intermediate telescopic frame; both the first and second telescopic transmission rods are electromagnet structures, and the first telescopic transmission rod is in contact with the second telescopic transmission rod in the fully retracted state.

7. The online multi-component analysis device for milk according to claim 1, characterized in that, The photoelectric detection module is a high-sensitivity photoelectric detector used to detect the photoelectric signal of the milk sample and transmit the photoelectric signal to the I-V conversion module. The I-V conversion module converts the signal into a voltage signal and amplifies it. The amplified voltage signal is transmitted to the data acquisition module and converted into a digital signal in real time. The data acquisition module sends the digital spectral data to a computer or embedded analysis module through a high-speed communication interface for model analysis of fat, protein, and lactose content.

8. The online multi-component analysis device for milk according to claim 7, characterized in that, The photodetector is installed at the input of the I–V conversion module. The spectral response range of the photodetector is 900–2100 nm, and the diameter of the photosensitive surface is 1000 μm.

9. The online multi-component analysis device for milk according to claim 1, characterized in that, The detection drive mechanism is a multi-axis robotic arm, and the photoelectric detection module is located at the end of the multi-axis robotic arm.

10. The online multi-component analysis device for milk according to claim 1, characterized in that, The light source module is a broadband near-infrared light source module. After the light beam emitted by the broadband near-infrared light source module passes through a filter, it illuminates the milk sample container at an incident angle of 45°±5°.

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