Electronic nose device with double gas inlet channels and gas detection method

Abstract

The invention relates to the field of gas detection, and discloses an electronic nose device with double gas inlet channels and a gas detection method. A filter, a double-cavity air inlet shell with a front-narrow rear-wide structure and a sensor annular placing hole, an air flow guide structure, a sensor array and an air exhaust shell are manufactured in a 3D printing mode; the sensor array is fixedly connected with the gas flow guide structure; the outer wall of the gas guide device is in contact with the inner wall of the gas inlet shell and is fixed in a magnetic attraction manner; the air exhaust shell is connected with an air pump through a rubber tube; the gas inlet shell and the gas exhaust shell are spliced together in a stepped mode, the purpose of detaching and replacing the sensors can be achieved, and through unique sensor combination and an advanced data processing algorithm, the components and concentration of target gas can be rapidly recognized and quantitatively analyzed. According to the invention, the contact time of the gas and the sensor is prolonged while rapid suction of the gas is guaranteed, and efficient and accurate detection of various different types of gas is realized.

Description

Technical Field

[0001] The present invention relates to the field of gas detection, and in particular to an electronic nose device with double air inlet cavities and a gas detection method. Background Art

[0002] There are thousands of gases containing different molecules in the natural environment we live in. The smells emitted by these gases often contain a lot of useful information that can be used for detection and identification. For example, plants use the smell they emit to attract animals to achieve the purpose of pollination; the smell of food can help us identify the type, freshness and cooking method of food; the smell emitted by fruits at different growth stages or during storage can help us monitor its growth process and also help us determine whether it meets the requirements for picking; in the production of some high-risk industries, smell can help us identify certain chemicals, such as gas, smoke, detergents, etc., and this information can help us avoid danger; in addition, in medicine, by analyzing the composition of human exhaled gas, it can provide doctors with useful information for diagnosis, which to a certain extent increases the possibility of early detection and early treatment of diseases. Gas detection and response mechanisms are of great value, and at the same time, these studies need to meet the requirements of efficiency, speed and accuracy.

[0003] Traditional gas detection technologies mainly include gas chromatography, mass spectrometry, infrared absorption spectroscopy, Raman spectroscopy, ultraviolet-visible absorption spectroscopy, etc. These technologies have relatively mature theories and practical applications and can detect a variety of gases, but they have shortcomings in terms of sensitivity, specificity and real-time performance.

[0004] The emerging gas detection technology electronic nose has attracted much attention due to its advantages such as fast response, high sensitivity, good real-time performance and no interference. However, it also faces problems such as high technical difficulty, high cost and large device size. Therefore, how to reduce the size of the electronic nose device and expand the gas detection method with a wide range of applications has become an urgent problem to be solved. Summary of the invention

[0005] The present invention aims to provide an electronic nose device with dual air inlet cavities and a gas detection method, which can dynamically detect gas with fast detection speed and accurate results. The device is small, integrated and portable, reducing the burden on inspectors.

[0006] The electronic nose device with dual air inlet channels and the gas detection method of the present invention are characterized in that the device comprises a filter 1, a dual air inlet housing 2, an air extraction housing 3, a sensor array 4, and a gas guide structure 5;

[0007] The dual-cavity air intake shell 2 is a cylindrical structure, and its interior imitates the shape of the canine nasal cavity which is narrow in front and wide in the back, so that during the entire inhalation process, the gas can absorb more gas with a fast speed in the early stage and ensure the contact time between the gas and the sensor with a slow speed in the later stage, and a sensor annular placement hole is designed on the surface of the cylindrical structure. The annularly arranged sensor can collect the gas molecules reflected and refluxed on the wall of the exhaust shell, which provides more data points for detection. These data points can complement and verify each other. A handle is designed on the top for easy holding. If it is inverted, the handle can play a supporting role and can be placed on a plane for gas detection. Magnetic material is added to the front end of the shell to ensure that the gas The flow guide structure 5 does not undergo displacement changes during operation; the sensor array 4 has four sensor placement holes, which are evenly distributed on the circumference of the vertical plane, and a variety of sensor combinations can be performed to improve the accuracy and reliability of detection; the exterior of the vacuum shell 3 is a cylindrical structure; the gas flow guide structure 5 is consolidated with the sensor array 4 to form a gas detection module, which can ensure that the airflow is evenly distributed in the chamber and the flow rate is stable; the filter 1 is fixed to the front end of the two air inlets of the dual-cavity air inlet shell 2 to prevent foreign particles from entering the electronic nose air chamber; the rear end of the dual-cavity air inlet shell 2 and the front end of the vacuum shell 3 are spliced ​​together in a stepped manner; the vacuum shell 3 is connected to the air pump through a rubber hose, and the air pump performs negative pressure suction to provide power for gas inhalation.

[0008] Designing a gas diversion structure in the nasal cavity of the electronic nose can guide the flow of gas, prompting the gas to contact the sensor more quickly and more, and slowing down the outflow time to make the contact more complete, thereby improving the detection sensitivity of the electronic nose device.

[0009] It uses a unique combination of sensors, including metal oxide semiconductor sensors, electrochemical sensors, and optical sensors. These sensors have different sensitivities and selectivities for different types of gases, and through combination, it can achieve comprehensive detection of multiple target gases. The sensors are strictly calibrated before use to ensure the accuracy and stability of the test results.

[0010] The collected sensor data is preprocessed, including data filtering, normalization, and removal of outliers. Data filtering can use methods such as mean filtering, median filtering, or Kalman filtering to effectively remove noise interference in sensor signals. Normalization processing includes minimum-maximum normalization or Z-score normalization, so that the data of different sensors are in the same dimension, which is convenient for subsequent analysis. By removing outliers, the reliability of the data is improved. The preprocessed data is analyzed using advanced data processing algorithms. The machine learning algorithm at least includes the support vector machine (SVM) algorithm, which can accurately classify and identify the characteristics of different gases; the deep learning algorithm at least includes the convolutional neural network (CNN), which can automatically extract high-level features from the data and improve the accuracy of detection. In addition, machine learning algorithms can also include random forest algorithms, artificial neural network algorithms, etc., and deep learning algorithms can also include recurrent neural networks, long short-term memory networks, etc., to adapt to different gas detection tasks.

[0011] According to the results of algorithm analysis, the composition and concentration of the target gas are determined. Through the comprehensive application and optimization of multiple algorithms, high-precision gas detection can be achieved, providing strong support for safe production and environmental monitoring.

[0012] The beneficial effects of the present invention are:

[0013] 1. The shape of the canine nasal cavity is narrow in front and wide in the back, so that the structure with narrow front and wide back forms a smaller entrance when the gas enters the detection area, which helps to accelerate the flow of gas and increase the contact area between the gas and the detector. Secondly, the increase in the width of the rear part of the structure can effectively reduce the diffusion and mixing of the gas during the flow process, thereby maintaining a high gas concentration, the change of the gas flow rate is small and tends to be stable, there is no obvious periodic or random change, and the flow field remains relatively stable; the sensor of the annular array can collect the gas molecules reflected and refluxed on the wall, providing more data points; the gas guide structure can act as a connecting device and greatly reduce the overall weight, and can ensure that the internal flow field is evenly distributed in space; for different gas detection environments, only the disassembly connection needs to be opened and a new sensor can be replaced; different sensors can be combined to perform multi-gas simultaneous detection, which helps to improve the detection efficiency. This not only ensures the reliability of the electronic nose device, but also greatly improves its reuse rate, and has the characteristics of convenient and fast equipment replacement.

[0014] 2. Through the unique combination of sensors and advanced data processing algorithms, high-precision detection of gas composition and concentration can be achieved, reducing false alarms and missed alarms. The sensor is calibrated and data preprocessed, and the algorithm is optimized, making the detection results more stable and reliable, and not affected by environmental factors. If equipped with a communication module, the detection results can be transmitted to external devices to achieve remote monitoring and data sharing, so that users can understand the gas detection situation anytime and anywhere. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 A cross-sectional view of an electronic nose device with dual air inlet cavities;

[0016] Figure 2 A partial cross-sectional view of the front view of the filter;

[0017] Figure 3 It is a partial cross-sectional view of the left side of the filter;

[0018] Figure 4 is a front view of the gas guide structure;

[0019] Figure 5 It is a left view of the gas guide structure;

[0020] Figure 6 is a front view of the sensor array structure;

[0021] Figure 7 It is the left view of the sensor array structure;

[0022] Figure 8 It is a partial cross-sectional view of the front view of the air intake housing;

[0023] Fig. 9 is a front view of the exhaust shell;

[0024] Fig.10 It is a left side view of the exhaust shell;

[0025] Fig.11 The working principle of the electronic nose device with dual air inlet cavities. DETAILED DESCRIPTION

[0026] The present invention provides an electronic nose device with dual air inlet cavities and a gas detection method, which will be further described below in conjunction with the accompanying drawings and specific embodiments.

[0027] like Figure 1The embodiment of the present invention shown in the figure, the main working device includes: the device includes a filter 1, a dual-cavity air intake shell 2, an exhaust shell 3, a sensor array 4, and a gas guide structure 5. The dual-cavity air intake shell 2 is a cylindrical structure, and a handle is designed on the top for easy holding. If it is inverted, the handle can play a supporting role, and it can be placed on a plane for gas detection. Magnetic material is added to the front end part, and the magnetic force can ensure that the gas guide structure 5 does not change during operation; the sensor array 4 is fixed with the gas guide structure 5 to form a gas detection module, which can ensure that the airflow is evenly distributed in the chamber and the flow rate is stable; the filter 1 is fixed to the front end of the two air inlets of the dual-cavity air intake shell 2, which can prevent foreign particles from entering the electronic nose air chamber; the rear end of the dual-cavity air intake shell 2 and the front end of the exhaust shell 3 are spliced ​​together in a stepped manner; the exhaust shell 3 is connected to the air pump through a rubber hose, and the air pump performs negative pressure exhaust to provide power for gas inhalation.

[0028] When the air pump is turned on, the gas to be tested is sucked into the portable electronic nose device with dual air inlet cavities. Since a gas guide structure 5 is placed at the tail end of the air inlet, it divides the airflow into two parts, inner and outer, so that the flow field is evenly distributed, the gas has different flow rates, and the gas flow rate flowing through the sensor is stable. More gas flows through the sensor surface on the sensor array 4, and the time the gas stays on the sensor surface will also increase. After the gas contacts the sensor, part of it is extracted from the air extraction hole, and part of it rebounds and flows back to contact the annularly arranged sensor.

[0029] The sensor transmits the obtained data to the computer, and uses methods such as mean filtering, median filtering or Kalman filtering to filter the sensor data; select the appropriate normalization method according to the characteristics of the data, such as minimum-maximum normalization or Z-score normalization, to convert the data of different sensors to the same dimension to facilitate subsequent data processing and analysis; use methods based on sensor characteristics to identify and remove outliers. Data points that obviously deviate from the normal range can be considered outliers and removed; the SVM model accurately classifies the detected gas into different gas categories based on the characteristics of the sensor data; for sensor array data with spatial distribution characteristics, CNN is used to automatically extract spatial features in the data.

[0030] This embodiment is only a preferred specific implementation of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed by the present invention should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims

1. An electronic nose device with dual air inlet channels and a gas detection method, characterized in that: The device comprises a filter 1, a dual-cavity air intake housing 2, an air extraction housing 3, a sensor array 4, and a gas flow guiding structure 5; The gas detection method comprises the following steps: Utilize a unique sensor combination to collect data on the target gas, the sensor combination including but not limited to metal oxide semiconductor sensors, electrochemical sensors and optical sensors; Preprocessing the collected sensor data includes data filtering, normalization, and removal of outliers; The preprocessed data is analyzed using advanced data processing algorithms, wherein the data processing algorithms include machine learning algorithms and deep learning algorithms, wherein the machine learning algorithms at least include support vector machine (SVM) algorithms, and the deep learning algorithms at least include convolutional neural networks (CNN).

2. The electronic nose device with dual air inlet channels according to claim 1, characterized in that: The dual-cavity air inlet housing 2 is cylindrical in structure, and its interior imitates the shape of the canine nasal cavity, which is narrow in front and wide in the back, so that during the entire inhalation process, the gas can absorb more gas at a fast speed in the early stage and can ensure the contact time between the gas and the sensor at a slow speed in the later stage. A sensor annular placement hole is designed on the surface of the cylindrical structure. The annularly arranged sensor can collect gas molecules reflected and refluxed from the wall of the vacuum shell, which provides more data points for detection. These data points can complement and verify each other. A handle is designed on the top for easy holding. If it is inverted, the handle can serve as a support and can be placed on a plane for gas detection. Magnetic material is added to the front end of the shell, which can ensure that the gas guide structure 5 does not change in displacement during operation through magnetic force.

3. The electronic nose device with dual air inlet channels according to claim 1, characterized in that: The exterior of the air extraction housing 3 is a cylindrical structure.

4. The electronic nose device with dual air inlet channels according to claim 1, characterized in that: The sensor array 4 has four sensor placement holes evenly distributed on the circumference of the vertical plane, and multiple sensor combinations can be performed to improve the accuracy and reliability of detection.

5. The electronic nose device with dual air inlet channels according to claim 1, characterized in that: The gas guide structure 5 is fixed to the sensor array 4 to form a gas detection module, which can guide the flow of gas, ensure that the gas flow is evenly distributed in the chamber, the flow rate is stable, promote more complete contact between the gas and the sensor, and slow down its outflow time.

6. The electronic nose device with dual air inlet channels according to claim 1, characterized in that: The filter screen 1 is fixedly connected to the front ends of the two air inlets of the dual-cavity air inlet housing 2 to prevent foreign particles from entering the air chamber of the electronic nose.

7. The electronic nose device with dual air inlet channels according to claim 1, characterized in that: The rear end of the double-cavity air inlet housing 2 and the front end of the air exhaust housing 3 are spliced ​​together in a stepped manner.

8. The electronic nose device with dual air inlet channels according to claim 1, characterized in that: The air pump housing 3 is connected to the air pump via a rubber hose, and the air pump performs negative pressure air extraction to provide power for gas inhalation.

9. The gas detection method according to claim 1, characterized in that: The data filtering adopts one or more of mean filtering, median filtering or Kalman filtering.

10. The gas detection method according to claim 1, characterized in that: The normalization process includes minimum-maximum normalization or Z-score normalization.

11. The gas detection method according to claim 1, characterized in that: The machine learning algorithm also includes a random forest algorithm and an artificial neural network algorithm.

12. The gas detection method according to claim 1, characterized in that: The deep learning algorithm also includes recurrent neural networks and long short-term memory networks.

13. The electronic nose device with dual air inlet channels according to claim 1, characterized in that: The device is compact in design, easy to carry and install, and can be widely used in multiple gas detection scenarios such as chemical industry, environmental protection, mining, smart home, etc.

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