Electronic nose device for gas composition analysis and method of operation thereof

Abstract

The present application relates to the field of gas component analysis, in particular to an electronic nose device for gas component analysis and a working method thereof. The electronic nose device comprises a simulated nose, an air passage and an air inlet and outlet control assembly. The simulated nose comprises a telescopic container, a sensor array in the container and a telescopic power mechanism. The sensor array in the container is installed at the bottom of the telescopic container, and the telescopic power mechanism is connected to the top of the telescopic container. One end of the air passage is communicated with the telescopic container and is provided with an air passage sensor array. The air inlet and outlet control assembly comprises a control pipe, a plug and a magnetic door. The control pipe has an air inlet section, an intermediate section and an air outlet section communicated in sequence. The other end of the air passage is communicated with the intermediate section, and the end face of the air inlet section away from the intermediate section is provided with an air inlet. The plug is slidably fitted in the air inlet section, has a plugging part at the middle part and a plurality of through holes at positions deviated from the plugging part. The magnetic door is installed on the end face of the air outlet section away from the intermediate section. The present application has a light structure and good detection effect.

Description

Technical Field

[0001] This invention relates to the field of gas composition analysis, and more specifically to an electronic nose device for gas composition analysis and its operating method. Background Technology

[0002] Electronic noses are designed to mimic the human olfactory system, monitoring volatile organic compounds in the environment by detecting and identifying odors. The development of this technology is driven by a variety of needs, including the need for automated, continuous monitoring of the environment and food safety in industrial processes, as well as the limitations of traditional methods relying on human olfaction, such as subjectivity, fatigue, and lack of quantification.

[0003] The PEN series electronic nose from the German company AIRSENSE uses activated carbon to purify the air passage. It is relatively large and requires two air pumps and a flow meter to perform the sampling and cleaning processes. Furthermore, this series of electronic noses has high power consumption and a low sampling rate; 40 seconds out of a one-minute measurement time are spent expelling the gas sample.

[0004] Therefore, there is an urgent need to design an electronic nose with better performance. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to overcome the defects of the prior art and provide an electronic nose device for gas composition analysis. It has a lightweight structure, meets the requirements of real-time and portability for on-site detection, and has good detection effect.

[0006] To solve the above-mentioned technical problems, the technical solution of the present invention is: an electronic nose device for gas composition analysis, comprising:

[0007] The simulated nose includes a retractable container, an array of sensors inside the container, and a telescopic power mechanism. The array of sensors inside the container is installed at the bottom inside the retractable container, and the telescopic power mechanism is connected to the top of the retractable container to drive the retractable container to compress and stretch.

[0008] An airway, one end of which is connected to the retractable container, and an airway sensor array is provided inside the airway.

[0009] An air intake / exhaust control assembly includes a control tube, a plug, and a magnetic door. The control tube has an intake section, a middle section, and an exhaust section connected in sequence. The other end of the air passage is connected to the middle section. An intake port is provided on the end face of the intake section away from the middle section. The plug is slidably fitted within the intake section, and its middle portion has a blocking part protruding towards the intake port for sealing the intake port. Multiple through holes are provided on the plug at positions offset from the blocking part for allowing gas to enter the middle section. The magnetic door is installed on the end face of the exhaust section away from the middle section and is configured to open only outwards. The opening resistance of the magnetic door is greater than the sliding resistance of the plug.

[0010] Furthermore, the sensor array inside the container and / or the sensor array inside the airway includes a temperature and humidity sensor and / or a pressure sensor and / or a hydrogen sensor and / or a hydrogen sulfide gas sensor and / or an alcohol sensor and / or a volatile gas sensor and / or an ammonia gas sensor and / or a carbon monoxide sensor and / or a breath gas sensor and / or an air quality sensor and / or a gas sensor and / or a nitrogen dioxide gas sensor and / or a smoke gas sensor.

[0011] Furthermore, the multiple sensors in the sensor array inside the container are arranged in a star-shaped pattern, a planar matrix pattern, or a single-column pattern.

[0012] Furthermore, the air passages are multiple, the sensor array inside the container is located at the center of the bottom inside the retractable container, and the multiple air passages are arranged radially outward from the outer periphery of the area where the sensor array is located inside the container, with the outward ends of the air passages extending outside the retractable container.

[0013] Furthermore, the retractable container is equipped with an electromagnetic induction wireless charging module, which is used to charge the sensor array inside the container and / or the sensor array inside the airway.

[0014] Furthermore, it also includes a wireless communication module, which connects the sensor array inside the container and the sensor array inside the airway, and is used to send out the data detected by the sensor array inside the container and the sensor array inside the airway.

[0015] The present invention also provides a method for operating an electronic nose device for gas composition analysis, the method comprising:

[0016] During the air intake process, when the retractable power mechanism drives the retractable container to stretch, the blockage slides away from the air intake under atmospheric pressure, the air intake is opened, and the gas enters the retractable container in sequence through the air intake, the blockage through hole, the intermediate section and the air passage.

[0017] During the exhaust process, as the retractable power mechanism compresses the retractable container, the airflow pushes the blockage towards the air inlet, sealing the inlet. This causes the air pressure inside the retractable container to rise, increasing the gas concentration. When the pressure difference between the internal and external surfaces exceeds the maximum magnetic force of the magnetic door, the door opens outwards, allowing the gas to escape.

[0018] During the intake and exhaust processes, both the sensor array inside the container and the sensor array inside the air passage detect the gas.

[0019] By adopting the above technical solution, the present invention has the following beneficial effects:

[0020] 1. This invention uses a push-pull method for air intake and exhaust, which can quickly collect gas samples and exhaust the exhaust gas, making each test more accurate. The whole device has a simple structure and is relatively lightweight, meeting the needs of on-site testing for real-time performance and portability.

[0021] 2. When the retractable power mechanism compresses the retractable container, the airflow is faster, which pushes the blockage into the air inlet, preventing the gas from flowing. The purpose of this is to increase the air pressure inside the retractable container, thereby increasing the concentration. The gas molecules inside the retractable container become more concentrated, allowing them to fully contact the sensors in the sensor array inside the container, which is more conducive to accurate gas detection.

[0022] 3. The electronic nose device of this invention integrates two types of sensor arrays. The in-container sensor array is more suitable for detecting static gases, especially when the expandable container is compressed, as the gas concentration increases, allowing for better detection of static gases. The in-airway sensor array is more suitable for detecting flowing gases. Therefore, the in-container and in-airway sensor arrays can complement each other, accurately detecting various gas data. This complementary effect improves system stability and results in better detection performance. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the electronic nose device for gas composition analysis according to the present invention;

[0024] Figure 2 This is a schematic diagram of the internal structure of the expandable container for gas composition analysis according to the present invention;

[0025] Figure 3 This is a schematic diagram of the structure of the air intake / exhaust control assembly of the present invention;

[0026] Figure 4 This is a schematic diagram of the blockage structure of the present invention;

[0027] Figure 5 This is a diagram showing the arrangement of sensors in the sensor array inside the container of the present invention;

[0028] Figure 6 This is a diagram showing the arrangement of sensors within the airway sensor array of the present invention.

[0029] Figure 7 This is a schematic diagram of the wireless receiving circuit of the electromagnetic induction wireless charging module of the present invention.

[0030] Figure 8 This is a circuit diagram of the sensor power supply module and the sensor circuit module of the present invention;

[0031] In the diagram, 1. Retractable container; 2. Sensor array inside the container; 3. Retractable power mechanism; 4. Air passage; 5. Sensor array inside the air passage; 6. Control tube; 61. Air inlet; 7. Blockage; 71. Sealing part; 72. Through hole; 8. Magnetic door; 9. Electromagnetic induction wireless charging module. Detailed Implementation

[0032] To make the content of this invention easier to understand, the invention will be further described in detail below with reference to specific embodiments and accompanying drawings.

[0033] Example 1

[0034] like Figures 1-8 As shown, an electronic nose device for gas composition analysis includes:

[0035] The simulated nose includes a retractable container 1, an internal sensor array 2, and a retractable power mechanism 3. The internal sensor array 2 is installed at the bottom inside the retractable container 1, and the retractable power mechanism 3 is connected to the top of the retractable container 1 to drive the retractable container 1 to compress and stretch.

[0036] Airway 4, one end of which is connected to retractable container 1, and an airway sensor array 5 is installed inside airway 4.

[0037] The air intake / exhaust control assembly includes a control pipe 6, a plug 7, and a magnetic door 8. The control pipe 6 has an intake section, an intermediate section, and an exhaust section connected in sequence. The other end of the air passage 4 is connected to the intermediate section. An intake port 61 is provided on the end face of the intake section away from the intermediate section. The plug 7 is slidably fitted in the intake section, and its middle part has a plugging part 71 that protrudes toward the intake port 61 and is used to block the intake port 61. Multiple through holes 72 are provided on the plug 7 at positions away from the plugging part 71 for allowing gas to enter the intermediate section. The magnetic door 8 is installed on the end face of the exhaust section away from the intermediate section and is configured to open only outwards. The opening resistance of the magnetic door 8 is greater than the sliding resistance of the plug 7.

[0038] Specifically, this embodiment uses a push-pull method for air intake and exhaust, which can quickly collect gas samples and exhaust the detected exhaust gas, making each test more accurate. The entire device has a simple structure and is relatively lightweight, meeting the requirements of real-time and portability for on-site testing. When the retractable power mechanism 3 drives the retractable container 1 to extend, the plug 7 slides away from the air inlet 61 under atmospheric pressure, opening the air inlet 61. Gas then enters the retractable container 1 sequentially through the air inlet 61, the through hole 72 of the plug 7, the middle section, and the air passage 4. When the retractable power mechanism 3 drives the retractable container 1 to compress, the airflow is faster, pushing the plug 71 of the plug 7 into the air inlet 61, thus preventing gas flow. The purpose of this is to increase the gas pressure inside the retractable container 1, thereby increasing the concentration. The gas molecules inside the retractable container 1 become more concentrated, allowing for full contact with the sensors in the sensor array 2 inside the container, which is more conducive to accurate gas detection. The magnetic door 8 is used to exhaust gas when opened. The door is hinged to the control pipe 6. Magnets or electromagnets are respectively installed on opposite sides of the control pipe 6 and the magnetic door 8. When the difference between the internal and external air pressure is greater than the maximum magnetic force of the magnetic door 8, the gas pushes the magnetic door 8 open, thereby exhausting the gas. This ensures that very little exhaust gas remains in the retractable container 1, reducing the need for exhaust gas treatment devices, speeding up the experimental process, and making the entire device relatively lightweight. Furthermore, the electronic nose device in this embodiment integrates two types of sensor arrays. The in-container sensor array 2 is more suitable for detecting static gases, especially when the retractable container 1 is compressed, as the gas concentration increases, allowing for better detection of static gases. The in-airway sensor array 5 is more suitable for detecting flowing gases. Therefore, the in-container sensor array 2 and the in-airway sensor array 5 can complement each other, accurately detecting various gas data, improving system stability through complementary effects, and achieving good detection results.

[0039] In this embodiment, as Figure 1 As shown, the retractable container 1 has creases and can be compressed to a position with a slight gap between the bottom and the sensor array 2 inside the container, thus venting gas as completely as possible. Furthermore, the retractable container 1 used in this embodiment has a volume of 300ml. Since the cycle of a person's rapid breathing is approximately 0.76 seconds, the compression speed can be roughly calculated to be 2.4cm / s, or approximately 0.1km / h. Therefore, the compression and extension speed of the telescopic power mechanism 3 is controlled at 0.1km / h. This design aims to better reflect real-world scenarios and reduce the number of times gas is expelled.

[0040] In this embodiment, the in-airway sensor array 5 can be composed of low-power MEMS sensors with good gas flow sensitivity. These MEMS sensors are more sensitive to flowing gas compared to the sensors at the bottom of the device. These sensors are typically small, low-power, diverse, highly integrated, and have a sensitivity R0 (in air) / Rs (in 1000ppm H2) generally greater than 5. However, they are significantly affected by temperature and humidity. Therefore, the best approach is to place temperature and humidity sensors inside the retractable container 1. External calibration is used to control the ambient temperature at 20±2℃ and the ambient humidity at 55%±5RH. This allows for more accurate and stable sensor detection. This detection method better reflects the human experience of smelling gas.

[0041] In this embodiment, the multiple sensors of the sensor array 2 inside the container are arranged in a star-shaped pattern, a planar matrix pattern, or a single-column pattern. Figure 5 This embodiment shows one arrangement of multiple sensors in the container sensor array 2, which is a planar matrix arrangement. Similarly, 6 shows one arrangement of multiple sensors in the airway sensor array 5, which is a single-row arrangement.

[0042] In this embodiment, the in-container sensor array 2 and / or the in-airway sensor array 5 include a temperature and humidity sensor, a pressure sensor, a hydrogen sensor, a hydrogen sulfide gas sensor, an alcohol sensor, a volatile gas sensor, an ammonia gas sensor, a carbon monoxide sensor, a breath gas sensor, an air quality sensor, a fuel gas sensor, a nitrogen dioxide gas sensor, and a smoke gas sensor.

[0043] Among these methods, the acquired data is filtered by temperature and humidity to ensure that the valid data values ​​are obtained at the most suitable temperature and humidity for the sensor.

[0044] In this embodiment, the telescopic power mechanism 3 can adopt various structures, such as a cylinder, an electric cylinder, an electric telescopic rod, etc.

[0045] In this embodiment, a physical barrier can also be set at the dividing point between the air intake section and the middle section of the control pipe 6 to prevent the blockage 7 from sliding into the middle section.

[0046] Example 2

[0047] Based on Example 1, such as Figure 2 As shown, there are multiple air passages 4. The sensor array 2 inside the container is located at the center of the bottom inside the retractable container 1. The multiple air passages 4 are arranged radially outward from the outer periphery of the area where the sensor array 2 is located inside the container, and the outward ends of the air passages 4 extend to the outside of the retractable container 1.

[0048] Gas can enter the expandable container 1 from all directions, and the sensors in the sensor array 2 inside the container can also be arranged in a star shape accordingly. The purpose of doing this is to detect gas data from all directions, making the gas detection more reasonable and realistic.

[0049] Example 3

[0050] Based on Example 1 or Example 2, such as Figure 2 , 7 As shown, an electromagnetic induction wireless charging module 9 is installed inside the retractable container 1. The electromagnetic induction wireless charging module 9 is used to charge the sensor array 2 inside the container and / or the sensor array 5 inside the airway.

[0051] Specifically, wireless power transmission avoids the need for perforation of the device required by wired connections in traditional electronic nose systems, improving the device's airtightness and flexibility.

[0052] like Figure 7 As shown, when the receiving coil is close to the transmitting coil of the electromagnetic induction wireless charging module 9, the receiving coil obtains an AC signal induced electromotive force. The induced electromotive force is rectified by the bridge composed of D1, D2, D3 and D4 and outputs a pulsed DC voltage. The pulsed DC voltage is filtered by capacitors C25, C26 and C27 and outputs a stable VCC. VCC is output as +5V / 1.2A through the L7805 linear regulator.

[0053] like Figure 8 As shown, the power supply modules for both the in-container sensor array 2 and the in-airway sensor array 5 are divided into sensor power supplies and sensor preheating power supplies. The power supply uses a +5V / 1A DC power supply, while the preheating power supply offers +2.8V, +2.5V, +2.0V, and +1.9V. The power supply uses a USB interface for power delivery. The preheating power supply first uses an ASM1117-3.3 linear regulator to regulate the +5V DC power supply to +3.3V, and then uses a voltage divider circuit to distribute +2.8V, +2.5V, +2.0V, and +1.9V respectively.

[0054] The sensors used in this embodiment are the GMV-2021B hydrogen sensor, GM-102B nitrogen dioxide gas sensor, GM-202B smoke sensor, GM-302B alcohol gas sensor, GM-402B combustible gas sensor, GM-502B ethanol / formaldehyde / toluene sensor, GM-602B hydrogen sulfide gas sensor, GM-702B carbon monoxide gas sensor, GM-802B ammonia gas sensor, and GM-512B breath gas sensor, which can detect 10 different types of gases.

[0055] Ten different sensor models are packaged identically, with the effective pins of the sensor chip being pin 1 (RH1), pin 3 (RH2), pin 5 (RS1), and pin 7 (RS2). Pin 7 (RS2) is the sensor power input, and pin 5 (RS1) is connected in series with the adjustable resistor RL to ground to form a power supply loop. Pin 1 (RH1) is the sensor preheating power input, and pin 3 (RH2) is the preheating power ground.

[0056] The 10 different sensor models have the same power supply voltage but different preheating voltages.

[0057] For 10 different sensor models, pin 7 (RS2) is connected to +5V, and pin 5 (RS1) is connected in series with an adjustable resistor RL to ground. Sensors GMV-2021B, GM-102B, GM-202B, GM-302B, GM-502B, GM-702B, and GM-512B have the same warm-up voltage. Pin 1 (RH1) of all these sensors is connected to +2.5V; pin 1 (RH1) of sensor GM-402B is connected to +2.8V; pin 1 (RH1) of sensor GM-602B is connected to +1.9V; and pin 1 (RH1) of sensor GM-802B is connected to +2.0V. Pin 3 (RH2) of all sensors is connected to GND. A capacitor C is connected between pin 7 (RS2) and pin 1 (RH1) of all sensors to filter out signal interference that may be caused by the input power supply. Pin 5 (RS1) is the output terminal for sensor data acquisition and is connected to the I / O pin of the ESP32 chip's 11ADC. The content of the gas to be measured in the air can be identified by reading the output voltage of the RS1 pin of the sensor through a software program.

[0058] Example 4

[0059] Based on Embodiment 1, Embodiment 2, or Embodiment 3, the electronic nose device for gas composition analysis further includes a wireless communication module. The wireless communication module is connected to the sensor array 2 inside the container and the sensor array 5 inside the airway, and is used to send out the data detected by the sensor array 2 inside the container and the sensor array 5 inside the airway.

[0060] Specifically, wireless data transmission avoids the need for perforation of the device required by wired connections in traditional electronic nose systems, improving the device's airtightness and flexibility.

[0061] The data can be uploaded to a computer via a wireless communication module for model training, repeated multiple times, thus utilizing the odors of various objects to complete the data training. When detecting an unknown object, the detected and trained model is compared using a built-in algorithm, and the detection result is transmitted to the computer.

[0062] Example 5

[0063] A method of operating an electronic nose device for gas composition analysis as described in any of Embodiments 1 to 4, the method comprising:

[0064] During the air intake process, when the retractable power mechanism 3 drives the retractable container 1 to stretch, the blockage 7 slides away from the air inlet 61 under atmospheric pressure, the air inlet 61 is opened, and the gas enters the retractable container 1 through the air inlet 61, the through hole 72 of the blockage 7, the intermediate section and the air passage 4 in sequence.

[0065] During the exhaust process, when the retractable power mechanism 3 compresses the retractable container 1, the airflow pushes the blockage 7 towards the air inlet 61, blocking the air inlet 61. The air pressure inside the retractable container 1 rises, and the gas concentration increases. When the difference between the internal and external air pressures exceeds the maximum magnetic force of the magnetic door 8, the magnetic door 8 opens outwards, and the gas is discharged.

[0066] During the intake and exhaust processes, both the sensor array 2 inside the container and the sensor array 5 inside the air passage detect the gas.

[0067] Based on the above-described preferred embodiments of the present invention, and through the foregoing description, those skilled in the art can make various changes and modifications without departing from the inventive concept. The technical scope of this invention is not limited to the contents of the specification, but must be determined according to the scope of the claims.

Claims

1. An electronic nose device for gas composition analysis, characterized in that, include: The simulated nose includes a retractable container (1), an in-container sensor array (2), and a telescopic power mechanism (3). The in-container sensor array (2) is installed at the bottom inside the retractable container (1), and the telescopic power mechanism (3) is connected to the top of the retractable container (1) to drive the retractable container (1) to compress and stretch. An airway (4) is connected at one end to the retractable container (1), and an airway sensor array (5) is provided inside the airway (4); The air intake and exhaust control assembly includes a control tube (6), a plug (7), and a magnetic door (8). The control tube (6) has an intake section, an intermediate section, and an exhaust section connected in sequence. The other end of the air passage (4) is connected to the intermediate section. An intake port (61) is provided on the end face of the intake section away from the intermediate section. The plug (7) is slidably fitted in the intake section, and its middle part has a blocking part (71) protruding toward the intake port (61) and used to block the intake port (61). Multiple through holes (72) for allowing gas to enter the intermediate section are provided at the position of the plug (7) away from the blocking part (71). The magnetic door (8) is installed on the end face of the exhaust section away from the intermediate section and is configured to open only outward. The opening resistance of the magnetic door (8) is greater than the sliding resistance of the plug (7). The air passage (4) has multiple air passages. The sensor array (2) inside the container is located at the center of the bottom inside the retractable container (1). The multiple air passages (4) are arranged radially outward from the outer periphery of the area where the sensor array (2) is located inside the container. The outward end of the air passage (4) extends to the outside of the retractable container (1). The operating method of an electronic nose device for gas composition analysis includes: During the air intake process, when the telescopic power mechanism (3) drives the telescopic container (1) to stretch, the blockage (7) slides away from the air inlet (61) under atmospheric pressure, the air inlet (61) is opened, and the gas enters the telescopic container (1) through the air inlet (61), the through hole (72) of the blockage (7), the middle section and the air passage (4) in sequence. During the exhaust process, when the telescopic power mechanism (3) compresses the telescopic container (1), the airflow pushes the blockage (7) towards the air inlet (61), and the air inlet (61) is blocked by the sealing part (71). The air pressure inside the telescopic container (1) rises, and the gas concentration increases. When the difference between the internal air pressure and the external air pressure is greater than the maximum magnetic attraction force of the magnetic door (8), the magnetic door (8) opens outward, and the gas is discharged. During the intake and exhaust processes, both the sensor array (2) inside the container and the sensor array (5) inside the air passage detect the gas.

2. The electronic nose device for gas composition analysis according to claim 1, characterized in that, The in-container sensor array (2) and / or the in-airway sensor array (5) include a temperature and humidity sensor and / or a pressure sensor and / or a hydrogen sensor and / or a hydrogen sulfide gas sensor and / or an alcohol sensor and / or a volatile gas sensor and / or an ammonia gas sensor and / or a carbon monoxide sensor and / or a breath gas sensor and / or an air quality sensor and / or a gas sensor and / or a nitrogen dioxide gas sensor and / or a smoke gas sensor.

3. The electronic nose device for gas composition analysis according to claim 1, characterized in that, The multiple sensors in the sensor array (2) inside the container are arranged in a star-shaped pattern, a planar matrix pattern, or a single column pattern.

4. The electronic nose device for gas composition analysis according to claim 1, characterized in that, The retractable container (1) is provided with an electromagnetic induction wireless charging module (9), which is used to charge the sensor array (2) inside the container and / or the sensor array (5) inside the airway.

5. The electronic nose device for gas composition analysis according to claim 1, characterized in that, It also includes a wireless communication module, which is connected to the in-container sensor array (2) and the in-airway sensor array (5) and is used to send out the data detected by the in-container sensor array (2) and the in-airway sensor array (5).

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