Oxygen sensor based on charge pump electrochemical detection principle and detection method

Abstract

The application relates to an oxygen sensor and a detection method based on an electrochemical detection principle of a charge pump, and belongs to the technical field of sensors.The oxygen sensor comprises a gas detection module and a host module, and the gas detection module and the host module realize real-time data interaction through a data bus; the oxygen sensor comprises a gas detection module and a host module, and the gas detection module and the host module realize real-time data interaction through a data bus; the gas detection module is used for collecting environmental parameters and oxygen parameters, and converts the collected data into digital signals, which are transmitted to the host module through a digital bus; the host module is used for calculating accurate oxygen concentration information under an environmental state in real time according to the obtained environmental parameters and oxygen parameter digital signals. On the basis of reasonable adaptation of hardware and software, multi-dimensional information sensing and preprocessing are realized, and the detection precision of the oxygen sensor and the environmental adaptability of the oxygen sensor can be improved.

Description

Technical Field

[0001] This invention belongs to the field of sensor technology and relates to an oxygen sensor and detection method based on the charge pump electrochemical detection principle. Background Technology

[0002] Oxygen sensors, as crucial instruments for monitoring oxygen concentration in coal mines, play a vital role in early fire warning and disaster emergency response, and are currently the most mature and widely used fire early warning monitoring method. After more than a decade of development, electrochemical oxygen gas detection sensors based on liquid electrolytes offer high resolution and a wide detection range, representing the main technical principle of coal mine oxygen sensors. However, these liquid electrolyte-based electrochemical sensing elements produce water during the chemical reaction process. Over time, this causes the internal volume of the element to increase, leading to leakage and significantly reducing its lifespan or causing malfunction. This results in unstable oxygen sensor operation. Furthermore, irregular changes in airflow pressure in underground coal mine roadways can also lead to inaccurate monitoring data and false alarms. Therefore, fluorescence quenching detection, laser detection, and charge pump detection principles, which offer better detection performance, have become the research directions for next-generation oxygen gas detection technologies.

[0003] Currently, oxygen sensors based on the fluorescence quenching principle have been designed in the industrial detection field. However, they cannot adapt to the high dust and high humidity environment of underground coal mines and lack the basic technical conditions for developing intrinsically safe instruments for mining. Oxygen sensors based on laser detection technology are constrained by factors such as laser customization, optical structure design, and cost, and there are currently no engineering prototypes with application value. Currently, oxygen sensors from various manufacturers use electrochemical oxygen gas sensing elements based on liquid electrolytes to detect ambient oxygen concentration. When the humidity in the environment is high, the sensing element is prone to absorbing water and leakage. When there are sudden changes in atmospheric pressure or temperature, the sensor's detection value will change accordingly, easily leading to false alarms. This seriously affects the effectiveness of coal mine safety monitoring systems and impacts safe production in coal mines. Summary of the Invention

[0004] In view of this, the purpose of this invention is to provide an oxygen sensor and detection method based on the charge pump detection principle. Addressing the problems of leakage, short lifespan, and poor adaptability to the underground coal mine environment caused by chemical reactions in liquid electrolyte-based electrochemical oxygen gas sensing elements during operation, this invention employs a charge pump-based sensing element for oxygen gas detection. By using uninterrupted low-power real-time signal processing technology, the sensor's power-on preparation time is significantly reduced, and its lifespan is increased by more than three times. Simultaneously, by using an adaptive gas selection diaphragm, cross-interference from gases such as carbon dioxide and nitrogen oxides in the mine is reduced. Furthermore, the gas detection module design enables three-dimensional real-time monitoring of oxygen concentration, temperature, and atmospheric pressure, greatly improving the environmental adaptability of the oxygen sensor and the accuracy of measurement data, thus solving the common industry problem of low measurement accuracy of oxygen sensors in underground coal mines.

[0005] To achieve the above objectives, the present invention provides the following technical solution:

[0006] On the one hand, the present invention provides an oxygen sensor based on the charge pump electrochemical detection principle, including a gas detection module and a host module, wherein the gas detection module and the host module realize real-time data interaction through a data bus;

[0007] The gas detection module is used to collect environmental parameters and oxygen parameters, and convert the collected data into digital signals, which are then transmitted to the host module via a digital bus.

[0008] The host module is used to calculate and obtain accurate oxygen concentration information under environmental conditions in real time based on the acquired environmental parameters and oxygen parameter values.

[0009] Furthermore, the gas detection module includes an oxygen sensing element, a microprocessor, an oxygen signal processing circuit, an atmospheric pressure signal processing circuit, a temperature signal processing circuit, a continuous low-power signal real-time holding circuit, an adaptive gas selection diaphragm, and a housing.

[0010] The adaptive gas selection membrane is used to filter cross-gas components;

[0011] The oxygen sensing element and oxygen signal processing circuit are used to detect oxygen concentration.

[0012] The atmospheric pressure signal processing circuit is used to detect atmospheric pressure.

[0013] The temperature signal processing circuit is used to detect the ambient temperature.

[0014] The microprocessor is used to control the operation of each circuit, collect oxygen concentration ρ1, atmospheric pressure and ambient temperature data, and convert them into raw data types that can be recognized by the sensor and transmit them to the host module microprocessor.

[0015] The uninterrupted low-power signal real-time holding circuit adopts an adaptive real-time dynamic switching technology between battery and external power supply to keep the oxygen signal processing circuit running continuously with low power consumption.

[0016] Furthermore, the host module includes a microprocessor, a display circuit, a voltage conversion circuit, a communication circuit, a gas module communication interface circuit, a remote control receiving circuit, and an audible and visual alarm control circuit.

[0017] The microprocessor is used to calculate the temperature influence factor δ, the atmospheric pressure change rate factor ν, and the atmospheric pressure influence factor θ based on the collected oxygen concentration ρ1, atmospheric pressure, and ambient temperature, respectively; and based on the temperature influence factor δ, the atmospheric pressure change rate factor ν, and the atmospheric pressure influence factor θ, firstly, based on the atmospheric pressure change rate factor ν, to determine and update the processed oxygen concentration value ρ2, and then calculate the actual oxygen concentration value ρ based on the temperature influence factor δ and the atmospheric pressure influence factor θ.

[0018] The display circuit is used for real-time concentration display and human-computer interaction;

[0019] The voltage conversion circuit is used to convert external input voltage into high-precision, low-ripple internal circuitry.

[0020] The communication circuit is used to transmit real-time measurement data to the host computer via a standard protocol.

[0021] The gas module communication interface circuit is used to connect to the gas module and obtain real-time digital information on environmental parameters and oxygen parameters.

[0022] The remote control receiving circuit is used for receiving and processing remote control signals;

[0023] The audible and visual alarm control circuit is used to implement audible and visual alarm warnings when the detected value exceeds the limit.

[0024] On the other hand, the present invention provides a detection method for an oxygen sensor based on the charge pump electrochemical detection principle, comprising the following steps:

[0025] S1: Adaptive gas selection membrane filters out most of the cross-component gas components;

[0026] S2: Real-time collection of filtered oxygen concentration, atmospheric pressure, and ambient temperature;

[0027] S3: Calculate the temperature influence factor δ, the atmospheric pressure change rate factor ν, and the atmospheric pressure influence factor θ;

[0028] S4: Calculate the oxygen concentration processing value ρ2 using the oxygen filter function based on the atmospheric pressure change rate factor ν;

[0029] S5: Calculate the true oxygen concentration ρ under the current environment based on the temperature influence factor δ and the atmospheric pressure influence factor θ.

[0030] Furthermore, the temperature influence factor δ is calculated in the following way:

[0031] δ=t / k1

[0032] Where t is the actual temperature value and k1 is a constant value.

[0033] Furthermore, the atmospheric pressure change rate factor ν is calculated in the following manner:

[0034] ν=(p2–p1) / (s2–s1)

[0035] Where p2 is the atmospheric pressure value at time s2, and p1 is the atmospheric pressure value at time s1.

[0036] Furthermore, the atmospheric pressure influence factor θ is calculated in the following way:

[0037] θ=p / k2

[0038] Where: p is the actual atmospheric pressure value, and k2 is a constant value.

[0039] Furthermore, the oxygen concentration processing value ρ2 in step S4 is determined based on the following conditions and calculated from the following conditions based on the atmospheric pressure change rate factor ν:

[0040] (1) When 0.95≤ν≤1.05, ρ2=ρ1;

[0041] (2) When ν>1.05, set a time constant T, and after a time length of ν*T, update the data ρ2=ρ1;

[0042] (3) When ν < 0.95, set a time constant T, and after a time length of T / ν, update the data ρ2 = ρ1;

[0043] Where ρ1 is the sampled oxygen concentration value, and ρ2 is the oxygen concentration value after atmospheric pressure trend judgment.

[0044] Furthermore, the actual oxygen concentration ρ mentioned in step S5 is calculated by the following formula:

[0045] ρ=ρ2+ρ2*δ+ρ2*θ

[0046] Where: ρ2 is the oxygen concentration value after judging the atmospheric pressure trend, θ is the atmospheric pressure influence factor, and δ is the temperature influence factor.

[0047] The beneficial effects of this invention are as follows: Based on the reasonable adaptation of hardware and software, this invention realizes multi-dimensional information perception and preprocessing, which can improve the detection accuracy of oxygen sensors and the environmental adaptability of oxygen sensors.

[0048] Other advantages, objectives, and features of the invention will be set forth in part in the description which follows, and in part will be apparent to those skilled in the art from the following examination, or may be learned from practice of the invention. The objectives and other advantages of the invention can be realized and obtained through the following description. Attached Figure Description

[0049] To make the objectives, technical solutions, and advantages of the present invention clearer, the preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings, wherein:

[0050] Figure 1 This is a structural diagram of an oxygen sensor based on the charge pump detection principle;

[0051] Figure 2 Electrical schematic diagram of the sensor;

[0052] Figure 3 Electrical schematic diagram of oxygen gas detection module;

[0053] Figure 4 This is a flowchart of the sensor detection method.

[0054] Attached reference numerals: 1-Handle, 2-Outer shell, 3-Coal Mine Safety Sign, 4-Front Nameplate, 5-Buzzer, 6-Display Window, 7-Rear Nameplate, 8-Rear Cover, 9-Gas Chamber. Detailed Implementation

[0055] The following specific examples illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and various details in this specification can be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that the illustrations provided in the following embodiments are only schematic representations of the basic concept of the present invention. Unless otherwise specified, the following embodiments and features can be combined with each other.

[0056] The accompanying drawings are for illustrative purposes only and are schematic diagrams, not actual pictures. They should not be construed as limiting the invention. To better illustrate the embodiments of the invention, some parts in the drawings may be omitted, enlarged, or reduced, and do not represent the actual product dimensions. It is understandable to those skilled in the art that some well-known structures and their descriptions may be omitted in the drawings.

[0057] In the accompanying drawings of the embodiments of the present invention, the same or similar reference numerals correspond to the same or similar components. In the description of the present invention, it should be understood that if terms such as "upper," "lower," "left," "right," "front," and "rear" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, they are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, the terms used to describe positional relationships in the drawings are only for illustrative purposes and should not be construed as limiting the present invention. For those skilled in the art, the specific meaning of the above terms can be understood according to the specific circumstances.

[0058] Please see Figures 1-3 This invention provides an oxygen sensor based on the charge pump electrochemical detection principle, comprising a gas detection module and a host module. The gas detection module includes an oxygen sensing element, a microprocessor, an oxygen signal processing circuit, an atmospheric pressure signal processing circuit, a temperature signal processing circuit, a continuous low-power signal real-time holding circuit, an adaptive gas selection diaphragm, and a housing. The host module includes a microprocessor, a display circuit, a voltage conversion circuit, a communication circuit, a gas module communication interface circuit, a remote control receiving circuit, and an audible and visual alarm control circuit.

[0059] The outer casing 2 is equipped with a handle 1 and a coal safety sign 3. The front of the outer casing 2 is equipped with a front nameplate 4, a buzzer 5 and a display window 6. The rear is equipped with a rear cover 8, and the rear nameplate 7 is installed on the rear cover 8. The outer casing of the gas detection module is also equipped with a gas chamber 9.

[0060] To improve the accuracy of oxygen concentration measurement in underground coal mines, an adaptive gas selection diaphragm is first used to filter out most of the cross-component gases, such as carbon dioxide and nitrogen oxides. Secondly, changes in ambient temperature and atmospheric pressure significantly affect the detection accuracy of oxygen sensors. This approach breaks through the conventional one-dimensional oxygen concentration detection method by acquiring multi-source, multi-dimensional sensing variables of oxygen concentration, temperature, and atmospheric pressure in real time. The temperature influence factor δ, the atmospheric pressure change rate factor ν, and the atmospheric pressure influence factor θ are calculated. The temperature influence factor δ is calculated as follows: δ = t / k1, where t is the actual temperature value and k1 is a constant value (generally taken as 25). The atmospheric pressure change rate factor ν is calculated as follows: ν = (p2 – p1) / (s2 – s1), where p2 is the atmospheric pressure value at time s2 and p1 is the atmospheric pressure value at time s1. The atmospheric pressure influence factor θ is calculated as follows: θ = p / k2, where p is the actual atmospheric pressure value and k2 is a constant value (generally taken as 98.00).

[0061] A three-dimensional information real-time fusion preprocessing method is adopted. Different oxygen filtering functions are used for different atmospheric pressure change rate factors ν to calculate the oxygen concentration processing value ρ2. The oxygen concentration processing value ρ2 is determined based on the following conditions and calculated from the following conditions based on the atmospheric pressure change rate factor ν:

[0062] (1) When 0.95≤ν≤1.05, ρ2=ρ1;

[0063] (2) When ν>1.05, set a time constant T (usually 30), and after a time length of ν*T, update the data ρ2=ρ1;

[0064] (3) When ν < 0.95, set a time constant T (usually 30), and update the data ρ2 = ρ1 after a time length of T / ν;

[0065] Where ρ1 is the sampled oxygen concentration value, and ρ2 is the oxygen concentration value after atmospheric pressure trend judgment.

[0066] Next, based on the different temperature influence factors δ and atmospheric pressure influence factors θ, the true oxygen concentration ρ under the current environment is calculated by the following formula: ρ=ρ2+ρ2*δ+ρ2*θ, where: ρ2 is the oxygen concentration value after judging the atmospheric pressure trend, θ is the atmospheric pressure influence factor, and δ is the temperature influence factor.

[0067] If any variable in the function, such as the temperature influence factor δ, the atmospheric pressure change rate factor ν, or the atmospheric pressure influence factor θ, is not equal to 1, then the original oxygen concentration value ρ1 will not be equal to the true concentration value ρ. This indicates that after real-time fusion and preprocessing of multi-dimensional information, the measurement accuracy of oxygen concentration can be corrected and improved. Finally, an adaptive real-time dynamic switching technology between battery and external power supply is adopted to keep the oxygen signal processing circuit running continuously with low power consumption, keeping the oxygen sensing element always in an active state, thus achieving the goal of high-precision detection of oxygen sensor as soon as it is powered on.

[0068] Those skilled in the art will understand that all or part of the steps in the methods of the above embodiments can be implemented by a program instructing related hardware. The program can be stored in a computer-readable storage medium. When the program is executed, it can implement the steps of the method. The storage medium may be, for example, ROM / RAM, magnetic disk, optical disk, etc.

[0069] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. An oxygen sensor based on the charge pump electrochemical detection principle, characterized in that: It includes a gas detection module and a host module. The gas detection module interacts with the host module in real time via a data bus. The gas detection module is used to collect environmental parameters and oxygen parameters, and convert the collected data into digital signals, which are then transmitted to the host module via a digital bus. The host module is used to calculate and obtain accurate oxygen concentration information under environmental conditions in real time based on the acquired environmental parameters and oxygen parameter digital values. The host module includes a microprocessor, a display circuit, a voltage conversion circuit, a communication circuit, a gas module communication interface circuit, a remote control receiving circuit, and an audible and visual alarm control circuit. The microprocessor is used to calculate the temperature influence factor δ, the atmospheric pressure change rate factor ν, and the atmospheric pressure influence factor θ based on the collected oxygen concentration ρ1, atmospheric pressure, and ambient temperature, respectively; and based on the temperature influence factor δ, the atmospheric pressure change rate factor ν, and the atmospheric pressure influence factor θ, firstly, based on the atmospheric pressure change rate factor ν, to determine and update the processed oxygen concentration value ρ2, and then calculate the actual oxygen concentration value ρ based on the temperature influence factor δ and the atmospheric pressure influence factor θ. The display circuit is used for real-time concentration display and human-computer interaction; The voltage conversion circuit is used to convert external input voltage into high-precision, low-ripple internal circuitry. The communication circuit is used to transmit real-time measurement data to the host computer via a standard protocol. The gas module communication interface circuit is used to connect to the gas module and obtain real-time digital information on environmental parameters and oxygen parameters. The remote control receiving circuit is used for receiving and processing remote control signals; The audible and visual alarm control circuit is used to implement audible and visual alarm warnings when the detected value exceeds the limit. The temperature influence factor δ is calculated in the following way: δ = t / k1 Where t is the actual temperature value, and k1=25; The atmospheric pressure change rate factor ν is calculated in the following way: ν = (p2 – p1) / (s2 – s1) Where: p2 is the atmospheric pressure value at time s2, and p1 is the atmospheric pressure value at time s1; The atmospheric pressure influence factor θ is calculated in the following way: θ = p / k2 Where: p is the actual atmospheric pressure value, k2=98.00; The oxygen concentration treatment value ρ2 is determined based on the following conditions and calculated from the following conditions based on the atmospheric pressure change rate factor ν: (1) When 0.95≤ν≤1.05, ρ2 = ρ1; (2) When v > 1.05, set a time constant T, T = 30, after a time length, update data p2 = p1; p2 = p1; (3) When ν < 0.95, set a time constant T, T = 30, and update the data ρ2 = ρ1 after a time length of T / ν; Where ρ1 is the sampled oxygen concentration value, and ρ2 is the oxygen concentration value after atmospheric pressure trend judgment; The actual oxygen concentration ρ is calculated by the following formula: Where: ρ2 is the oxygen concentration value after judging the atmospheric pressure trend, θ is the atmospheric pressure influence factor, and δ is the temperature influence factor.

2. The oxygen sensor based on the charge pump electrochemical detection principle according to claim 1, characterized in that: The gas detection module includes an oxygen sensing element, a microprocessor, an oxygen signal processing circuit, an atmospheric pressure signal processing circuit, a temperature signal processing circuit, a continuous low-power signal real-time holding circuit, an adaptive gas selection diaphragm, and a housing. The adaptive gas selection membrane is used to filter cross-gas components; The oxygen sensing element and oxygen signal processing circuit are used to detect oxygen concentration. The atmospheric pressure signal processing circuit is used to detect atmospheric pressure. The temperature signal processing circuit is used to detect the ambient temperature. The microprocessor is used to control the operation of each circuit, collect oxygen concentration ρ1, atmospheric pressure and ambient temperature data, and convert them into raw data types that can be recognized by the sensor and transmit them to the host module microprocessor. The uninterrupted low-power signal real-time holding circuit adopts an adaptive real-time dynamic switching technology between battery and external power supply to keep the oxygen signal processing circuit running continuously with low power consumption.

3. A detection method of an oxygen sensor based on the charge pump electrochemical detection principle, characterized in that: Includes the following steps: S1: Adaptive gas selection membrane filters out most of the cross-component gas components; S2: Real-time collection of filtered oxygen concentration, atmospheric pressure, and ambient temperature; S3: Calculate the temperature influence factor δ, the atmospheric pressure change rate factor ν, and the atmospheric pressure influence factor θ; The temperature influence factor δ is calculated in the following way: δ = t / k1 Where t is the actual temperature value, and k1=25; The atmospheric pressure change rate factor ν is calculated in the following way: ν = (p2 – p1) / (s2 – s1) Where: p2 is the atmospheric pressure value at time s2, and p1 is the atmospheric pressure value at time s1; The atmospheric pressure influence factor θ is calculated in the following way: θ = p / k2 Where: p is the actual atmospheric pressure value, k2=98.00; S4: Based on the atmospheric pressure change rate factor ν, the oxygen concentration processing value ρ2 is calculated using an oxygen filter function; the oxygen concentration processing value ρ2 is determined according to the following conditions and calculated based on the atmospheric pressure change rate factor ν using the following conditions: (1) When 0.95≤ν≤1.05, ρ2 = ρ1; (2) When v > 1.05, set a time constant T, T = 30, after a time length, update data p2 = p1; p2 = p1; (3) When ν < 0.95, set a time constant T, T = 30, and update the data ρ2 = ρ1 after a time length of T / ν; Where ρ1 is the sampled oxygen concentration value, and ρ2 is the oxygen concentration value after atmospheric pressure trend judgment; S5: Calculate the true oxygen concentration ρ under the current environment based on the temperature influence factor δ and the atmospheric pressure influence factor θ; the true oxygen concentration ρ is calculated by the following formula: Where: ρ2 is the oxygen concentration value after judging the atmospheric pressure trend, θ is the atmospheric pressure influence factor, and δ is the temperature influence factor.

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