A high-reliability laser oxygen partial pressure detection device and its use method and correction method

Abstract

The present invention discloses a high-reliability laser oxygen partial pressure detection device and its use method and correction method. The detection device includes a main controller, to which at least one oxygen partial pressure sensor is connected. The detection device of the present invention can use multiple oxygen partial pressure sensors to measure oxygen concentration, which is beneficial to improving the reliability of the detection device. By simultaneously compensating for temperature and pressure, it is beneficial to improve the detection accuracy. It can not only effectively reduce the risk of temperature drift and time drift, but also effectively cope with harsh environments such as low pressure in space. It has the advantages of high precision and high reliability, and can work reliably for a long time in harsh environments such as space, which is of great significance for promoting its wide application in the aerospace field. Its use method has the advantages of simple operation and high accuracy, and by correcting the oxygen partial pressure value, a more accurate oxygen partial pressure value can be obtained, which is of great significance for accurately grasping the oxygen concentration in the detection environment.

Description

Technical Field

[0001] The invention belongs to the technical field of gas sensors and relates to a high-reliability laser oxygen partial pressure detection device and a use method and a correction method thereof. Background Art

[0002] At present, the devices for detecting oxygen content / oxygen concentration mainly include oxygen sensors based on electrochemical-zirconia technology and tunable semiconductor laser absorption spectroscopy (TDLAS) technology. Among them, the oxygen sensor based on electrochemical-zirconia technology has the disadvantages of short service life and large temperature drift; and the oxygen sensor based on tunable semiconductor laser absorption spectroscopy (TDLAS) technology (also called laser oxygen sensor) is mainly used to detect the oxygen concentration in the ground environment, lacking the measurement of oxygen partial pressure. At the same time, although it can overcome the disadvantages of large temperature drift and difficulty in calibration and calibration, it cannot make corresponding compensation according to the changes in temperature and pressure, so it is difficult to obtain accurate oxygen content / oxygen concentration. It can be seen that the existence of the above-mentioned disadvantages greatly limits the wide application of oxygen sensors.

[0003] In the field of aerospace, it is necessary to monitor the oxygen content / oxygen concentration in spacecraft (such as high-orbit aircraft), which plays a vital role in protecting the life and health of astronauts. However, for the outer space environment where the spacecraft is located, the air pressure is not the standard atmospheric pressure, and sometimes it may be low pressure or even ultra-low pressure. For example, at low pressure, if the oxygen concentration is measured directly, the measured value will be too large, so it is difficult to accurately grasp the oxygen content / oxygen concentration in the spacecraft. Therefore, using oxygen partial pressure as a measure of oxygen content / oxygen concentration in spacecraft (such as high-orbit aircraft) is more conducive to protecting the life and health of astronauts. In addition, spacecraft are easily affected by radiation in the outer space environment, which makes some key components very easy to fail, which is not conducive to timely and reliable acquisition of detection data. At the same time, in space, failed or damaged devices cannot be replaced in time, so the sensor needs to have higher reliability. Therefore, obtaining an oxygen partial pressure detection device with high precision and high reliability is of great significance to promoting its wide application in the aviation field. Summary of the invention

[0004] The technical problem to be solved by the present invention is to overcome the deficiencies of the prior art and provide a laser oxygen partial pressure detection device with high precision and high reliability, and a use method and a correction method thereof.

[0005] In order to solve the above technical problems, the technical solution adopted by the present invention is:

[0006] A high-reliability laser oxygen partial pressure detection device comprises a main controller, wherein the main controller is connected to at least one oxygen partial pressure sensor via an electrical connector;

[0007] The oxygen partial pressure sensor includes a microcontroller, and a DAC output port and an ADC input port are provided on the panel of the microcontroller, wherein the DAC output port is electrically connected to a signal superposition circuit, a V / I conversion circuit, a laser driver, and a laser in sequence; the signal superposition circuit is electrically connected to a bias voltage power supply; the laser is optically connected to an optical absorption cell and a laser detector in sequence; the optical absorption cell is connected to a temperature sensor and a pressure sensor; the laser detector is electrically connected to an I / V conversion circuit, a phase-locked amplifier, a filter amplifier circuit, and an ADC input port in sequence, for inputting a second harmonic signal into the microcontroller; a high-pass filter and a phase-shift frequency multiplication circuit are electrically connected between the V / I conversion circuit and the phase-locked amplifier, for inputting a reference signal into the phase-locked amplifier; the temperature sensor and the pressure sensor are electrically connected to the ADC input port, respectively, for inputting the temperature and pressure values ​​in the optical absorption cell into the microcontroller.

[0008] As a further improvement of the above technical solution: the number of the oxygen partial pressure sensors is 3.

[0009] As a further improvement of the above technical solution: the number of the DAC output port, the ADC input port, the laser, the laser detector, and the filter amplifier circuit in the oxygen partial pressure sensor is at least 2.

[0010] As a further improvement of the above technical solution: the laser is electrically connected to a temperature control circuit; the number of the temperature control circuits is at least 2; the laser is a 763nm VCSEL laser; and the temperature control circuit is a TEC temperature control circuit.

[0011] As a further improvement of the above technical solution: the optical absorption cell is arranged in the environment to be detected; the optical absorption cell is a White cell.

[0012] As a general technical concept, the present invention also provides a method for using the above-mentioned high-reliability laser oxygen partial pressure detection device, which uses an oxygen partial pressure sensor to obtain an oxygen partial pressure value, comprising the following steps:

[0013] S1. Check whether the second harmonic peak value is normal; if not, send an error message and end the test; if normal, proceed to the next step;

[0014] S2. Obtaining the oxygen concentration value in the optical absorption cell according to the second harmonic peak value obtained in step S1;

[0015] S3. Using a temperature sensor and a pressure sensor to obtain the temperature and pressure values ​​in the optical absorption cell, combined with the oxygen concentration value obtained in step S2, the temperature and pressure values ​​are synchronously compensated according to the least squares fitting method to obtain the oxygen partial pressure values ​​at different temperatures and pressures.

[0016] As a further improvement of the above technical solution: in S1, when the number of the DAC output port, the ADC input port, the laser, the laser detector, and the filter amplifier circuit in the oxygen partial pressure sensor is 2, and the second harmonic peak value detected by one of the parallel detection routes is abnormal, the following processing is also included: starting another parallel detection route and detecting whether the second harmonic peak value generated by it is normal in the same way.

[0017] As a further improvement of the above technical solution: the method of use also includes the following processing: using the oxygen partial pressure sensor to continuously collect oxygen partial pressure values ​​and continuously monitor the environment to be detected.

[0018] As a general technical concept, the present invention also provides a correction method for a high-reliability laser oxygen partial pressure detection device, which corrects the oxygen partial pressure value obtained in the above-mentioned method of use, comprising the following steps:

[0019] The main controller is used to read the oxygen partial pressure values ​​measured by different oxygen partial pressure sensors to determine whether the oxygen partial pressure sensor reports an error; if an error occurs in the oxygen partial pressure sensor, the oxygen partial pressure value corresponding to the oxygen partial pressure sensor reporting the error is abandoned; if the oxygen partial pressure sensor transmits data normally, the oxygen partial pressure values ​​corresponding to different oxygen partial pressure sensors are stored in the main controller;

[0020] According to the oxygen partial pressure values ​​corresponding to different oxygen partial pressure sensors stored in the main controller, their average value is taken as the corrected oxygen partial pressure value.

[0021] As a further improvement of the above technical solution: when the number of the oxygen partial pressure sensors is 3, the average value is obtained by the following method:

[0022] (2.1) The oxygen partial pressure values ​​corresponding to the three oxygen partial pressure sensors stored in the main controller are allocated and recorded as QA, QB, and QC in sequence. If one of the oxygen partial pressure sensors does not have a corresponding oxygen partial pressure value, it is replaced by the corresponding oxygen partial pressure value of another oxygen partial pressure sensor, and so on;

[0023] (2.2) Determine whether QA, QB, and QC are assigned with oxygen partial pressure values; if QA, QB, and QC are all assigned with oxygen partial pressure values, and the difference between any two oxygen partial pressure values ​​is ≤1 kPa, then the average of these three oxygen partial pressure values ​​is used as the corrected oxygen partial pressure value; or, if QA, QB, and QC are all assigned with oxygen partial pressure values, and the difference between any two oxygen partial pressure values ​​is greater than 1 kPa, then the average of the two closest oxygen partial pressure values ​​is selected as the corrected oxygen partial pressure value; if there are only two oxygen partial pressure values ​​among QA, QB, and QC, then the average of these two oxygen partial pressure values ​​is used as the corrected oxygen partial pressure value; if there is only one oxygen partial pressure value among QA, QB, and QC, then this group of oxygen partial pressure values ​​is used as the corrected oxygen partial pressure value.

[0024] Compared with the prior art, the advantages of the present invention are:

[0025] (1) Aiming at the defects of low accuracy and poor reliability of existing oxygen sensors, the present invention creatively proposes a laser oxygen partial pressure detection device, which includes at least one oxygen partial pressure sensor. When one of the sensors has temperature drift, the other sensors can continue to measure the oxygen concentration, which is beneficial to improve the reliability of the detection device. At the same time, the oxygen partial pressure sensor is also connected to the optical absorption cell, so that the temperature and pressure can be compensated at the same time, and a more accurate oxygen partial pressure value can be obtained under a wider temperature and pressure range, so that the adverse effects of temperature or pressure changes on the detection accuracy can be effectively reduced, and the detection device shows very high detection accuracy. The laser oxygen partial pressure detection device of the present invention adopts a multi-redundant design, and multiple oxygen partial pressure sensors can measure the oxygen concentration at the same time, which can not only effectively reduce the risk of temperature drift and time drift, but also effectively cope with the harsh environment such as low pressure in space through temperature and pressure compensation. It has the advantages of high accuracy and high reliability, and can maintain very high reliability in harsh environments such as space, thereby ensuring that related products can work reliably for a long time in harsh environments such as space, which is of great significance for promoting its wide application in the aerospace field.

[0026] (2) In the laser oxygen partial pressure detection device of the present invention, a dual redundant design is adopted for the key circuits of the oxygen partial pressure sensor, which is beneficial to avoid sensor failure due to failure of a certain component, and is also beneficial to improving the reliability and accuracy of the detection device.

[0027] (3) The present invention also provides a method for using a laser oxygen partial pressure detection device, which uses an oxygen partial pressure sensor to obtain an oxygen partial pressure value. The second harmonic signal is first obtained through tunable semiconductor laser absorption spectroscopy technology to obtain the oxygen concentration. Then, based on the temperature and pressure obtained from the temperature sensor and the pressure sensor, the temperature and pressure are simultaneously compensated using a least squares fitting method, thereby achieving the measurement of the oxygen partial pressure value. The device has the advantages of simple operation and high accuracy.

[0028] (4) The present invention also provides a correction method for a laser oxygen partial pressure detection device, first using a main controller to read the oxygen partial pressure values ​​measured by different oxygen partial pressure sensors, and taking their average value as the corrected oxygen partial pressure value according to the oxygen partial pressure values ​​corresponding to the different oxygen partial pressure sensors stored in the main controller. In particular, when the number of oxygen partial pressure sensors is 3, the average value is obtained by the following method: the oxygen partial pressure values ​​corresponding to the 3 oxygen partial pressure sensors stored in the main controller are distributed and recorded as Q A , Q B , Q CIf one of the oxygen partial pressure sensors does not have a corresponding oxygen partial pressure value, it will be replaced by the corresponding oxygen partial pressure value of another oxygen partial pressure sensor, and so on. A , Q B , Q C Is there an oxygen partial pressure value assigned in Q A , Q B , Q C If the oxygen partial pressure values ​​are evenly distributed and the difference between any two oxygen partial pressure values ​​is ≤1kPa, the average of these three oxygen partial pressure values ​​is used as the corrected oxygen partial pressure value. A , Q B , Q C When the oxygen partial pressure values ​​are evenly distributed and the difference between two oxygen partial pressure values ​​is greater than 1 kPa, the average of the two groups of oxygen partial pressure values ​​that are closer is selected as the corrected oxygen partial pressure value; if Q A , Q B , Q C If there are only two sets of oxygen partial pressure values, the average of these two sets of oxygen partial pressure values ​​is used as the corrected oxygen partial pressure value; if Q A , Q B , Q C If there is only one set of oxygen partial pressure values, this set of oxygen partial pressure values ​​is used as the corrected oxygen partial pressure values. In the present invention, by correcting the obtained oxygen partial pressure values, a more accurate oxygen partial pressure value can be obtained, which is of great significance for accurately grasping the oxygen concentration in the detection environment. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In order to make the purpose, technical solution and advantages of the embodiments of the present invention more clear, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention.

[0030] Figure 1 It is a structural schematic diagram of the laser oxygen partial pressure detection device in the present invention.

[0031] Figure 2 This is a detection principle diagram of the oxygen partial pressure sensor in the present invention.

[0032] Figure 3 The figure is a schematic diagram of the use process of the laser oxygen partial pressure detection device in the present invention.

[0033] Figure 4 It is a schematic diagram of the correction process of the laser oxygen partial pressure detection device in the present invention.

[0034] Legend:

[0035] 1. Microcontroller; 101. DAC output port; 102. ADC input port; 2. Signal superposition circuit; 3. Bias voltage power supply; 4. V / I conversion circuit; 5. Laser driver; 6. Laser; 601. Temperature control circuit; 7. Optical absorption cell; 8. Temperature sensor; 9. Pressure sensor; 10. Laser detector; 11. I / V conversion circuit; 12. Phase-locked amplifier; 13. Filter amplifier circuit; 14. High-pass filter; 15. Phase shift and frequency multiplication circuit; a. Reference signal; b. Second harmonic signal. DETAILED DESCRIPTION

[0036] The present invention is further described below in conjunction with the accompanying drawings and specific preferred embodiments, but the protection scope of the present invention is not limited thereby.

[0037] Example

[0038] Existing oxygen sensors only measure the oxygen concentration in the ground environment, lack the measurement of oxygen partial pressure, and have low reliability requirements, so they cannot be used in the aerospace field. Moreover, these oxygen sensors only compensate for temperature alone, and do not compensate for temperature and pressure at the same time. Therefore, when the pressure in the environment changes, it is difficult to obtain accurate oxygen concentration data. In view of the defects of low accuracy and poor reliability of the above-mentioned existing oxygen sensors, the present invention creatively proposes a laser oxygen partial pressure detection device, which includes at least one oxygen partial pressure sensor. When one of the sensors has temperature drift, other sensors can continue to measure the oxygen concentration, which is beneficial to improve the reliability of the detection device; at the same time, the oxygen partial pressure sensor is also connected to the optical absorption cell with a temperature sensor and a pressure sensor, so that temperature and pressure can be compensated at the same time, and more accurate oxygen partial pressure values ​​can be obtained under a wider temperature and pressure range, thereby effectively reducing the adverse effects of temperature or pressure changes on detection accuracy, thereby making the detection device show very high detection accuracy. The laser oxygen partial pressure detection device of the present invention adopts a multi-redundancy design, and multiple oxygen partial pressure sensors can measure the oxygen concentration at the same time, which can not only effectively reduce the risk of temperature drift and time drift, but also effectively cope with harsh environments such as low pressure in space through temperature and pressure compensation. It has the advantages of high precision and high reliability, and can maintain very high reliability in harsh environments such as space, thereby ensuring that related products can work reliably for a long time in harsh environments such as space, which is of great significance for promoting its wide application in the aviation field.

[0039] In order to better understand the innovation of the technical solution of the present invention, as one of the examples in the technical solution of the present invention, Figure 1As shown, the high reliability laser oxygen partial pressure detection device of this embodiment includes a main controller, which is connected to at least one oxygen partial pressure sensor through an electrical connector, wherein the oxygen partial pressure sensor includes a microcontroller 1, a DAC output port 101 and an ADC input port 102 are provided on a panel of the microcontroller 1, the DAC output port 101 is electrically connected to a signal superposition circuit 2, a V / I conversion circuit 4, a laser driver 5, and a laser 6 in sequence; the signal superposition circuit 2 is electrically connected to a bias voltage power supply 3; the laser 6 is optically connected to an optical absorption cell 7 and a laser detector 10 in sequence; the optical absorption cell 7 is electrically connected to a bias voltage power supply 3; the laser 6 is optically connected to an optical absorption cell 7 and a laser detector 10 in sequence; A temperature sensor 8 and a pressure sensor 9 are connected; the laser detector 10 is electrically connected to an I / V conversion circuit 11, a phase-locked amplifier 12, a filter amplifier circuit 13, and an ADC input port 102 in sequence, for inputting a second harmonic signal into the microcontroller 1; a high-pass filter 14 and a phase-shift frequency multiplication circuit 15 are electrically connected between the V / I conversion circuit 4 and the phase-locked amplifier 12, for inputting a reference signal into the phase-locked amplifier 12; the temperature sensor 8 and the pressure sensor 9 are electrically connected to the ADC input port 102, respectively, for inputting the temperature and pressure values ​​in the optical absorption cell 7 into the microcontroller 1.

[0040] In this embodiment, the number of oxygen partial pressure sensors is 3.

[0041] In this embodiment, the number of the DAC output port 101, the ADC input port 102, the laser 6, the laser detector 10, and the filter amplifier circuit 13 in the oxygen partial pressure sensor is two.

[0042] In this embodiment, a temperature control circuit 601 is electrically connected to the laser 6; the number of the temperature control circuits 601 is 2; the laser 6 is a 763nm VCSEL laser; and the temperature control circuit 601 is a TEC temperature control circuit.

[0043] In this embodiment, the optical absorption cell 7 is arranged in the environment to be detected; the optical absorption cell 7 is a White cell.

[0044] In this embodiment, the main controller is a computer.

[0045] In the present invention, the oxygen partial pressure sensor used is a laser oxygen partial pressure sensor proposed based on TDLAS technology, such as Figure 2As shown in the figure, the detection principle is as follows: the two DAC ports DAC1 and DAC2 of the microcontroller generate superposition signals of high-frequency sine waves and low-frequency triangular waves respectively. DAC1 channel 1 is the main channel and DAC2 is the backup channel. When DAC channel 1 fails or is disordered, channel 2 is enabled to ensure the reliability of the sensor. The bias voltage 2.5V (bias voltage power supply) adjusts the scanning range of the triangular wave through the signal superposition circuit to ensure that the absorption peak is within the scanning range. The V / I conversion circuit converts the voltage into a current signal and transmits it to the laser driver driving current, and drives one of the 763nmVCSEL lasers through the two-choice module. In order to prevent the 763nmVCSEL laser from working for a long time and causing the light intensity to weaken, resulting in offset, two 763nmVCSE lasers are used, laser 1 is the main laser, and laser 2 is the backup laser to ensure the reliability of the oxygen partial pressure sensor. Both lasers are equipped with TEC temperature control circuit 1 and TEC temperature control circuit 2 for temperature control. Laser 1 and laser 2 are collimated and incident into the optical absorption pool, specifically, multiple reflections are performed in the White pool to increase the optical path. In the optical absorption cell, a temperature sensor and a pressure sensor are installed to monitor the temperature and pressure of the optical absorption cell, and the microcontroller performs temperature and pressure compensation according to the temperature and pressure values. Detectors 1 and 2 detect the optical signals of laser 1 and laser 2 respectively, and convert the optical signals into current signals. The I / V conversion circuit converts the current signal into a voltage signal and transmits it to the phase-locked amplifier. Since the phase-locked amplifier requires a reference signal a, the laser drive signal is passed through a high-pass filter to obtain a high-frequency sine wave, and then the phase and frequency multiplication are adjusted by the phase shifting and frequency multiplication circuit to provide a reference signal. The high-frequency signal is filtered out by the filter amplifier circuit 1 and the filter amplifier circuit 2 to obtain the second harmonic signal b, and the microcontroller collects the second harmonic signal through the ADC1 and ADC2 ports. In order to improve the reliability of the oxygen partial pressure test, the oxygen partial pressure sensor adopts a triple redundant design. The main controller collects the values ​​of the three oxygen partial pressure sensors through the electrical connector, and performs data processing and analysis to obtain the final oxygen partial pressure value. At the same time, the key circuits of the oxygen partial pressure sensor adopt a dual redundant design, which is conducive to avoiding sensor failure due to failure of a certain component, and is also conducive to improving the reliability and accuracy of the detection device. The total radiation resistance of the selected chips is greater than 10Krad (Si), which improves the anti-interference performance.

[0046] Furthermore, a method for using the high reliability laser oxygen partial pressure detection device in the above embodiment is also provided, such as Figure 3 As shown, obtaining the oxygen partial pressure value using the oxygen partial pressure sensor includes the following steps:

[0047] S1. Detect whether the generated second harmonic peak is normal; if not, send an error message and end the detection; if normal, execute the next step; in the present invention, if the basic shape of the second harmonic can be detected and its peak is within a certain range, it is normal.

[0048] S2, obtaining the oxygen concentration value in the optical absorption cell 7 according to the second harmonic peak value obtained in step S1;

[0049] S3. Use the temperature sensor 8 and the pressure sensor 9 to obtain the temperature and pressure values ​​in the optical absorption cell 7, and combine them with the oxygen concentration value obtained in step S2, and synchronously compensate the temperature and pressure values ​​according to the least squares fitting method to obtain the oxygen partial pressure values ​​under different temperatures and pressures.

[0050] In this embodiment, in S1, when the number of the DAC output port 101, the ADC input port 102, the laser 6, the laser detector 10, and the filter amplifier circuit 13 in the oxygen partial pressure sensor is 2, and the second harmonic peak value detected by one of the parallel detection routes is abnormal, the following processing is also included: starting another parallel detection route and detecting whether the second harmonic peak value generated by it is normal in the same way.

[0051] In this embodiment, the method of use also includes the following processing: using the oxygen partial pressure sensor to continuously collect oxygen partial pressure values ​​and continuously monitor the environment to be detected.

[0052] In the present invention, the system is first initialized, and then a low-frequency triangular wave and a high-frequency sine wave are generated and superimposed respectively, and DAC channel 1 is turned on, and the DAC channel 1 is output, and the ADC collects the signal of the second harmonic, and determines whether the peak-to-peak value of the second harmonic is within the normal range. If the peak-to-peak value is within the normal range, the oxygen concentration is calculated according to the peak-to-peak value; if the output peak-to-peak value is not within the normal range, the DA1 channel is closed, the superimposed sine wave and triangular wave are output through the DAC2 channel, the laser 2 is driven, and the ADC2 is turned on to collect the data of the second harmonic. If the peak-to-peak value of the second harmonic is within the normal range, the measured oxygen concentration is calculated; if the peak-to-peak value of the collected second harmonic is not within the normal range, an error message is sent to the host computer (main controller). After calculating the oxygen concentration, the values ​​of the temperature sensor and the pressure sensor are obtained, and the obtained values ​​are compensated for temperature and pressure. The temperature and pressure compensation method adopts the least squares fitting method to synchronously compensate for the temperature and pressure values, rather than simply compensating for the temperature value or the pressure value. After compensation by this method, the oxygen partial pressure at different temperatures and pressures can be measured. After temperature and pressure compensation, the value of the oxygen partial pressure is calculated and transmitted to the main controller. Re-loop the steps after ADC1 collects data and continuously monitors the oxygen partial pressure value.

[0053] Furthermore, a correction method for the high reliability laser oxygen partial pressure detection device in the above embodiment is also provided, such as Figure 4 As shown, the obtained oxygen partial pressure value is corrected, including the following steps:

[0054] (1) Using the main controller to read the oxygen partial pressure values ​​measured by different oxygen partial pressure sensors, determine whether the oxygen partial pressure sensor reports an error; if the oxygen partial pressure sensor reports an error, abandon the oxygen partial pressure value corresponding to the oxygen partial pressure sensor reporting the error; if the oxygen partial pressure sensor transmits data normally, store the oxygen partial pressure values ​​corresponding to the different oxygen partial pressure sensors in the main controller;

[0055] (2) According to the oxygen partial pressure values ​​corresponding to different oxygen partial pressure sensors stored in the main controller, their average value is taken as the corrected oxygen partial pressure value.

[0056] In this embodiment, when the number of oxygen partial pressure sensors is 3, the corrected oxygen partial pressure value is obtained by the following method:

[0057] (2.1) The oxygen partial pressure values ​​corresponding to the three oxygen partial pressure sensors (oxygen partial pressure sensor 1, oxygen partial pressure sensor 2, and oxygen partial pressure sensor 3) stored in the main controller are allocated and recorded as QA, QB, and QC in sequence. If one of the oxygen partial pressure sensors does not have a corresponding oxygen partial pressure value, it is replaced by the corresponding oxygen partial pressure value of another oxygen partial pressure sensor, and so on;

[0058] (2.2) Determine whether QA, QB, and QC are assigned with oxygen partial pressure values; if QA, QB, and QC are all assigned with oxygen partial pressure values, and the difference between each two oxygen partial pressure values ​​is ≤1kPa, then the average value of these three oxygen partial pressure values ​​is used as the corrected oxygen partial pressure value, or, if QA, QB, and QC are all assigned with oxygen partial pressure values, and there is a difference of >1kPa between two oxygen partial pressure values, then the average value of two groups of oxygen partial pressure values ​​that are closer is selected as the corrected oxygen partial pressure value; if there are only two groups of oxygen partial pressure values ​​in QA, QB, and QC, then the average value of these two groups of oxygen partial pressure values ​​is used as the corrected oxygen partial pressure value; if there is only one group of oxygen partial pressure values ​​in QA, QB, and QC, then this group of oxygen partial pressure values ​​is used as the corrected oxygen partial pressure value. In the present invention, measures are taken to prevent single-particle locking and single-particle flipping to increase its reliability.

[0059] The above embodiments are only preferred implementations of the present invention, and the protection scope of the present invention is not limited to the above embodiments. All technical solutions under the concept of the present invention belong to the protection scope of the present invention. It should be pointed out that for ordinary technicians in this technical field, improvements and modifications without departing from the principle of the present invention should also be regarded as the protection scope of the present invention.

Claims

1. A high reliability laser oxygen partial pressure detection device, characterized in that: comprising a main controller connected to at least one oxygen partial pressure sensor via an electrical connector; The oxygen partial pressure sensor comprises a microcontroller (1). A DAC output port (101) and an ADC input port (102) are provided on a panel of the microcontroller (1). The DAC output port (101) is electrically connected to a signal superposition circuit (2), a V / I conversion circuit (4), a laser driver (5), and a laser (6) in sequence; the signal superposition circuit (2) is electrically connected to a bias voltage power supply (3); the laser (6) is optically connected to an optical absorption cell (7) and a laser detector (10) in sequence; the optical absorption cell (7) is connected to a temperature sensor (8) and a pressure sensor (9); the laser detector (10) is electrically connected to an I / V conversion circuit (11), a phase-locked amplifier (12), a filter amplifier circuit (13), and an ADC input port (102) in sequence, and is used to input a second harmonic into the microcontroller (1). signal, and obtaining the oxygen concentration value in the optical absorption cell according to the obtained second harmonic peak value; a high-pass filter (14) and a phase-shift frequency multiplication circuit (15) are electrically connected between the V / I conversion circuit (4) and the phase-locked amplifier (12), and are used to input a reference signal into the phase-locked amplifier (12); the temperature sensor (8) and the pressure sensor (9) are respectively electrically connected to the ADC input port (102), and are used to input the temperature and pressure values ​​in the optical absorption cell (7) into the microcontroller (1); the temperature sensor (8) and the pressure sensor (9) are used to obtain the temperature and pressure values ​​in the optical absorption cell (7), and the temperature and pressure values ​​are synchronously compensated according to the least squares fitting method in combination with the oxygen concentration value, so as to obtain the oxygen partial pressure values ​​at different temperatures and pressures; the optical absorption cell (7) is arranged in the environment to be detected; and the optical absorption cell (7) is a White cell.

2. The high reliability laser oxygen partial pressure detection device according to claim 1, characterized in that: The number of the oxygen partial pressure sensors is 3.

3. The high reliability laser oxygen partial pressure detection device according to claim 1 or 2, characterized in that: The number of the DAC output port (101), the ADC input port (102), the laser (6), the laser detector (10), and the filter amplifier circuit (13) in the oxygen partial pressure sensor is at least 2.

4. The high reliability laser oxygen partial pressure detection device according to claim 3, characterized in that: The laser (6) is electrically connected to a temperature control circuit (601); the number of the temperature control circuits (601) is at least two; the laser (6) is a 763nm VCSEL laser; and the temperature control circuit (601) is a TEC temperature control circuit.

5. A method for using the high reliability laser oxygen partial pressure detection device according to any one of claims 1 to 4, characterized in that: Using the oxygen partial pressure sensor to obtain the oxygen partial pressure value includes the following steps: S1. Check whether the second harmonic peak value is normal; if not, send an error message and end the test; if normal, proceed to the next step; S2, obtaining the oxygen concentration value in the optical absorption cell (7) according to the second harmonic peak value obtained in step S1; S3. Using a temperature sensor (8) and a pressure sensor (9) to obtain the temperature and pressure values ​​in the optical absorption cell (7), and combining the oxygen concentration value obtained in step S2, the temperature and pressure values ​​are synchronously compensated according to a least squares fitting method to obtain oxygen partial pressure values ​​at different temperatures and pressures.

6. The method of use according to claim 5, characterized in that: In the above S1, when the number of the DAC output port (101), the ADC input port (102), the laser (6), the laser detector (10), and the filter amplifier circuit (13) in the oxygen partial pressure sensor is 2, and the second harmonic peak value detected by one of the parallel detection routes is abnormal, the following processing is also included: starting another parallel detection route and detecting whether the second harmonic peak value generated by it is normal in the same way.

7. The method of use according to claim 5 or 6, characterized in that: The method of use also includes the following processing: using an oxygen partial pressure sensor to continuously collect oxygen partial pressure values ​​and continuously monitor the environment to be detected.

8. A correction method for a high-reliability laser oxygen partial pressure detection device, characterized in that: Correcting the oxygen partial pressure value obtained in the method of use according to any one of claims 5 to 7 comprises the following steps: (1) Using the main controller to read the oxygen partial pressure values ​​measured by different oxygen partial pressure sensors, determine whether the oxygen partial pressure sensor reports an error; if the oxygen partial pressure sensor reports an error, abandon the oxygen partial pressure value corresponding to the oxygen partial pressure sensor reporting the error; if the oxygen partial pressure sensor transmits data normally, store the oxygen partial pressure values ​​corresponding to the different oxygen partial pressure sensors in the main controller; (2) Based on the oxygen partial pressure values ​​corresponding to different oxygen partial pressure sensors stored in the main controller, take their average value as the corrected oxygen partial pressure value.

9. The correction method according to claim 8, characterized in that: When the number of the oxygen partial pressure sensors is 3, the average value is obtained by the following method: (2.1) Allocate the oxygen partial pressure values ​​corresponding to the three oxygen partial pressure sensors stored in the main controller, and record them as QA, QB, and QC in sequence. If one of the oxygen partial pressure sensors does not have a corresponding oxygen partial pressure value, it is replaced by the corresponding oxygen partial pressure value of another oxygen partial pressure sensor, and so on; (2.2) Determine whether QA, QB, and QC are assigned with oxygen partial pressure values; if QA, QB, and QC are all assigned with oxygen partial pressure values, and the difference between any two oxygen partial pressure values ​​is ≤1 kPa, then the average of these three oxygen partial pressure values ​​is used as the corrected oxygen partial pressure value; or, if QA, QB, and QC are all assigned with oxygen partial pressure values, and the difference between any two oxygen partial pressure values ​​is greater than 1 kPa, then the average of the two closest oxygen partial pressure values ​​is selected as the corrected oxygen partial pressure value; if there are only two oxygen partial pressure values ​​in QA, QB, and QC, then the average of these two oxygen partial pressure values ​​is used as the corrected oxygen partial pressure value; if there is only one oxygen partial pressure value in QA, QB, and QC, then this one oxygen partial pressure value is used as the corrected oxygen partial pressure value.

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