Test method for oxygen partial pressure of pressurized oxygen supply mask

Abstract

This invention discloses a method for testing the oxygen partial pressure of a pressurized oxygen supply mask. The pressurized oxygen supply mask is placed inside a sealed container. The data cable of the oxygen partial pressure sensor on the pressurized oxygen supply mask passes through the sealed container in a sealed manner. A vacuuming device and an oxygen supply device are connected to the outside of the sealed container. A temperature sensor for monitoring the internal temperature is installed on the sealed container. The sealed container is first evacuated and then filled with oxygen. The theoretical value of the oxygen partial pressure inside the sealed container is then calculated, and the corresponding phase value output by the oxygen partial pressure sensor is recorded. Then, the theoretical values ​​and phase values ​​of the oxygen partial pressure at different temperatures are collected, and the data is fitted to calibrate the parameters relating the measured value and the phase value of the oxygen partial pressure sensor. These parameters are then written into the oxygen partial pressure sensor. Finally, the theoretical value of the oxygen partial pressure is compared with the measured value of the oxygen partial pressure sensor to verify the accuracy of the oxygen partial pressure sensor. This method can accurately test the accuracy of the oxygen partial pressure sensor on a pressurized oxygen supply mask.

Description

Technical Field

[0001] This invention relates to pilot safety, specifically to a method for testing the partial pressure of oxygen in a pressurized oxygen supply mask. Background Technology

[0002] Pilots may encounter high-altitude hypoxia during missions. The most obvious impact of hypoxia is a decline in human-machine interface performance. In the early stages of hypoxia, it is often difficult for the pilot to detect. If there is no onboard equipment to monitor the pilot's oxygen supply status, the hypoxia will gradually worsen, leading to a severe decrease in human-machine interface performance and ultimately causing catastrophic accidents such as aircraft crashes and loss of life. Therefore, some pressurized oxygen masks integrate oxygen partial pressure sensors to monitor the pilot's oxygen supply status. However, currently there is no method to test the oxygen partial pressure of pressurized oxygen masks, making it difficult to guarantee the accuracy of the oxygen partial pressure sensors and consequently, the accuracy of oxygen supply status monitoring. Summary of the Invention

[0003] The purpose of this invention is to provide a method for testing the oxygen partial pressure of a pressurized oxygen supply mask, which fully considers the differences in oxygen supply status of the pressurized oxygen supply mask at different heights and temperatures, and can accurately test the oxygen partial pressure sensor on the pressurized oxygen supply mask.

[0004] The technical solution adopted in this invention is:

[0005] A method for testing the partial pressure of oxygen in a pressurized oxygen supply mask involves placing the mask inside a sealed container. The data cable of the oxygen partial pressure sensor on the mask is sealed and extends out of the container. The sealed container is connected to equipment for vacuuming and oxygen supply. A temperature sensor is installed on the container to monitor its internal temperature. The container is then evacuated and filled with oxygen. The theoretical partial pressure of oxygen inside the container is calculated, and the corresponding phase value output by the oxygen partial pressure sensor is recorded. Theoretical and phase values ​​of oxygen partial pressure at different temperatures are collected, and the data is fitted to calibrate the parameters relating the measured value and the phase value of the oxygen partial pressure sensor. These parameters are then written into the oxygen partial pressure sensor. Finally, the theoretical and measured values ​​of oxygen partial pressure are compared to verify the accuracy of the oxygen partial pressure sensor.

[0006] Preferably, when conducting oxygen partial pressure tests on pressurized oxygen masks, dedicated oxygen partial pressure testing software is used for calibrating the oxygen partial pressure sensor, writing parameters, verifying accuracy, and displaying and storing data; the oxygen partial pressure testing software includes:

[0007] The calibration subroutine is used to calculate the theoretical value of oxygen partial pressure and record the corresponding phase value output by the oxygen partial pressure sensor, collect the theoretical value and phase value of oxygen partial pressure at different temperatures, and fit the data to calibrate the parameters of the relationship between the measured value and the phase value of the oxygen partial pressure sensor.

[0008] The parameter writing subroutine is used to write the fitted parameters into the oxygen partial pressure sensor, and the oxygen partial pressure sensor calculates the measured value based on the parameters.

[0009] The accuracy verification subroutine is used to compare the theoretical value of oxygen partial pressure with the measured value of oxygen partial pressure sensor, thereby verifying the accuracy of oxygen partial pressure sensor;

[0010] The data display and storage subroutine is used to display the oxygen partial pressure time waveform, record all theoretical oxygen partial pressure values, oxygen partial pressure sensor measurements, temperature, and phase data, and provide real-time visualization of the data.

[0011] Furthermore, the calibration subroutine, parameter writing subroutine, accuracy verification subroutine, and data display and storage subroutine are independent of each other, and all transmit and read data through external interfaces.

[0012] Preferably, the relationship between the measured value, phase value, and temperature output by the oxygen partial pressure sensor is as follows:

[0013]

[0014] Where PO2 is the measured value output by the oxygen partial pressure sensor, θ is the phase value output by the oxygen partial pressure sensor, A, B, C, and D are temperature-related parameters, and T is the temperature, i.e., the output value of the temperature sensor.

[0015] When T > 10℃

[0016] A = a 11 T 2 +b 11 T+c 11

[0017] B = a 21 T 2 +b 21 T+c 21

[0018] C = a 31 T 2 +b 31 T+c 31

[0019] D = a 41 T 2 +b 41 T+c 41

[0020] When T≤10℃,

[0021] A = a 12 T 2 +b 12 T+c 12

[0022] B = a 22 T 2 +b 22 T+c 22

[0023] C = a 32 T 2 +b 32 T+c 32

[0024] D = a 42 T 2 +b 42 T+c 42

[0025] Among them, a 11 b 11 c 11 a 21 b 21 c 21 a 31 b 31 c 31 a 41 b 41 c 41 The data were derived from data fitting, using theoretical values ​​of oxygen partial pressure and phase values ​​at T > 10℃; a 12 b 12 c 12 a 22 b 22 c 22 a 32 b 32 c 32 a 42 b 42 c 42 The results were derived from data fitting, using theoretical values ​​of oxygen partial pressure and phase values ​​at T≤10℃.

[0026] Preferably, the theoretical value of the oxygen partial pressure inside the sealed container is calculated using the following formula:

[0027] Theoretical value of oxygen partial pressure = (p1-p2)*N

[0028] Wherein, P1 is the current pressure value, that is, the pressure value after the sealed container is evacuated and then filled with oxygen; P2 is the reference pressure value, that is, the pressure value after the sealed container is evacuated; N is the standard oxygen concentration for filling with oxygen.

[0029] Preferably, the range of P2 is -98kPa to -100kPa.

[0030] Preferably, the oxygen partial pressure sensor is considered to have normal accuracy if the difference between the theoretical value of oxygen partial pressure and the value of oxygen partial pressure sensor is within ±0.5 kPa.

[0031] The beneficial effects of this invention are:

[0032] This method fully considers the differences in oxygen supply status of pressurized oxygen masks at different altitudes and temperatures, and can accurately test the oxygen partial pressure sensor on the pressurized oxygen mask, thereby ensuring that the tested oxygen supply status of the pilot is the true state. This lays a solid foundation for the development of other models and has good military and market promotion benefits. Attached Figure Description

[0033] Figure 1 This is a schematic diagram of the equipment installation during the oxygen partial pressure test of the pressurized oxygen supply mask in an embodiment of the present invention.

[0034] Figure 2 This is a flowchart illustrating the calibration subroutine in an embodiment of the present invention.

[0035] Figure 3 This is a flowchart illustrating the parameter writing subroutine in an embodiment of the present invention.

[0036] Figure 4 This is a flowchart of the accuracy verification subroutine in an embodiment of the present invention.

[0037] Figure 5 This is a flowchart illustrating the data display and storage subroutine in an embodiment of the present invention.

[0038] Figure 6 This is the display interface of the data display and storage subroutine in this embodiment of the invention.

[0039] In the diagram: 1-Pressurized oxygen supply mask; 2-Flow switch; 3-Vacuum pump; 4-Oxygen cylinder; 5-Exhaust outlet; 6-Data acquisition and processing module; 7-Computer. Detailed Implementation

[0040] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. The components of the embodiments of this application described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0041] Therefore, the following detailed description of the embodiments of this application provided in the accompanying drawings is not intended to limit the scope of the claimed application, but merely to illustrate selected embodiments of the application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application.

[0042] The features and performance of this application will be further described in detail below with reference to the embodiments.

[0043] This embodiment discloses a method for testing the partial pressure of oxygen in a pressurized oxygen supply mask, such as... Figure 1 As shown, a pressurized oxygen mask is placed inside a sealed container. The data cable of the oxygen partial pressure sensor on the pressurized oxygen mask 1 passes through the sealed container in a sealed manner. The sealed container is connected to a device for vacuuming (e.g., a vacuum pump 3 with a flow switch 2) and a device for adding oxygen (e.g., an oxygen cylinder 4 with a flow switch 2). A temperature sensor for monitoring the internal temperature is installed on the sealed container. Figure 1 (Not shown in the text); then, first evacuate the sealed container and then fill it with oxygen, then calculate the theoretical value of the oxygen partial pressure inside the sealed container and record the corresponding phase value output by the oxygen partial pressure sensor; then collect the theoretical value and phase value of the oxygen partial pressure at different temperatures, then fit the data, calibrate the parameters of the relationship between the measured value and the phase value of the oxygen partial pressure sensor, and then write the parameters into the oxygen partial pressure sensor; then compare the theoretical value of the oxygen partial pressure with the measured value of the oxygen partial pressure sensor to verify the accuracy of the oxygen partial pressure sensor.

[0044] When conducting oxygen partial pressure tests on pressurized oxygen masks, to avoid cumbersome data processing, dedicated oxygen partial pressure testing software (such as...) can be used. Figure 1 As shown, the software installed on computer 7) is used for calibrating the oxygen partial pressure sensor, writing parameters, verifying accuracy, and displaying and storing data; the oxygen partial pressure testing software includes:

[0045] The calibration subroutine is used to calculate the theoretical value of oxygen partial pressure and record the corresponding phase value output by the oxygen partial pressure sensor, collect the theoretical value and phase value of oxygen partial pressure at different temperatures, and fit the data to calibrate the parameters of the relationship between the measured value and the phase value of the oxygen partial pressure sensor.

[0046] The parameter writing subroutine is used to write the fitted parameters into the oxygen partial pressure sensor, and the oxygen partial pressure sensor calculates the measured value based on the parameters.

[0047] The accuracy verification subroutine is used to compare the theoretical value of oxygen partial pressure with the measured value of oxygen partial pressure sensor, thereby verifying the accuracy of oxygen partial pressure sensor;

[0048] The data display and storage subroutine is used to display the oxygen partial pressure time waveform, record all theoretical oxygen partial pressure values, oxygen partial pressure sensor measurements, temperature, and phase data, and provide real-time visualization of the data.

[0049] The calibration subroutine, parameter writing subroutine, accuracy verification subroutine, and data display and storage subroutine are independent of each other, and all transmit and read data through an external interface (RS-485 / 422).

[0050] The relationship between the measured value, phase value, and temperature output by the oxygen partial pressure sensor is as follows:

[0051]

[0052] Where PO2 is the measured value output by the oxygen partial pressure sensor, θ is the phase value output by the oxygen partial pressure sensor, A, B, C, and D are temperature-related parameters, and T is the temperature, i.e., the output value of the temperature sensor.

[0053] When T > 10℃

[0054] A = a 11 T 2 +b 11 T+c 11

[0055] B = a 21 T 2 +b 21 T+c 21

[0056] C = a 31 T 2 +b 31 T+c 31

[0057] D = a 41 T 2 +b 41 T+c 41

[0058] When T≤10℃,

[0059] A = a 12 T 2 +b 12 T+c 12

[0060] B = a 22 T 2 +b 22 T+c 22

[0061] C = a 32 T 2 +b 32 T+c 32

[0062] D = a 42 T2 +b 42 T+c 42

[0063] Among them, a 11 b 11 c 11 a 21 b 21 c 21 a 31 b 31 c 31 a 41 b 41 c 41 The data were derived from data fitting, using theoretical values ​​of oxygen partial pressure and phase values ​​at T > 10℃; a 12 b 12 c 12 a 22 b 22 c 22 a 32 b 32 c 32 a 42 b 42 c 42 The results were derived from data fitting, using theoretical values ​​of oxygen partial pressure and phase values ​​at T≤10℃.

[0064] The theoretical formula for calculating the partial pressure of oxygen inside a sealed container is:

[0065] Theoretical value of oxygen partial pressure = (p1-p2)*N

[0066] Wherein, P1 is the current pressure value, that is, the pressure value after the sealed container is evacuated and then filled with oxygen; P2 is the reference pressure value, that is, the pressure value after the sealed container is evacuated; N is the standard oxygen concentration for filling with oxygen.

[0067] Preferably, the range of P2 is -98kPa to -100kPa.

[0068] Preferably, the oxygen partial pressure sensor is considered to have normal accuracy if the difference between the theoretical value of oxygen partial pressure and the value of oxygen partial pressure sensor is within ±0.5 kPa.

[0069] As can be seen from the above technical solution, this method fully considers the differences in oxygen supply status of the pressurized oxygen supply mask 1 at different altitudes and temperatures, and can accurately test the oxygen partial pressure sensor on the pressurized oxygen supply mask 1, thereby ensuring that the oxygen supply status of the pilot tested is the real state, laying a solid foundation for the development of other models, and having good military benefits and market promotion benefits.

[0070] The oxygen partial pressure testing software is described in detail below.

[0071] Calibration subroutine:

[0072] It mainly includes three modules: sensor parameter setting, sensor data display, and sensor data storage. The process is as follows: Figure 2 As shown: LabVIEW reads the vacuum value from the pressure gauge and calculates the theoretical value of the oxygen partial pressure. If the difference between the theoretical value of the oxygen partial pressure and the oxygen partial pressure sensor value is within ±0.5 kPa, it is considered normal; otherwise, it is considered abnormal. If abnormal, the oxygen concentration and pressure gauge value need to be readjusted until the current test requirements are met.

[0073] Table 1 Sensor Parameter List

[0074]

[0075] If the above sensor parameter data is empty or shows irregular fluctuations, it is abnormal. It is necessary to check the sensor settings and data transmission for any abnormalities.

[0076] If the sensor phase curve is not displayed or exhibits irregular fluctuations (a difference of more than 0.4 in amplitude between the upper and lower values ​​under normal temperature and pressure), it is abnormal. The sensor settings and data transmission should be checked for any abnormalities.

[0077] Parameter writing subroutine:

[0078] The parameter writing subroutine process is as follows: Figure 3 As shown: LabVIEW reads the PID settings, determines whether to enter the enable or disable path based on the conditions, writes commands according to the PID status of the protocol, and writes the enable / disable status to the sensor through the VISA write control; based on the PID enable status, when the PID enable is 1, writing parameters is not allowed, and the received communication data may not be returned; when the PID enable is 0, writing parameters is allowed, and the received data is returned after successful writing, and the entire communication command is returned.

[0079] Table 2 Sensor Parameter Setting Page Control Table

[0080]

[0081]

[0082] Precision verification subroutine:

[0083] The accuracy verification subroutine flow is as follows: Figure 4 As shown

[0084] Table 3. Oxygen Partial Pressure Measurement Accuracy

[0085]

[0086] The VISA reader control is used to read the serial port buffer data, and the valid character segments are parsed according to the protocol and converted into readable data. The oxygen partial pressure, temperature, and phase are packaged into clusters for unified display.

[0087] Table 4 Sensor Parameter List

[0088]

[0089] Data storage subroutine:

[0090] like Figure 5 As shown, the data display and storage subroutine is divided into three parts. The first part is the selection of the sensor serial port, which selects the corresponding serial port according to the actual situation. The second part is the display of sensor data, which displays the oxygen partial pressure data and the oxygen partial pressure curve over time. The third part is the data acquisition, which records and stores the acquired data in real time.

[0091] Reading serial port data: A conditional check is performed; if the serial port data is empty, an exception warning is issued. If the data is normal, valid character segments are parsed according to the protocol and converted into readable data. All data is packaged into clusters for unified display.

[0092] If the software interface (e.g.) Figure 6 If the oxygen partial pressure time curve (as shown) is not displayed or exhibits irregular fluctuations, it is abnormal. It is necessary to check whether there are any abnormalities in the sensor parameters and data transmission.

[0093] The embodiments described above are some, but not all, of the embodiments of this application. The detailed description of the embodiments of this application is not intended to limit the scope of the claimed application, but merely to illustrate selected embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application.

Claims

1. A method for testing the partial pressure of oxygen in a pressurized oxygen supply mask, characterized in that: Place the pressurized oxygen supply mask inside a sealed container. The data cable of the oxygen partial pressure sensor on the pressurized oxygen supply mask should be sealed and pass through the sealed container. Connect the sealed container to equipment for vacuuming and oxygen supply. Install a temperature sensor on the sealed container to monitor the internal temperature. First, evacuate the sealed container and then fill it with oxygen. Calculate the theoretical value of the oxygen partial pressure inside the sealed container and record the corresponding phase value output by the oxygen partial pressure sensor. Then, collect the theoretical values ​​and phase values ​​of the oxygen partial pressure at different temperatures, fit the data, calibrate the parameters relating the measured value and the phase value of the oxygen partial pressure sensor, and then write the parameters into the oxygen partial pressure sensor. Then, the theoretical value of oxygen partial pressure is compared with the measured value of oxygen partial pressure sensor to verify the accuracy of oxygen partial pressure sensor; When conducting oxygen partial pressure tests on pressurized oxygen supply masks, dedicated oxygen partial pressure testing software is provided for calibrating oxygen partial pressure sensors, writing parameters, verifying accuracy, and displaying and storing data. The oxygen partial pressure testing software includes: The calibration subroutine is used to calculate the theoretical value of oxygen partial pressure and record the corresponding phase value output by the oxygen partial pressure sensor, collect the theoretical value and phase value of oxygen partial pressure at different temperatures, and fit the data to calibrate the parameters of the relationship between the measured value and the phase value of the oxygen partial pressure sensor. The parameter writing subroutine is used to write the fitted parameters into the oxygen partial pressure sensor, and the oxygen partial pressure sensor calculates the measured value based on the parameters. The accuracy verification subroutine is used to compare the theoretical value of oxygen partial pressure with the measured value of oxygen partial pressure sensor, thereby verifying the accuracy of oxygen partial pressure sensor; The data display and storage subroutine is used to display the oxygen partial pressure time waveform, record all theoretical oxygen partial pressure values, oxygen partial pressure sensor measurements, temperature, and phase data, and provide real-time visualization of the data. The relationship between the measured value, phase value, and temperature output by the oxygen partial pressure sensor is as follows: in, This is the measured value output by the oxygen partial pressure sensor. This is the phase value output by the oxygen partial pressure sensor. A, B, C, D These are temperature-related parameters, let them be... T This refers to the temperature, specifically the output value of the temperature sensor. when T When >10℃, When T≤10℃, in, , , , , , , , , , , , They were derived from data fitting, and the data used were... T Theoretical values ​​and phase values ​​of oxygen partial pressure at >10℃; , , , , , , , , , , , The results were derived from data fitting, using theoretical values ​​of oxygen partial pressure and phase values ​​at T≤10℃.

2. The method for testing the oxygen partial pressure of a pressurized oxygen supply mask as described in claim 1, characterized in that: The calibration subroutine, parameter writing subroutine, accuracy verification subroutine, and data display and storage subroutine are independent of each other, and all of them transmit and read data through external interfaces.

3. The method for testing the oxygen partial pressure of a pressurized oxygen supply mask as described in claim 1, characterized in that: The theoretical formula for calculating the partial pressure of oxygen inside a sealed container is: Wherein, P1 is the current pressure value, that is, the pressure value after the sealed container is evacuated and then filled with oxygen; P2 is the reference pressure value, that is, the pressure value after the sealed container is evacuated; N is the standard oxygen concentration for filling with oxygen.

4. The method for testing the oxygen partial pressure of a pressurized oxygen supply mask as described in claim 3, characterized in that: The range of P2 is -98kPa to -100kPa.

5. The method for testing the oxygen partial pressure of a pressurized oxygen supply mask as described in claim 1, characterized in that: If the difference between the theoretical value of oxygen partial pressure and the value of the oxygen partial pressure sensor is within ±0.5 kPa, then the oxygen partial pressure sensor is of normal accuracy.

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