Pressure data compensation method based on temperature sensor and underground water level monitoring device

Abstract

The invention provides a pressure data compensation method based on a temperature sensor and an underground water level monitoring device, relates to the technical field of temperature compensation of pressure sensors, and aims to realize a pressure sensor capable of more reliably and efficiently coping with extremely cold weather. Real-time temperature data and real-time pressure data are obtained through a temperature sensor and a pressure sensor respectively; based on the fluctuation range coefficient and the real-time temperature data, obtaining the range of the corrected temperature; the compensated pressure range is obtained through the corrected temperature range and the real-time pressure data; and selecting an optimal pressure value from the compensated pressure range as a final compensated pressure value. The method has the advantage that the data detection accuracy of the pressure sensor in the extremely cold environment is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of temperature compensation of pressure sensors, and in particular to a pressure data compensation method based on a temperature sensor and a groundwater level monitoring device. Background Art

[0002] Pressure sensor is a common pressure data detection device with a wide range of applications.

[0003] However, in actual use, pressure sensors are often subjected to the test of the natural environment. For example, in high-altitude cold areas, especially in permafrost areas, the surface temperature is extremely low in winter, and the surface and shallow underground water bodies are prone to freezing. Currently commonly used groundwater level monitoring equipment mainly relies on pressure sensors to measure the pressure of the water body, and then inversely calculate the water level. When the water body freezes, its volume expansion will directly affect the pressure measurement results, resulting in data inaccuracy or equipment damage, affecting the accuracy and reliability of monitoring. Traditional solutions usually include simple anti-freeze designs, such as adding insulation layers or using electric heating devices. However, these methods are limited in effect when dealing with extremely cold environments, and are usually accompanied by problems such as high energy consumption and complex maintenance.

[0004] Therefore, it is necessary to design a pressure sensor that can cope with extremely cold weather more reliably and efficiently, and improve the data detection accuracy of the pressure sensor in extremely cold environments. Summary of the invention

[0005] The object of the present invention is to provide a pressure data compensation method and a groundwater level monitoring device based on a temperature sensor, which can cope with extremely cold weather more reliably and efficiently.

[0006] The present invention is achieved through the following technical solutions:

[0007] First, a pressure data compensation method based on a temperature sensor is provided, comprising the following steps:

[0008] Get the fluctuation range coefficient γ of the temperature sensor;

[0009] Acquire real-time temperature data and real-time pressure data through temperature sensors and pressure sensors respectively;

[0010] Based on the fluctuation range coefficient and the real-time temperature data, a range of the corrected temperature is obtained, T lb ,T ub are the lower and upper limits of the range of the corrected temperature, respectively;

[0011] The compensated pressure range, P, is obtained by using the corrected temperature range and the real-time pressure data. lb ,P ub are the lower and upper limits of the compensated pressure range respectively;

[0012] The best pressure value is selected from the compensated pressure range as the final compensated pressure value P fi .

[0013] Preferably, the method for obtaining the fluctuation range coefficient of the temperature sensor is:

[0014] Acquiring an accuracy influencing parameter ac of the temperature sensor, wherein the accuracy influencing parameter represents the influence of the sensor accuracy on the detection value;

[0015] Obtaining a short-term uniformity influence parameter ev of the temperature sensor, wherein the short-term uniformity influence parameter represents the influence of a sensor value change on a detection value within a certain period of time;

[0016] Get the fluctuation range coefficient γ of the temperature sensor:

[0017]

[0018] Preferably, the method for obtaining the accuracy influencing parameter ac is:

[0019]

[0020] sa=0.1 x ;

[0021] Among them, sa is the accuracy value of the temperature sensor, x is the number of decimal places of the detection value of the temperature sensor, and n is the adjustment constant.

[0022] Preferably, the method for obtaining the short-term uniformity impact parameter ev is:

[0023]

[0024] m∈[1,5];

[0025]

[0026] Wherein, ea is an intermediate parameter, m is the duration of short-term sampling of the detection value of the temperature sensor and the unit is seconds, N is the total number of short-term sampling of the detection value of the temperature sensor, te i is the detection value of the i-th temperature sensor sampled in a short period of time.

[0027] Preferably, the method for obtaining the range of the corrected temperature based on the fluctuation range coefficient and the real-time temperature data is:

[0028] T real ∈[T lb ,T ub ];

[0029] Tlb =(1-γ)*T measure ;

[0030] T ub =(1+γ)*T measure ;

[0031] Among them, T real is the corrected temperature, T measure is the real-time temperature data.

[0032] Preferably, the method for obtaining the compensated pressure range through the corrected temperature range and the real-time pressure data is:

[0033] P com ∈[P lb ,P ub ];

[0034] P lb =P measure *(1+θ*(T lb -T ref );

[0035] P ub =P measure *(1+θ*(T ub -T ref );

[0036] Among them, P com is the pressure after compensation, θ is the empirical compensation coefficient, T ref is the reference temperature, P measure is the real-time pressure data.

[0037] Preferably, the method of selecting the best pressure value from the compensated pressure range as the final compensated pressure value is:

[0038] Continuously acquiring measured values ​​of a total of J pressure sensors within s seconds;

[0039] Respectively obtaining the compensated pressure ranges of the measured values ​​of the J pressure sensors;

[0040] Taking the intersection of the compensated pressure ranges of the measured values ​​of the J pressure sensors;

[0041] The median of the intersection of the compensated pressure range is selected as the final compensated pressure value P fi .

[0042] The present invention also provides a groundwater level monitoring device, applying any one of the above-mentioned pressure data compensation methods based on a temperature sensor, comprising a pressure sensor and a temperature sensor;

[0043] Based on the temperature sensor, the real-time pressure data of the pressure sensor is compensated by the pressure data compensation method to obtain the final compensated pressure value;

[0044] The water level H is obtained based on the final compensated pressure value:

[0045]

[0046] Among them, ρ(T fi ) represents the temperature obtained by looking up the table as T fi is the water density at , and g is the acceleration due to gravity.

[0047] Preferably, the sensing chamber of the pressure sensor is filled with an isolation liquid, and a flexible diaphragm is provided between the isolation liquid and the water body. The isolation liquid is used to transfer the pressure of the water body to the sensing surface of the pressure sensor to prevent the pressure sensor from directly contacting the water body.

[0048] Preferably, the outer layer of the pressure sensor is wrapped with a thermal insulation material.

[0049] The technical solution of the present invention has at least the following advantages and beneficial effects:

[0050] The present invention can compensate for the pressure sensor data deviation caused by low temperature, thereby improving the accuracy of the detection data of the temperature sensor;

[0051] The present invention performs pressure compensation based on the temperature data of the temperature sensor. While processing the temperature data, the instability and accuracy limitations of the temperature sensor are also taken into account, thereby further improving the accuracy of pressure compensation.

[0052] The pressure sensor of the present invention can be easily applied to various devices that need to test pressure and has a wide range of applications;

[0053] The groundwater level monitoring device of the present invention can be applied to extremely cold environments to solve the problem of measurement data error caused by freezing of water under extremely low temperature conditions, ensuring that the monitoring device can provide accurate and stable data in harsh environments;

[0054] The invention has reasonable design, simple structure, easy implementation of relevant data processing and high cost performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0055] Figure 1 A schematic flow chart of a pressure data compensation method based on a temperature sensor provided in Example 1 of the present invention;

[0056] Figure 2 A schematic structural diagram of an example of providing an isolation liquid and a flexible diaphragm for a groundwater level monitoring device provided in Example 2 of the present invention;

[0057] Icon: 101-pressure sensor, 102-housing, 103-water body, 104-flexible diaphragm, 105-insulation material, 106-isolating liquid. DETAILED DESCRIPTION

[0058] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings here can be arranged and designed in various different configurations.

[0059] Example 1

[0060] This embodiment provides a pressure data compensation method based on a temperature sensor. Figure 1 , including the following steps:

[0061] Get the fluctuation range coefficient γ of the temperature sensor;

[0062] Acquire real-time temperature data and real-time pressure data through temperature sensors and pressure sensors respectively;

[0063] Based on the fluctuation range coefficient and the real-time temperature data, a range of the corrected temperature is obtained, T lb ,T ub are the lower and upper limits of the range of the corrected temperature, respectively;

[0064] The compensated pressure range, P, is obtained by using the corrected temperature range and the real-time pressure data. lb ,P ub are the lower and upper limits of the compensated pressure range respectively;

[0065] The best pressure value is selected from the compensated pressure range as the final compensated pressure value P fi .

[0066] In this embodiment, the method for obtaining the fluctuation range coefficient of the temperature sensor is:

[0067] Acquiring an accuracy influencing parameter ac of the temperature sensor, wherein the accuracy influencing parameter represents the influence of the sensor accuracy on the detection value;

[0068] Obtaining a short-term uniformity influence parameter ev of the temperature sensor, wherein the short-term uniformity influence parameter represents the influence of a sensor value change on a detection value within a certain period of time;

[0069] Get the fluctuation range coefficient γ of the temperature sensor:

[0070]

[0071] The fluctuation range coefficient represents the accuracy of the temperature sensor data. The larger the fluctuation range coefficient, the lower the accuracy of the temperature sensor. Therefore, a temperature value range will be taken into account around the actual detected value, that is, the larger the fluctuation range coefficient, the larger the temperature value range.

[0072] Furthermore, the method for obtaining the accuracy influencing parameter ac is:

[0073]

[0074] sa=0.1 x ;

[0075] Where sa is the accuracy value of the temperature sensor, x is the number of decimal places of the detection value of the temperature sensor, and n is the adjustment constant. In practical applications, n can be 2-3. For example, the number of decimal places of the detection value of the temperature sensor is 1 decimal place, that is, its accuracy can monitor -10.5 degrees. Here n is 2, then

[0076] On the other hand, the method for obtaining the short-term uniformity impact parameter ev is:

[0077]

[0078] m∈[1,5];

[0079]

[0080] Wherein, ea is an intermediate parameter, m is the duration of short-term sampling of the detection value of the temperature sensor and the unit is seconds, N is the total number of short-term sampling of the detection value of the temperature sensor, te i is the detection value of the i-th temperature sensor sampled in a short period of time.

[0081] It should be noted that the short-term uniformity influencing parameters are mainly obtained by continuous sampling in a short period of time. The stability of the sensor value is used to determine the possible error of the detection. The more unstable the short-term uniformity influencing parameters are, the larger the short-term uniformity influencing parameters will be, which means there will be a larger error. The final real-time temperature data acquisition correction temperature range will also be larger. m can be 2-5 seconds, and N can be 10-20 times. The calculation of the short-term uniformity influencing parameters does not need to be updated all the time. An update cycle can be set to detect, calculate and update the short-term uniformity influencing parameters of the temperature sensor and store them, and they can be directly applied each time the actual measurement is performed.

[0082] On this basis, the method for obtaining the range of the corrected temperature based on the fluctuation range coefficient and the real-time temperature data is:

[0083] T real ∈[T lb ,T ub ];

[0084] T lb =(1-γ)*T measure ;

[0085] T ub =(1+γ)*T measure ;

[0086] Among them, T real is the corrected temperature, T measure This step is to expand the range of the real-time temperature data according to the size of the fluctuation range. The previous calculation shows that the larger the fluctuation range, the greater the possible error of the temperature sensor.

[0087] Next, the method for obtaining the compensated pressure range through the corrected temperature range and the real-time pressure data is:

[0088] P com ∈[P lb ,P ub ];

[0089] P lb =P measure *(1+θ*(T lb -T ref );

[0090] P ub =P measure *(1+θ*(T ub -T ref );

[0091] Among them, P com is the pressure after compensation, θ is the empirical compensation coefficient, T ref is the reference temperature, P measure is the real-time pressure data.

[0092] Finally, the method of selecting the best pressure value from the compensated pressure range as the final compensated pressure value is:

[0093] Continuously acquiring measured values ​​of a total of J pressure sensors within s seconds;

[0094] Respectively obtaining the compensated pressure ranges of the measured values ​​of the J pressure sensors;

[0095] Taking the intersection of the compensated pressure ranges of the measured values ​​of the J pressure sensors;

[0096] The median of the intersection of the compensated pressure range is selected as the final compensated pressure value P fi . Continuously collect measured values ​​of multiple pressure sensors, select the common range of all measured values ​​in the compensated pressure range of all measured values, and exclude the non-common range, that is, the non-common range is regarded as having a large error. When executing specifically, s can be 2-10 seconds, and J can be 10-30.

[0097] Example 2

[0098] The present invention also provides a groundwater level monitoring device, applying any one of the above-mentioned pressure data compensation methods based on a temperature sensor, comprising a pressure sensor and a temperature sensor;

[0099] Based on the temperature sensor, the real-time pressure data of the pressure sensor is compensated by the pressure data compensation method to obtain the final compensated pressure value;

[0100] The water level H is obtained based on the final compensated pressure value:

[0101]

[0102] Among them, ρ(T fi ) represents the temperature obtained by looking up the table as T fi is the water density at , and g is the acceleration due to gravity.

[0103] In this embodiment, a case can be referred to Figure 2 The sensing chamber of the pressure sensor 101 is filled with an isolation liquid 106, and a flexible diaphragm 104 is arranged between the isolation liquid 106 and the water body 103. The isolation liquid 106 is used to transmit the pressure of the water body 103 to the sensing surface of the pressure sensor 101 to prevent the pressure sensor 101 from directly contacting the water body 103. The isolation liquid 106 can be made of silicone oil (such as -50°C antifreeze silicone oil). The flexible diaphragm 104 can be made of fluororubber, which has excellent low-temperature elasticity and pressure resistance, can still maintain good flexibility in an environment of -60°C, and can effectively transmit pressure.

[0104] Furthermore, the outer layer of the pressure sensor 101 is wrapped with a heat-insulating material 105. The main heat-insulating layer is a polyurethane foam with a thickness of 2 cm, and the thermal conductivity is lower than 0.025 W / m·K, which effectively isolates the external low temperature. The outer layer is further coated with a layer of aluminum foil heat-insulating film to reduce heat loss. The design of the heat-insulating material 105 can ensure that even at an extremely low temperature of -50°C, the temperature inside the pressure sensor 101 can still be maintained within a suitable working range, ensuring the stability of the measurement data.

[0105] In the specific implementation, a stainless steel pressure sensor 101, model PSS-316L, can be selected. This sensor has good corrosion resistance and low temperature resistance, and is suitable for long-term operation in a high-cold environment. The pressure sensor 101 has a measurement range of 0-2MPa, which can cover water level measurement in a water depth range of 0 to 20 meters. The resolution of the sensor is 0.1kPa, and the temperature operating range is -50℃ to 85℃.

[0106] On the other hand, the housing 102 of the device can be made of titanium alloy material. Titanium alloy has extremely high cold resistance and corrosion resistance, ensuring that the sensor can operate stably for a long time in harsh environments. In addition, the titanium alloy housing 102 also has high mechanical strength and can withstand the pressure of the external permafrost layer. The existence of the housing 102 will not affect the normal operation of the pressure sensor 101, because the sensor is in contact with the external water body 103 through the flexible diaphragm 104, and the pressure signal is transmitted to the isolation liquid 106 inside the sensor through the diaphragm, and then transmitted to the sensing surface of the sensor. Because the diaphragm has sufficient elasticity, it can deform freely under the protection of the housing 102, thereby ensuring the effective transmission of pressure.

[0107] When installing the groundwater level monitoring device, you can choose a reasonable installation depth based on the depth of the permafrost layer, the range of interannual changes, and the specific requirements of the monitoring target to ensure that the sensor avoids the seasonal frozen layer while not affecting the normal measurement of groundwater. You can also install it at an angle of 30-45 degrees. At this time, the vertical pressure of the frozen layer on the relevant sensors is greatly reduced, effectively reducing the measurement errors and equipment damage risks caused by freezing.

[0108] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A pressure data compensation method based on a temperature sensor, characterized in that: The following steps are involved: Get the fluctuation range coefficient γ of the temperature sensor; Acquire real-time temperature data and real-time pressure data through temperature sensors and pressure sensors respectively; Based on the fluctuation range coefficient and the real-time temperature data, a range of the corrected temperature is obtained, T lb ,T ub are the lower and upper limits of the range of the corrected temperature, respectively; The compensated pressure range, P, is obtained by using the corrected temperature range and the real-time pressure data. lb ,P ub are the lower and upper limits of the compensated pressure range respectively; The best pressure value is selected from the compensated pressure range as the final compensated pressure value P fi .

2. The pressure data compensation method based on temperature sensor according to claim 1, characterized in that: The method to obtain the fluctuation range coefficient of the temperature sensor is: Acquiring an accuracy influencing parameter ac of the temperature sensor, wherein the accuracy influencing parameter represents the influence of the sensor accuracy on the detection value; Obtaining a short-term uniformity influence parameter ev of the temperature sensor, wherein the short-term uniformity influence parameter represents the influence of a sensor value change on a detection value within a certain period of time; Get the fluctuation range coefficient γ of the temperature sensor:

3. The pressure data compensation method based on temperature sensor according to claim 2 is characterized in that: The method for obtaining the accuracy influencing parameter ac is: at=0.1 x ; Among them, sa is the accuracy value of the temperature sensor, x is the number of decimal places of the detection value of the temperature sensor, and n is the adjustment constant.

4. The pressure data compensation method based on temperature sensor according to claim 3 is characterized in that: The method for obtaining the short-term uniformity impact parameter ev is: m∈[1,5]； Wherein, ea is an intermediate parameter, m is the duration of short-term sampling of the detection value of the temperature sensor and the unit is seconds, N is the total number of short-term sampling of the detection value of the temperature sensor, te i is the detection value of the i-th temperature sensor sampled in a short period of time.

5. The pressure data compensation method based on temperature sensor according to claim 1, characterized in that: The method for obtaining the range of the corrected temperature based on the fluctuation range coefficient and the real-time temperature data is: T real ∈[T lb ,T ub ]; T lb =(1-γ)*T measure ; T ub =(1+γ)*T measure ; Among them, T real is the corrected temperature, T measure is the real-time temperature data.

6. The pressure data compensation method based on temperature sensor according to claim 5, characterized in that: The method for obtaining the compensated pressure range through the corrected temperature range and the real-time pressure data is: P com ∈[P lb ,P ub ]; Among them, P com For the pressure after compensation, is the empirical compensation coefficient, T ref is the reference temperature, P measure is the real-time pressure data.

7. The pressure data compensation method based on temperature sensor according to claim 1, characterized in that: The method of selecting the best pressure value from the compensated pressure range as the final compensated pressure value is: Continuously acquiring measured values ​​of a total of J pressure sensors within s seconds; Respectively obtaining the compensated pressure ranges of the measured values ​​of the J pressure sensors; Taking the intersection of the compensated pressure ranges of the measured values ​​of the J pressure sensors; The median of the intersection of the compensated pressure ranges is selected as the final compensated pressure value P fi .

8. A groundwater level monitoring device, using a pressure data compensation method based on a temperature sensor as claimed in any one of claims 1 to 7, characterized in that: Includes pressure sensor and temperature sensor; Based on the temperature sensor, the real-time pressure data of the pressure sensor is compensated by the pressure data compensation method to obtain the final compensated pressure value; The water level H is obtained based on the final compensated pressure value: Among them, ρ(T fi ) represents the temperature obtained by looking up the table as T fi is the water density at , and g is the acceleration due to gravity.

9. The underground water level monitoring device according to claim 8, characterized in that: The sensing chamber of the pressure sensor is filled with an isolation liquid, and a flexible diaphragm is arranged between the isolation liquid and the water body. The isolation liquid is used to transfer the pressure of the water body to the sensing surface of the pressure sensor to prevent the pressure sensor from directly contacting the water body.

10. The underground water level monitoring device according to claim 8, characterized in that: The outer layer of the pressure sensor is wrapped with a heat-insulating material.

Images