Dual-temperature compensation pressure sensor and temperature compensation method

Abstract

The invention relates to a dual-temperature-compensation pressure sensor, and the sensor comprises a sensor body which comprises a pressure sensing element and a first temperature sensor, and the pressure sensing element is used for sensing the pressure P and outputting a voltage signal Up; the first temperature sensor is used for sensing the temperature T1 of a medium and outputting a voltage signal UT1. The second temperature sensor is used for sensing the temperature T2 of the surrounding environment and outputting a voltage signal UT2; and the compensation module adjusts and compensates the pressure value Up detected by the pressure sensing element by adopting a compensation algorithm according to the temperature change detected by the temperature sensor I and the temperature sensor II, and finally obtains a corrected pressure value P '. According to the invention, through the detected temperature change, the compensation module is adopted to adjust the pressure reading in real time, so that the influence of the temperature on the pressure measurement is eliminated or reduced, and the measurement precision and stability under different temperature conditions are improved.

Description

Technical Field

[0001] The present invention relates to the field of sensor technology, and in particular to a dual-temperature-compensated pressure sensor and a temperature compensation method. Background Art

[0002] In the technical field of liquefied natural gas (LNG) tank trucks, it is crucial to accurately monitor and control the pressure and temperature of the medium inside the vehicle. With the application of Internet of Things technology in the monitoring system of LNG tank trucks, accurate measurement of pressure and temperature has become particularly critical. The accurate measurement of these parameters is directly related to the safe operation of the tank truck and the efficiency of logistics distribution.

[0003] However, the diffused silicon pressure sensor widely used in the market has certain limitations in the measurement process. This principle of pressure sensor is very sensitive to changes in ambient temperature, and its measurement accuracy is easily disturbed by temperature fluctuations. In the actual operating environment of LNG tank trucks, the medium temperature is usually maintained at an extremely low level, while the ambient temperature may fluctuate in a large range. Therefore, a pressure sensor that can effectively compensate for the influence of medium temperature and ambient temperature changes on pressure measurement accuracy is needed to solve the problems in the prior art. Summary of the invention

[0004] To this end, the technical problem to be solved by the present invention is to overcome the deficiencies in the prior art and provide a dual temperature compensated pressure sensor and a temperature compensation method. By detecting changes in ambient temperature and medium temperature, a compensation module is used to adjust the pressure reading to eliminate or reduce the influence of temperature on pressure measurement, thereby improving the measurement accuracy and stability under different temperature conditions. This can solve the problem that the medium temperature is low and the ambient temperature changes greatly during the use of LNG tank trucks, which has a relatively large impact on the measurement accuracy of the diffused silicon principle pressure transmitter.

[0005] In order to solve the above technical problems, the present invention provides a dual temperature compensated pressure sensor, comprising: The sensor body includes a pressure-sensitive element and a temperature sensor. The pressure-sensitive element is used to sense pressure P and output a voltage signal U. p The temperature sensor is used to sense the temperature T1 of the medium and output a voltage signal U T1 ; Temperature sensor 2, the temperature sensor 2 is used to sense the temperature T2 of the surrounding environment and output a voltage signal U T2 ; The compensation module uses a compensation algorithm to compensate the pressure value U detected by the pressure sensing element according to the temperature change detected by the temperature sensor 1 and the temperature sensor 2. p Adjust and compensate, and finally obtain the corrected pressure value P'.

[0006] In one embodiment of the present invention, the compensation module includes a signal conditioning module, a microprocessor, a D / A conversion module and a communication module. The voltage signals of the pressure-sensitive element, temperature sensor 1 and temperature sensor 2 are amplified, filtered and conditioned by the signal conditioning module and then transmitted to the microprocessor. The microprocessor outputs the processed results as a corrected pressure value through the D / A conversion module.

[0007] In one embodiment of the present invention, the compensation algorithm in the compensation module uses a BP neural network to adjust the pressure compensation value according to real-time temperature changes.

[0008] In one embodiment of the present invention, the BP neural network includes an input layer, at least one hidden layer and an output layer. The input layer receives the voltage signal output by the pressure-sensitive element and the temperature-sensitive element, the hidden layer is used to process the data transmitted from the input layer, and the output layer is used to output the predicted pressure value.

[0009] In one embodiment of the present invention, the sensor body is made of a low-temperature resistant sapphire chip.

[0010] In one embodiment of the present invention, the pressure sensing element is a diffused silicon pressure sensor.

[0011] In one embodiment of the present invention, the temperature sensor 1 and the temperature sensor 2 are both made of semiconductor thermistor material.

[0012] In the second aspect, in order to solve the above technical problems, the present invention discloses a temperature compensation method, the specific method is as follows: S1. Input training samples, test samples and ideal output samples; S2. Normalize the sample data to obtain a training set; S3. Set network parameters and build BP neural network; S4. Set the number of iterations, target error, and use the measured sample data to train and test the BP neural network; S5. Output model structure coefficients; S6. Input the test samples into the trained model and return the results to the integrated processing before output.

[0013] The above technical solution of the present invention has the following beneficial effects compared with the prior art: The dual temperature compensated pressure sensor described in the present invention has the advantages of high precision, high stability, low temperature coefficient and low drift; by detecting the changes in ambient temperature and medium temperature, a compensation module is used to adjust the pressure reading to eliminate or reduce the influence of temperature on pressure measurement, thereby improving the measurement accuracy and stability under different temperature conditions, and can effectively solve the problem of low medium temperature and large ambient temperature changes during the use of LNG tank trucks, which have a relatively large impact on the measurement accuracy of the diffused silicon principle pressure transmitter. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] In order to make the contents of the present invention more clearly understood, the present invention is further described in detail below based on specific embodiments of the present invention in conjunction with the accompanying drawings.

[0015] Figure 1 It is a schematic diagram of the structure of a dual temperature compensated pressure sensor for an LNG tank truck in a preferred embodiment of the present invention; Figure 2 yes Figure 1 The temperature compensation principle of the dual temperature compensation pressure sensor of the LNG tank truck shown in the figure; Figure 3 yes Figure 1 The flowchart of the BP neural network for constructing the dual temperature compensated pressure sensor of the LNG tank truck shown; Figure 4 is the predicted pressure value before temperature compensation of the dual temperature compensated pressure sensor of the LNG tank truck in the present invention; Figure 5 It is the predicted pressure value after temperature compensation of the dual temperature compensated pressure sensor of the LNG tank truck in the present invention. DETAILED DESCRIPTION

[0016] The present invention is further described below in conjunction with the accompanying drawings and specific embodiments so that those skilled in the art can better understand the present invention and implement it, but the embodiments are not intended to limit the present invention. Embodiment 1

[0017] Reference Figure 1 As shown, a dual temperature compensated pressure sensor of the present invention comprises: The sensor body includes a pressure-sensitive element and a temperature sensor. The pressure-sensitive element is used to sense pressure P and output a voltage signal U. p The temperature sensor is used to sense the temperature T1 of the medium and output a voltage signal U T1 ; Temperature sensor 2, the temperature sensor 2 is used to sense the temperature T2 of the surrounding environment and output a voltage signal U T2 ; The compensation module uses a compensation algorithm to compensate the pressure value U detected by the pressure sensing element according to the temperature change detected by the temperature sensor 1 and the temperature sensor 2. p Adjustment and compensation are performed, and finally the corrected pressure value P′ is obtained to eliminate or reduce the influence of temperature change on pressure measurement.

[0018] The compensation module in this embodiment includes a signal conditioning module, a microprocessor, a D / A conversion module and a communication module. The voltage signals of the pressure-sensitive element, temperature sensor 1 and temperature sensor 2 are amplified, filtered and conditioned by the signal conditioning module and then transmitted to the microprocessor. The microprocessor outputs the processed results through the D / A conversion module to the corrected pressure value P.

[0019] Furthermore, the compensation algorithm in the compensation module uses a BP neural network to adjust the pressure compensation value according to the real-time temperature change. The compensation module can automatically adjust the pressure compensation value according to the real-time temperature change to achieve an ideal measurement effect. This automatic adjustment capability enables the pressure sensor to maintain high accuracy in a dynamically changing environment, and by using the compensation module to automatically adjust the pressure compensation value, the number of electronic components of the pressure sensor itself is reduced, which helps to enhance the seismic resistance of the pressure sensor and reduce the impact of vibration on the life and stability of the product.

[0020] Preferably, the BP neural network includes an input layer, at least one hidden layer and an output layer, the input layer receives the voltage signal output by the pressure-sensitive element and the temperature-sensitive element, the hidden layer is used to process the data transmitted from the input layer, and the output layer is used to output the predicted pressure value.

[0021] The sensor body in this embodiment is made of a low-temperature resistant sapphire chip. Sapphire is a material with excellent low-temperature resistance, which can maintain its physical and chemical stability at extremely low temperatures and is suitable for applications such as LNG tank trucks that need to work in low-temperature environments.

[0022] The pressure sensing element in this embodiment is a diffused silicon pressure sensor. Since the diffused silicon pressure sensor is a sensor that uses the piezoresistive effect of silicon material to measure pressure, and the resistance of silicon material changes with temperature, the use of diffused silicon pressure sensor through temperature compensation helps to improve the accuracy of measurement.

[0023] In addition, the volume of the diffused silicon pressure sensor can be made very small, which is suitable for applications with limited space. Moreover, the diffused silicon pressure sensor can be designed according to the needs to measure a wide range of pressures from low pressure to high pressure, and it also has good linear characteristics, so that there is a good linear relationship between the output signal and the pressure input. In addition, the diffused silicon pressure sensor can usually withstand certain vibrations and shocks, and is suitable for dynamic pressure measurement.

[0024] The temperature sensor 1 and the temperature sensor 2 described in this embodiment are both made of semiconductor thermistor material. Semiconductor thermistor is a material that is very sensitive to temperature changes and can accurately detect temperature changes. By combining the low-temperature resistant sapphire chip and semiconductor thermistor, the dual temperature compensation pressure sensor for LNG tank trucks can provide high-precision and high-stability pressure measurement under extreme temperature conditions while maintaining a small size and low cost. These characteristics are crucial to ensuring the safe operation and effective monitoring of LNG tank trucks. Embodiment 2

[0025] like Figure 2 As shown, in order to solve the above technical problems, the present invention discloses a temperature compensation method, which is implemented by using a dual temperature compensated pressure sensor in embodiment 1. The specific method is as follows: The measured pressure P, the temperature T1 of the LNG medium and the working environment temperature T2 are collected and converted into voltage signals U through the pressure sensing element, temperature sensor 1 and temperature sensor 2 respectively. Ｐ , U Ｔ1 and U Ｔ2 , and normalize the data; Establish a BP neural network model for temperature compensation; Through the BP neural network model, U Ｐ , U Ｔ1 and U Ｔ2 Perform data fusion to obtain the network output pressure P′ that approximates the measured pressure calibration value P; This embodiment includes 1 pressure sensor and 2 temperature sensors: one is the main sensor, i.e., the pressure sensing element, used to measure the measured pressure; the other two are auxiliary sensors, i.e., temperature sensor 1 and temperature sensor 2, mainly used to monitor the interference temperature from the medium and the surrounding environment. P' is the measured pressure, U Ｐ is the output of the pressure sensing element, T is the interference temperature, U Ｔ1 and U Ｔ2 Output signal of temperature sensor 1 and temperature sensor 2. Ｐ , U Ｔ1 and U Ｔ2 As the input of BP neural network, P is the output of BP network, that is, the pressure after eliminating the influence of temperature. ij is the network input and the connection weight between the two middle layers, T ki is the connection weight between the intermediate and output layers, θ ｉ ,θ ｋ are the node thresholds of the middle layer and output layer respectively.

[0026] like Figure 3 As shown in the figure, the specific working process of constructing the BP neural network is as follows: S1. Input training samples, test samples and ideal output samples; S2. Normalize the sample data to obtain a training set; S3. Set network parameters and build BP neural network; S4. Set the number of iterations, target error, and use the measured sample data to train and test the BP neural network; S5. Output model structure coefficients; S6. Input the test samples into the trained model and return the results to the integrated processing before output.

[0027] Based on the temperature-compensated pressure sensor for LNG tank trucks in the above embodiment, the effect of temperature compensation is verified by experiments. The specific test process is as follows: First, adjust the diffused silicon pressure sensor and temperature sensor to zero respectively, apply an increasing pressure to the measuring diaphragm of the diffused silicon pressure sensor, and then put the diffused silicon pressure sensor into a constant temperature box, increase the temperature successively, and record the output value U Ｔ , U Ｐ , record the output values ​​of temperature from 20℃-55℃ and pressure from 0-80kPa respectively, and draw curves, such as Figure 4 shown.

[0028] The BP neural network is used to compensate for the temperature. After temperature compensation, there is no obvious noise point. The predicted pressure at different temperatures is basically on a straight line, and the output pressure value is less affected by temperature. Figure 5 shown.

[0029] The above test results show that by detecting the changes in ambient temperature and medium temperature, the compensation module is used to adjust the pressure reading to eliminate or reduce the influence of temperature on pressure measurement, thereby improving the measurement accuracy and stability under different temperature conditions. It can effectively solve the problem of low medium temperature and large changes in ambient temperature during the use of LNG tank trucks, which have a great impact on the measurement accuracy of the diffused silicon principle pressure transmitter.

[0030] Obviously, the above embodiments are merely examples for clear explanation and are not intended to limit the implementation methods. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation methods here. The obvious changes or modifications derived from these are still within the protection scope of the invention.

Claims

1. A dual temperature compensated pressure sensor, characterized in that: include: The sensor body includes a pressure-sensitive element and a temperature sensor. The pressure-sensitive element is used to sense pressure P and output a voltage signal U. p The temperature sensor is used to sense the temperature T1 of the medium and output a voltage signal U T1 ; Temperature sensor 2, the temperature sensor 2 is used to sense the temperature T2 of the surrounding environment and output a voltage signal U T2 ; The compensation module uses a compensation algorithm to compensate the pressure value U detected by the pressure sensing element according to the temperature change detected by the temperature sensor 1 and the temperature sensor 2. p Adjust and compensate, and finally obtain the corrected pressure value P′.

2. A dual temperature compensated pressure sensor according to claim 1, characterized in that: The compensation module includes a signal conditioning module, a microprocessor, a D / A conversion module and a communication module. The voltage signals of the pressure-sensitive element, temperature sensor 1 and temperature sensor 2 are amplified, filtered and conditioned by the signal conditioning module and then transmitted to the microprocessor. The microprocessor outputs the processed results through the D / A conversion module to correct the pressure value.

3. A dual temperature compensated pressure sensor according to claim 2, characterized in that: The compensation algorithm in the compensation module adopts BP neural network to adjust the pressure compensation value according to the real-time temperature change.

4. A dual temperature compensated pressure sensor according to claim 3, characterized in that: The BP neural network includes an input layer, at least one hidden layer and an output layer. The input layer receives the voltage signals output by the pressure sensing element and the temperature sensing element, the hidden layer is used to process the data transmitted from the input layer, and the output layer is used to output the predicted pressure value.

5. A dual temperature compensated pressure sensor according to claim 1, characterized in that: The sensor body is made of a low-temperature-resistant sapphire chip.

6. A dual temperature compensated pressure sensor according to claim 1, characterized in that: The pressure sensing element is a diffused silicon pressure sensor.

7. A dual temperature compensated pressure sensor according to claim 1, characterized in that: The temperature sensor 1 and the temperature sensor 2 are both made of semiconductor thermistor material.

8. A temperature compensation method for a temperature-compensated pressure sensor for LNG tank trucks according to any one of claims 1 to 7, characterized in that: The specific method is as follows: The measured pressure P, the temperature T1 of the LNG medium and the working environment temperature T2 are collected and converted into voltage signals U through the pressure sensing element, temperature sensor 1 and temperature sensor 2 respectively. Ｐ , U Ｔ1 and U Ｔ2 , and normalize the data; Establish a BP neural network model for temperature compensation; Through the BP neural network model, U Ｐ , U Ｔ1 and U Ｔ2 Data fusion is performed to obtain the network output pressure P′ that approximates the measured pressure calibration value P.

9. A dual temperature compensated pressure sensor according to claim 8, characterized in that: The specific working process of constructing BP neural network is as follows: S1. Input training samples, test samples and ideal output samples; S2. Normalize the sample data to obtain a training set; S3. Set network parameters and build BP neural network; S4. Set the number of iterations, target error, and use the measured sample data to train and test the BP neural network; S5. Output model structure coefficients; S6. Input the test samples into the trained model and return the results to the integrated processing before output.

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