Flow detection system based on silicon diaphragm and piezoresistor

Abstract

The invention relates to the technical field of flow detection, in particular to a flow detection system based on a silicon diaphragm and a piezoresistor. The system comprises a fluctuation change unit, a linear coefficient unit, a calculation compensation unit and a flow deformation unit. The linear coefficient unit calculates the sensitivity of the piezoresistive sensor according to the compensated resistance change and judges the response speed performance of the piezoresistive sensor, when the response speed performance of the piezoresistive sensor is high, the resistance average value is calculated according to the resistance value of the silicon diaphragm, and the resistance residual error square is calculated according to the resistance average value; the total resistance square is calculated according to the predicted value, the resistance linear coefficient is calculated by using the resistance residual square and the total resistance square, and calculation is performed according to the compensated data, so that errors caused by temperature fluctuation can be effectively reduced, and the measurement accuracy is further improved; meanwhile, the resistance linear coefficient is calculated under the condition that the response speed performance of the piezoresistive sensor is high, the linearity of the resistance can be accurately quantified, and therefore the measurement precision is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of flow detection, and more specifically, to a flow detection system based on a silicon diaphragm and piezoresistance. Background Art

[0002] Existing flow detection technologies usually rely on traditional mechanical or electromagnetic sensors, which have certain limitations in terms of accuracy, response speed, and durability. Silicon diaphragms and piezoresistive sensors have gradually become emerging technologies in the field of flow detection due to their high sensitivity, miniaturization, and good mechanical properties. However, due to the excessively high sensitivity of silicon diaphragms and piezoresistive sensors, when the silicon diaphragm is arranged at a corresponding position, there will be temperature fluctuations in the silicon diaphragm under different environments. Since the piezoresistive sensor is on the silicon diaphragm, the temperature fluctuations of the silicon diaphragm affect the resistance value of the silicon diaphragm, causing a change in the silicon diaphragm resistance. Therefore, when measuring under temperature fluctuations, it increases the error in measuring the flow rate and slows down the response speed performance of the piezoresistive sensor, resulting in a decrease in the accuracy and precision of measuring the flow rate. Thus, we provide a flow detection system based on a silicon diaphragm and piezoresistive. Summary of the Invention

[0003] The purpose of the present invention is to provide a flow detection system based on a silicon diaphragm and piezoresistive to solve the problems raised in the above background art.

[0004] To achieve the above purpose, the present invention provides a flow detection system based on a silicon diaphragm and piezoresistive, including a fluctuation change unit, a linear coefficient unit, a calculation compensation unit, and a flow deformation unit; The fluctuation change unit measures the temperature, pressure data of the silicon diaphragm, and the resistance value of the silicon diaphragm through a temperature sensor, a pressure sensor, and a piezoresistive sensor, calculates the average temperature based on the temperature data, and then determines whether there are temperature fluctuations in the silicon diaphragm. When there are temperature fluctuations in the silicon diaphragm, the temperature fluctuations of the silicon diaphragm affect the resistance value of the silicon diaphragm. Calculate the average initial resistance value based on the measured resistance data and analyze the resistance change amount, and perform compensation calculation for the resistance change using the temperature data and the analyzed resistance change amount; The linear coefficient unit is used to receive the compensated resistance change in the fluctuation change unit and the resistance value of the silicon diaphragm, calculate the sensitivity of the piezoresistive sensor based on the compensated resistance change, and determine the speed of the response speed performance of the piezoresistive sensor. When the response speed performance of the piezoresistive sensor is fast, calculate the average resistance value based on the resistance value of the silicon diaphragm and calculate the square of the resistance residual. Use the linearity algorithm to calculate the resistance linear coefficient based on the square of the resistance residual, and determine the level of the resistance linear coefficient. When the calculated resistance linear coefficient is close to 1, it indicates that the measurement error of the piezoresistive sensor is small; The calculation compensation unit is used to receive the command with small measurement error of the piezoresistive sensor in the linear coefficient unit. By measuring the fluid, recording the fluid velocity to calculate the drag force on the silicon diaphragm, then calculating the average value of the drag force based on the drag force on the silicon diaphragm, calculating the relative error of the standard deviation of the drag force according to the calculated average value of the drag force and the drag force on the silicon diaphragm, using the standard deviation of the drag force and the relative error of the drag force to determine whether there is an error in the drag force on the silicon diaphragm. When there is an error in the drag force on the silicon diaphragm, calculating the drag force error compensation coefficient based on the calculated average value of the drag force and calculating the compensation of the drag force, calculating the average value of the compensated drag force using the compensated drag force, and taking the average value of the compensated drag force as the final drag force; The flow deformation unit is used to receive the final drag force in the calculation compensation unit to detect the fluid flow rate, calculate the deformation amount at the center of the silicon diaphragm according to the final drag force, and then use the calculated deformation amount at the center of the silicon diaphragm to determine whether the silicon diaphragm is deformed. When the silicon diaphragm is deformed, it is adjusted according to the detected fluid flow rate.

[0005] As a further improvement of this technical solution, the fluctuation change unit includes a measurement fluctuation module and a resistance change module; The measurement fluctuation module distributes four symmetric silicon diaphragms at corresponding measurement positions. Each silicon diaphragm is integrated with a piezoresistive sensor. The temperature and pressure data of the silicon diaphragm are measured by the temperature sensor and pressure sensor in the composite sensor integration chip. While measuring the temperature data of the silicon diaphragm, the resistance value of the silicon diaphragm is measured using the piezoresistive sensor, recording the number of resistance measurements, calculating the average temperature according to the temperature data and determining whether there is temperature fluctuation in the silicon diaphragm. When there is temperature fluctuation in the silicon diaphragm, the temperature fluctuation of the silicon diaphragm affects the resistance value of the silicon diaphragm.

[0006] The resistance change module is used to receive the command for the resistance change of the silicon diaphragm in the measurement fluctuation module. The resistance change module obtains the temperature, pressure data, the resistance value of the silicon diaphragm, and the set reference temperature from the measurement fluctuation module, calculates the average initial resistance value according to the resistance value of the silicon diaphragm, then analyzes the resistance change amount based on the pressure data and the average initial resistance value, and calculates the compensation of the resistance change using the linear compensation algorithm according to the analyzed resistance change amount, temperature data, and set reference temperature.

[0007] As a further improvement of the present technical solution, the linear coefficient unit is used to receive the compensated resistance change in the resistance change module, the resistance value, pressure data of the silicon diaphragm in the measurement fluctuation module, and the number of resistance measurements. The piezoresistive sensor sensitivity is calculated based on the compensated resistance change and pressure data, and then the response speed performance of the piezoresistive sensor is judged using the piezoresistive sensor sensitivity. When the response speed performance of the piezoresistive sensor is fast, the linearity algorithm is triggered, and the average resistance is calculated based on the resistance value of the silicon diaphragm. The predicted value of the resistance value of the silicon diaphragm is predicted using the linear regression model. The sum of squared residuals of resistance is calculated based on the average resistance and the number of recorded resistance measurements, and the total sum of squares of resistance is calculated based on the predicted value and the number of recorded resistance measurements. The resistance linear coefficient is calculated using the linearity algorithm based on the sum of squared residuals of resistance and the total sum of squares of resistance, and then the level of the resistance linear coefficient is judged using the calculated resistance linear coefficient. When the calculated resistance linear coefficient is close to 1, it indicates that the calculated resistance linear coefficient is high, which means that the measurement error of the piezoresistive sensor is small.

[0008] The implementation principle of the resistance linear coefficient using the linearity algorithm in the linear coefficient unit: Collect the sum of squared residuals of resistance and the total sum of squares of resistance to calculate the resistance linear coefficient, and obtain the calculated resistance linear coefficient , specific algorithm formula: Where, refers to the th resistance value measured by the th piezoresistive sensor, refers to the predicted value of the th resistance value measured by the th piezoresistive sensor, refers to the average value of the resistance values measured by the th piezoresistive sensor.

[0009] The calculation compensation unit includes a calculation drag force module and a drag force error module; The calculation drag force module is used to receive the command of small measurement error of the piezoresistive sensor in the linear coefficient unit, and then measure the fluid using four symmetric silicon diaphragms, record the projected area of the silicon diaphragm in the fluid flow direction and the fluid velocity, and calculate the drag force on the silicon diaphragm based on the projected area of the silicon diaphragm in the fluid flow direction and the fluid velocity, and obtain the drag force on the silicon diaphragm , where, refers to the drag force on the th silicon diaphragm, refers to the drag force coefficient, refers to the fluid density, 2 refers to a constant, and then calculate the average drag force based on the drag force on the silicon diaphragm; The drag force error module is used to receive the average drag force calculated by the drag force calculation module and the drag force on the silicon diaphragm, calculate the standard deviation and relative error of the drag force, and use the standard deviation and relative error of the drag force to determine whether there is an error in the drag force on the silicon diaphragm. When the standard deviation of the drag force is greater than the set standard deviation parameter and the relative error of the drag force is greater than the set relative error parameter, it indicates that there is an error in the drag force on the silicon diaphragm.

[0010] As a further improvement of this technical solution, the calculation compensation unit further includes a drag force compensation module; The drag force compensation module is used to receive the average drag force calculated by the drag force error module, calculate the drag force error compensation coefficient according to the calculated average drag force, then calculate the compensation of the drag force according to the drag force compensation coefficient, calculate the average value of the compensated drag force by using the compensated drag force, and use the average value of the compensated drag force as the final drag force.

[0011] The flow deformation unit is used to receive the final drag force in the drag force compensation module, the projected area of the silicon diaphragm in the fluid flow direction, the drag coefficient, and the fluid density in the drag force calculation module, detect the fluid flow rate by using the integration formula according to the final drag force, the projected area of the silicon diaphragm in the fluid flow direction, the drag coefficient, and the fluid density, calculate the central deformation of the silicon diaphragm according to the final drag force, then use the calculated central deformation of the silicon diaphragm to judge whether the silicon diaphragm is deformed. When the silicon diaphragm is deformed, it is adjusted according to the detected fluid flow rate, and the fluid flow rate is adjusted to the set standard flow rate range to reduce the deformation of the silicon diaphragm.

[0012] The principle of detecting the fluid flow rate by using the integration formula in the flow deformation unit is as follows: Collect the final drag force , the projected area of the silicon diaphragm in the fluid flow direction , the drag coefficient , the fluid density Detect the fluid flow rate to obtain the detected fluid flow rate , and the specific algorithm formula: .

[0013] Compared with the prior art, the beneficial effects of the present invention are: 1. In the flow detection system based on a silicon diaphragm and piezoresistance, the linear coefficient unit calculates the piezoresistive sensor sensitivity according to the compensated resistance change and pressure data, and judges the response speed performance of the piezoresistive sensor. When the response speed performance of the piezoresistive sensor is fast, the average resistance is calculated according to the resistance value of the silicon diaphragm, and the predicted value of the resistance value of the silicon diaphragm is predicted using a linear regression model. The sum of squared residuals of the resistance is calculated according to the average resistance, and the total sum of squares of the resistance is calculated according to the predicted value. The resistance linear coefficient is calculated using the sum of squared residuals of the resistance and the total sum of squares of the resistance. By calculating based on the compensated data, the error caused by temperature fluctuations can be effectively reduced, and the measurement accuracy can be further improved. At the same time, when calculating the resistance linear coefficient in the case of a fast response speed performance of the piezoresistive sensor, the linearity of the resistance can be accurately quantified, thereby improving the measurement accuracy.

[0014] 2. In the flow detection system based on a silicon diaphragm and piezoresistance, the flow deformation unit detects the fluid flow according to the final drag force, the projected area of the silicon diaphragm in the fluid flow direction, the drag coefficient, and the fluid density, and then calculates the deformation amount at the center of the silicon diaphragm according to the final drag force. The calculated deformation amount at the center of the silicon diaphragm is used to judge whether the silicon diaphragm deforms. When the silicon diaphragm deforms, it is adjusted according to the detected fluid flow. Through the feedback of the final drag force, adaptive adjustment can be realized, the detection of the fluid flow can be optimized, and the real-time monitoring of the final drag force can prevent the damage of the silicon diaphragm, reduce the maintenance cost and downtime, and improve the overall performance. At the same time, by monitoring the deformation amount through the final drag force, the deformation state of the silicon diaphragm can be understood in real time, and the measurement accuracy and accuracy can be improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 is the unit block diagram of the present invention; Figure 2 is the module unit block diagram of the present invention.

[0016] The meanings of the reference numerals in the figure are as follows: 1. Fluctuation change unit; 11. Measurement fluctuation module; 12. Resistance change module; 2. Linear coefficient unit; 3. Calculation compensation unit; 31. Calculation drag force module; 32. Drag force error module; 33. Drag force compensation module; 4. Flow deformation unit. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0017] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0018] The present invention provides a flow detection system based on a silicon diaphragm and piezoresistance. Please refer to Figure 1 - Figure 2 , which includes a fluctuation change unit 1, a linear coefficient unit 2, a calculation compensation unit 3, and a flow deformation unit 4; The fluctuation change unit 1 measures the temperature and pressure data of the silicon diaphragm and the resistance value of the silicon diaphragm through a temperature sensor, a pressure sensor, and a piezoresistive sensor, calculates the average temperature according to the temperature data, and then determines whether there is a temperature fluctuation in the silicon diaphragm. When there is a temperature fluctuation in the silicon diaphragm, the temperature fluctuation of the silicon diaphragm affects the resistance value of the silicon diaphragm. Calculate the average initial resistance value according to the measured resistance data and analyze the resistance change amount, and perform a compensation calculation for the resistance change using the temperature data and the analyzed resistance change amount; the linear coefficient unit 2 is used to receive the compensated resistance change and the resistance value of the silicon diaphragm in the fluctuation change unit 1, calculate the piezoresistive sensor sensitivity according to the compensated resistance change, and judge the response speed performance of the piezoresistive sensor. When the response speed performance of the piezoresistive sensor is fast, calculate the average resistance value according to the resistance value of the silicon diaphragm and calculate the square of the resistance residual. Use the linearity algorithm to calculate the resistance linear coefficient according to the square of the resistance residual, and judge the level of the resistance linear coefficient. When the calculated resistance linear coefficient is close to 1, it indicates that the measurement error of the piezoresistive sensor is small; the calculation compensation unit 3 is used to receive the command that the measurement error of the piezoresistive sensor in the linear coefficient unit 2 is small, measure the fluid, record the fluid velocity to calculate the drag force on the silicon diaphragm, and then calculate the average value of the drag force according to the drag force on the silicon diaphragm. Calculate the relative error of the drag force standard deviation according to the calculated average value of the drag force and the drag force on the silicon diaphragm, and use the drag force standard deviation and the relative error of the drag force to judge whether there is an error in the drag force on the silicon diaphragm. When there is an error in the drag force on the silicon diaphragm, calculate the drag force error compensation coefficient according to the calculated average value of the drag force and calculate the compensation of the drag force. Calculate the average value of the compensated drag force using the compensated drag force, and use the average value of the compensated drag force as the final drag force; the flow deformation unit 4 is used to receive the final drag force in the calculation compensation unit 3 to detect the fluid flow, calculate the central deformation amount of the silicon diaphragm according to the final drag force, and then use the calculated central deformation amount of the silicon diaphragm to judge whether the silicon diaphragm has deformed. When it is clear that the silicon diaphragm has deformed, adjust according to the detected fluid flow.

[0019] The following is a refinement of the above units. Please refer to Figure 1 - Figure 2 ; The fluctuation change unit 1 includes a measurement fluctuation module 11 and a resistance change module 12; The measurement fluctuation module 11 distributes four symmetric silicon diaphragms at corresponding measurement positions. Each silicon diaphragm is integrated with a piezoresistive sensor, and the temperature data of the silicon diaphragm is measured through the temperature sensor and the pressure sensor in the composite sensor integration chip and pressure data , while measuring the temperature data of the silicon diaphragm, use a piezoresistive sensor to measure the resistance value of the silicon diaphragm ( including (the resistance value measured by the piezoresistive sensor on the first silicon diaphragm), (the resistance value measured by the piezoresistive sensor on the second silicon diaphragm), (the resistance value measured by the piezoresistive sensor on the third silicon diaphragm), (the resistance value measured by the piezoresistive sensor on the fourth silicon diaphragm)), record the number of resistance measurements (including , , , ), calculate the average temperature based on the temperature data, and then use the calculated average temperature and the set reference temperature to determine whether there is temperature fluctuation in the silicon diaphragm. When the calculated average temperature exceeds the set reference temperature , it indicates that there is temperature fluctuation in the silicon diaphragm. Since there is temperature fluctuation in the silicon diaphragm and the piezoresistive sensor is on the silicon diaphragm, the temperature fluctuation of the silicon diaphragm affects the resistance value of the silicon diaphragm, causing a change in the silicon diaphragm resistance.

[0020] The resistance change module 12 is used to receive the command for the change in the silicon diaphragm resistance in the measurement fluctuation module 11. The resistance change module 12 obtains the temperature data , pressure data , the resistance value of the silicon diaphragm and the set reference temperature from the measurement fluctuation module 11. It obtains the initial resistance values of the 4 piezoresistive sensors from the resistance value of the silicon diaphragm , , , , calculates the average initial resistance value , , , based on the initial resistance values of the 4 piezoresistive sensors , then analyzes the resistance change amount according to the pressure data and the average initial resistance value . Using the linear compensation algorithm, it performs compensation calculation for the resistance change according to the analyzed resistance change amount , temperature data and the set reference temperature , and passes the compensated resistance change command into the linear coefficient unit 2.

[0021] Principle of analyzing the resistance change amount: Collect pressure data and the average initial resistance value Analyze the resistance change amount to obtain the analyzed resistance change amount , specific algorithm formula: ; Among them, refers to the piezoresistive coefficient. This formula is used for the analyzed resistance change amount. By analyzing the analyzed resistance change amount, the measurement data can be compensated, errors can be reduced, and the accuracy of measuring the resistance change amount can be further improved.

[0022] The principle of compensating the resistance change by using the linear compensation algorithm: Collect the analyzed resistance change amount , temperature data and the set reference temperature to compensate the resistance change and obtain the compensated resistance change , specific algorithm formula: ; Among them, refers to the temperature coefficient. This formula is used for compensating the resistance change. By analyzing the resistance change amount and temperature data, the resistance change can be compensated more precisely, the error caused by temperature can be reduced, and thus the measurement accuracy can be improved.

[0023] The linear coefficient unit 2 is used to receive the compensated resistance change in the resistance change module 12 and the resistance value of the silicon diaphragm in the measurement fluctuation module 11 , pressure data , the number of recorded resistance measurements , calculate the piezoresistive sensor sensitivity according to the compensated resistance change and the pressure data , and then use the piezoresistive sensor sensitivity to judge the response speed performance of the piezoresistive sensor with the set sensitivity parameter. By calculating the piezoresistive sensor sensitivity, the response ability of the sensor to pressure changes can be accurately quantified, thus improving the measurement accuracy. At the same time, by calculating according to the compensated data, the error caused by temperature fluctuation can be effectively reduced, and the accuracy of the measurement result can be further improved. When the piezoresistive sensor sensitivity is greater than the set sensitivity parameter, it indicates that the response speed performance of the piezoresistive sensor is fast, then trigger the linearity algorithm, and calculate the average resistance value according to the resistance value of the silicon diaphragm , use the linear regression model to predict the predicted value of the resistance value of the silicon diaphragm , calculate the sum of squared residuals of resistance according to the average resistance value and the number of recorded resistance measurements , and then according to the predicted value​​ and record the number of resistance measurements Calculate the total square of the resistance, and use the linearity algorithm to calculate the resistance linear coefficient based on the sum of the squares of the resistance residuals and the total square of the resistance. Then use the calculated resistance linear coefficient Judge the level of the resistance linear coefficient. When the calculated resistance linear coefficient is close to 1, it indicates that the calculated resistance linear coefficient is high, which means that the measurement error of the piezoresistive sensor is small. By calculating the resistance linear coefficient, the linearity of the resistance can be accurately quantified, thereby improving the measurement accuracy.

[0024] The implementation principle of the resistance linear coefficient using the linearity algorithm in the linear coefficient unit 2: Collect the sum of the squares of the resistance residuals and the total square of the resistance to calculate the resistance linear coefficient, and obtain the calculated resistance linear coefficient , and the specific algorithm formula: ; Among them, refers to the th resistance value measured by the th piezoresistive sensor, refers to the predicted value of the th resistance value measured by the th piezoresistive sensor, refers to the average value of the resistance values measured by the th piezoresistive sensor. This formula is used to calculate the resistance linear coefficient. By calculating the resistance linear coefficient, the linearity of the resistance can be accurately quantified, thereby improving the measurement accuracy.

[0025] The calculation compensation unit 3 includes a drag force calculation module 31 and a drag force error module 32. The drag force calculation module 31 is used to receive the command with small measurement error of the piezoresistive sensor in the linear coefficient unit 2, and then use four symmetric silicon diaphragms to measure the fluid, and record the projected area of the silicon diaphragm in the fluid flow direction and the fluid velocity , and calculate the drag force on the silicon diaphragm according to the projected area of the silicon diaphragm in the fluid flow direction and the fluid velocity , and obtain the drag force on the silicon diaphragm , among which, refers to the drag force on the th silicon diaphragm, refers to the drag force coefficient, refers to the fluid density, 2 refers to a constant, and the drag force refers to the drag force exerted by the piezoresistors on the silicon diaphragm on the fluid. By accurately measuring the drag force on the silicon diaphragm, the flow velocity and pressure of the fluid can be measured more accurately, thereby improving the accuracy of flow detection. Then, the average drag force is calculated based on the drag forces on 4 silicon diaphragms, and the calculated average drag force is obtained. , where 4 refers to 4 silicon diaphragms.

[0026] The drag force error module 32 is used to receive the average drag force calculated in the calculated drag force module 31 and the drag force on the silicon diaphragm , and based on the calculated average drag force and the drag force on the silicon diaphragm calculate the standard deviation of the drag force , where refers to the th drag force calculated on the th silicon diaphragm, 4 refers to 4 silicon diaphragms, and then based on the calculated average drag force and the drag force on the silicon diaphragm calculate the relative error of the drag force, and obtain the relative error of the calculated drag force , where refers to the relative error of calculating the th drag force. Using the standard deviation of the drag force and the relative error of the drag force to judge whether there is an error in the drag force on the silicon diaphragm compared with the set standard deviation parameter and the set relative error parameter. When the standard deviation of the drag force is greater than the set standard deviation parameter, and the relative error of the drag force is greater than the set relative error parameter, it indicates that there is an error in the drag force on the silicon diaphragm. By calculating the standard deviation of the drag force and the relative error of the drag force, the measurement accuracy can be evaluated, the influence of random errors can be reduced, and the abnormal situation of the drag force can be detected in time, improving the measurement accuracy.

[0027] The calculation compensation unit 3 further includes a drag force compensation module 33. The drag force compensation module 33 is used to receive the th drag force calculated on the th silicon diaphragm in the drag force error module 32 and the calculated average drag force , and based on the th drag force calculated on the th silicon diaphragm and the calculated average drag force calculate the drag force error compensation coefficient , and then based on the th drag force calculated on the th silicon diaphragm Compensate the drag force by calculating the drag force compensation coefficient , by introducing the drag force compensation coefficient, the measurement deviation caused by measurement errors, environmental factors and external disturbances can be reduced, the measurement accuracy can be improved, and the average value of the compensated drag force is calculated using the compensated drag force, and the average value of the compensated drag force is used as the final drag force .

[0028] The flow deformation unit 4 is used to receive the final drag force in the drag force compensation module 33 and calculate the projected area of the silicon diaphragm in the fluid flow direction in the drag force calculation module 31 , drag coefficient , fluid density , and detect the fluid flow rate using the integrated formula based on the final drag force , the projected area of the silicon diaphragm in the fluid flow direction , drag coefficient , fluid density , and through the feedback of the final drag force, adaptive adjustment can be achieved, the detection of the fluid flow rate can be optimized, and the real-time monitoring of the final drag force can prevent the damage of the silicon diaphragm, reduce the maintenance cost and downtime, and improve the overall performance. Calculate the central deformation of the silicon diaphragm according to the final drag force to obtain the calculated central deformation of the silicon diaphragm , where 3 and 16 refer to constant terms refers to the radius of the silicon diaphragm refers to the Young's modulus of the silicon diaphragm refers to the thickness of the silicon diaphragm, and then use the calculated central deformation of the silicon diaphragm and the set deformation to judge whether the silicon diaphragm is deformed. When the calculated central deformation of the silicon diaphragm is greater than the set deformation, it means that the silicon diaphragm is deformed. By dynamically calculating and monitoring the deformation, the deformation state of the silicon diaphragm can be understood in real time, the measurement accuracy and accuracy can be improved, and the fluid flow rate can be adjusted according to the detected fluid flow rate to adjust the fluid flow rate to within the set standard flow rate range to reduce the deformation of the silicon diaphragm.

[0029] The principle of detecting the fluid flow rate using the integrated formula in the flow deformation unit 4: Collect the final drag force , the projected area of the silicon diaphragm in the fluid flow direction , drag coefficient , fluid density to detect the fluid flow rate and obtain the detected fluid flow rate , and the specific algorithm formula: ; Among them, this formula is used to detect the fluid flow rate. Through the final drag force feedback, adaptive adjustment can be achieved to optimize the detection of the fluid flow rate. At the same time, the real-time monitoring of the final drag force can prevent the damage of the silicon diaphragm, reduce the maintenance cost and downtime, and improve the overall performance.

[0030] The above shows and describes the basic principles, main features and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited by the above embodiments. The above embodiments and descriptions in the specification are only preferred examples of the present invention and are not used to limit the present invention. Without departing from the spirit and scope of the present invention, the present invention will have various changes and improvements, and these changes and improvements all fall within the scope of the present invention claimed. The scope of protection claimed by the present invention is defined by the appended claims and their equivalents.

Claims

1. A flow detection system based on silicon diaphragm and piezoresistance, characterized by: It includes a fluctuation change unit (1), a linear coefficient unit (2), a calculation compensation unit (3) and a flow deformation unit (4); The fluctuation change unit (1) measures the temperature, pressure data and resistance value of the silicon diaphragm through a temperature sensor, a pressure sensor and a piezoresistive sensor, calculates an average temperature based on the temperature data, and then determines whether the silicon diaphragm has temperature fluctuations. When the silicon diaphragm has temperature fluctuations, the temperature fluctuations of the silicon diaphragm affect the resistance value of the silicon diaphragm. The average initial resistance value is calculated based on the measured resistance data and the resistance change is analyzed. The temperature data and the analyzed resistance change are used to perform compensation calculation for the resistance change. The linear coefficient unit (2) is used to receive the compensated resistance change in the fluctuation change unit (1) and the resistance value of the silicon diaphragm, calculate the sensitivity of the piezoresistive sensor according to the compensated resistance change, and judge the response speed performance of the piezoresistive sensor. When the response speed performance of the piezoresistive sensor is fast, calculate the average resistance value according to the resistance value of the silicon diaphragm and calculate the square of the resistance residual, calculate the resistance linear coefficient according to the square of the resistance residual using a linearity algorithm, and judge the resistance linear coefficient. When the calculated resistance linear coefficient is close to 1, it means that the measurement error of the piezoresistive sensor is small. The calculation compensation unit (3) is used to receive a command that the measurement error of the piezoresistive sensor in the linear coefficient unit (2) is small, and by measuring the fluid, the fluid velocity is recorded to calculate the drag on the silicon diaphragm, and then the drag average value is calculated based on the drag on the silicon diaphragm, and the relative error of the drag standard deviation is calculated based on the calculated drag average value and the drag on the silicon diaphragm, and the drag standard deviation and the relative error of the drag are used to determine whether there is an error in the drag on the silicon diaphragm. When there is an error in the drag on the silicon diaphragm, the drag error compensation coefficient is calculated based on the calculated drag average value and the drag compensation is calculated, and the average value of the compensated drag is calculated using the compensated drag, and the average value of the compensated drag is used as the final drag; The flow deformation unit (4) is used to receive the final drag detection fluid flow in the calculation compensation unit (3), calculate the central deformation amount of the silicon diaphragm according to the final drag, and then use the calculated central deformation amount of the silicon diaphragm to determine whether the silicon diaphragm is deformed. When the silicon diaphragm is deformed, it is adjusted according to the detected fluid flow.

2. The flow detection system based on silicon diaphragm and piezoresistance according to claim 1, characterized in that: The fluctuation variation unit (1) comprises a fluctuation measurement module (11) and a resistance variation module (12); The fluctuation measurement module (11) distributes four symmetrical silicon diaphragms at corresponding measurement positions, each silicon diaphragm is integrated with a piezoresistive sensor, and the temperature and pressure data of the silicon diaphragm are measured by a temperature sensor and a pressure sensor in a composite sensor integrated chip. While measuring the temperature data of the silicon diaphragm, the resistance value of the silicon diaphragm is measured by the piezoresistive sensor, the number of resistance measurements is recorded, the average temperature is calculated based on the temperature data, and it is determined whether the silicon diaphragm has temperature fluctuations. When the silicon diaphragm has temperature fluctuations, the temperature fluctuations of the silicon diaphragm affect the resistance value of the silicon diaphragm. The resistance change module (12) is used to receive a command for causing a change in the resistance of the silicon diaphragm in the measurement fluctuation module (11). The resistance change module (12) obtains temperature and pressure data, the resistance value of the silicon diaphragm, and a set reference temperature from the measurement fluctuation module (11), calculates an average initial resistance value based on the resistance value of the silicon diaphragm, analyzes the resistance change amount based on the pressure data and the average initial resistance value, and calculates compensation for the resistance change based on the analyzed resistance change amount, temperature data, and the set reference temperature using a linear compensation algorithm.

3. The flow detection system based on silicon diaphragm and piezoresistance according to claim 2, characterized in that: The linear coefficient unit (2) is used to receive the compensated resistance change in the resistance change module (12) and the resistance value of the silicon diaphragm in the measurement fluctuation module (11), pressure data, and the number of recorded resistance measurements, calculate the sensitivity of the piezoresistive sensor based on the compensated resistance change and pressure data, and then use the sensitivity of the piezoresistive sensor to judge the response speed performance of the piezoresistive sensor. When the response speed performance of the piezoresistive sensor is fast, the linearity algorithm is triggered, and the average resistance value is calculated based on the resistance value of the silicon diaphragm, and the predicted value of the resistance value of the silicon diaphragm is predicted using a linear regression model. The square of the resistance residual is calculated based on the resistance average value and the number of recorded resistance measurements, and then the total square of the resistance is calculated based on the predicted value and the number of recorded resistance measurements. The linearity algorithm is used to calculate the resistance linearity coefficient based on the square of the resistance residual and the total square of the resistance, and then the calculated resistance linearity coefficient is used to judge the high or low of the resistance linearity coefficient. When the calculated resistance linearity coefficient is close to 1, it means that the calculated resistance linearity coefficient is high, which means that the measurement error of the piezoresistive sensor is small.

4. The flow detection system based on silicon diaphragm and piezoresistance according to claim 3, characterized in that: The implementation principle of the resistance linear coefficient using the linearity algorithm in the linear coefficient unit (2) is: Collect the square of the resistance residual and the total square of the resistance to calculate the resistance linear coefficient, and obtain the calculated resistance linear coefficient , the specific algorithm formula is: ;in, Refers to the The piezoresistive sensor measures the The resistance value, Refers to the The piezoresistive sensor measures the The predicted value of the resistor value, Refers to the The average resistance value measured by the piezoresistive sensors.

5. The flow detection system based on silicon diaphragm and piezoresistance according to claim 3, characterized in that: The calculation compensation unit (3) comprises a drag calculation module (31) and a drag error module (32); The drag calculation module (31) is used to receive a command from the linear coefficient unit (2) that the measurement error of the piezoresistive sensor is small, and then use four symmetrical silicon diaphragms to measure the fluid, record the projected area of ​​the silicon diaphragm in the fluid flow direction and the fluid velocity, calculate the drag on the silicon diaphragm according to the projected area of ​​the silicon diaphragm in the fluid flow direction and the fluid velocity, and obtain the drag on the silicon diaphragm ,in, Refers to the The drag force on the silicon diaphragm is is the drag coefficient, refers to the fluid density, 2 refers to the constant, and the average drag force is calculated based on the drag force on the silicon diaphragm; The drag error module (32) is used to receive the drag average value calculated in the drag calculation module (31) and the drag on the silicon diaphragm, calculate the drag standard deviation and the relative error, and use the drag standard deviation and the drag relative error to determine whether there is an error in the drag on the silicon diaphragm. When the drag standard deviation is greater than a set standard deviation parameter and the drag relative error is greater than a set relative error parameter, it indicates that there is an error in the drag on the silicon diaphragm.

6. The flow detection system based on silicon diaphragm and piezoresistance according to claim 5, characterized in that: The calculation compensation unit (3) further comprises a drag compensation module (33); The drag compensation module (33) is used to receive the drag average value calculated in the drag error module (32), calculate the drag error compensation coefficient according to the calculated drag average value, then calculate the drag compensation according to the drag compensation coefficient, calculate the average value of the compensated drag using the compensated drag, and use the compensated drag average value as the final drag.

7. The flow detection system based on silicon diaphragm and piezoresistance according to claim 5, characterized in that: The flow deformation unit (4) is used to receive the final drag in the drag compensation module (33) and the projected area of ​​the silicon diaphragm in the fluid flow direction, the drag coefficient, and the fluid density in the drag calculation module (31), and use an integrated formula to detect the fluid flow according to the final drag, the projected area of ​​the silicon diaphragm in the fluid flow direction, the drag coefficient, and the fluid density, and calculate the central deformation of the silicon diaphragm according to the final drag, and then use the calculated central deformation of the silicon diaphragm to determine whether the silicon diaphragm is deformed. When the silicon diaphragm is deformed, it is adjusted according to the detected fluid flow, and the fluid flow is adjusted to within a set standard flow range to reduce the deformation of the silicon diaphragm.

8. The flow detection system based on silicon diaphragm and piezoresistance according to claim 7, characterized in that: The flow deformation unit (4) uses the integrated formula to detect the fluid flow to achieve the following principle: Collecting the final drag , the projected area of ​​the silicon diaphragm in the direction of fluid flow , drag coefficient , fluid density Detect the fluid flow rate and obtain the detected fluid flow rate , the specific algorithm formula is:

Images