Flow detection system based on silicon diaphragm and piezoresistance

Abstract

The application relates to the technical field of flow detection, in particular to a flow detection system based on a silicon diaphragm and a piezoresistance. The flow detection 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 piezoresistance sensor according to the resistance change after compensation, judges the response speed performance of the piezoresistance sensor, calculates the average value of the resistance according to the resistance value of the silicon diaphragm when the response speed performance of the piezoresistance sensor is fast, calculates the residual square of the resistance according to the average value of the resistance, calculates the total square of the resistance according to the predicted value, calculates the linear coefficient of the resistance by using the residual square of the resistance and the total square of the resistance, and calculates by using the data after compensation, so that the error caused by temperature fluctuation can be effectively reduced, the measurement accuracy is further improved, and the linear degree of the resistance can be accurately quantified by calculating the linear coefficient of the resistance when the response speed performance of the piezoresistance sensor is fast, thereby improving the measurement precision.

Description

Technical Field

[0001] This invention relates to the field of flow detection technology, and more specifically, to a flow detection system based on silicon diaphragms and piezoresistive pressure. Background Technology

[0002] Existing flow detection technologies typically rely on traditional mechanical or electromagnetic sensors, which have limitations in terms of accuracy, response speed, and durability. Silicon diaphragm and piezoresistive sensors, due to their high sensitivity, miniaturization, and good mechanical properties, are gradually becoming emerging technologies in the field of flow detection. However, because of their high sensitivity, when a silicon diaphragm is placed in a specific location, temperature fluctuations in the diaphragm under different environments affect its resistance. This leads to changes in the diaphragm's resistance, increasing the error in flow measurement and slowing down the response speed of the piezoresistive sensor, thus reducing the accuracy and precision of flow measurement. Therefore, we provide a flow detection system based on silicon diaphragms and piezoresistive sensors. Summary of the Invention

[0003] The purpose of this invention is to provide a flow detection system based on silicon diaphragms and piezoresistive properties to solve the problems mentioned in the background art.

[0004] To achieve the above objectives, the present invention provides a flow detection system based on silicon diaphragm and piezoresistive pressure, including a fluctuation unit, a linear coefficient unit, a calculation and compensation unit, and a flow deformation unit;

[0005] The fluctuation change unit measures the temperature, pressure, and resistance of the silicon diaphragm using a temperature sensor, a pressure sensor, and a piezoresistive sensor. It calculates the average temperature based on the temperature data and then determines whether there is a temperature fluctuation in the silicon diaphragm. When there is a temperature fluctuation, the temperature fluctuation affects the resistance of the silicon diaphragm. It calculates the average initial resistance based on the measured resistance data and analyzes the resistance change. It then uses the temperature data and the analyzed resistance change to perform a compensation calculation for the resistance change.

[0006] The linear coefficient unit is used to receive the compensated resistance change in the fluctuation unit and the resistance value of the silicon diaphragm. It calculates the sensitivity of the piezoresistive sensor based on the compensated resistance change and judges the response speed of the piezoresistive sensor. When the response speed of the piezoresistive sensor is fast, it calculates the average resistance value and the square of the resistance residual based on the resistance value of the silicon diaphragm. It then uses a linearity algorithm to calculate the resistance linearity coefficient based on the square of the resistance residual and judges the level of the resistance linearity coefficient. When the calculated resistance linearity coefficient is close to 1, it indicates that the measurement error of the piezoresistive sensor is small.

[0007] The calculation compensation unit is used to receive the command that the measurement error of the piezoresistive sensor in the linear coefficient unit is small. By measuring the fluid, recording the fluid velocity, it calculates the drag force on the silicon diaphragm, and then calculates the average drag force based on the drag force on the silicon diaphragm. Based on the calculated average drag force and the drag force on the silicon diaphragm, it calculates the drag force standard deviation relative error. It uses the drag force standard deviation and the drag force relative error 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, it calculates the drag force error compensation coefficient based on the calculated average drag force and calculates the drag force compensation. It uses the compensated drag force to calculate the average drag force after compensation and uses the average drag force after compensation as the final drag force.

[0008] The flow deformation unit is used to receive the final drag force detection fluid flow rate in the calculation compensation unit, calculate the center deformation of the silicon diaphragm based on the final drag force, and then use the calculated center deformation of the silicon diaphragm to determine whether the silicon diaphragm has deformed. When the silicon diaphragm deforms, it is adjusted according to the detected fluid flow rate.

[0009] As a further improvement to this technical solution, the fluctuation change unit includes a fluctuation measurement module and a resistance change module;

[0010] The fluctuation measurement module distributes four symmetrical silicon diaphragms at corresponding measurement positions. Each silicon diaphragm integrates 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 integrated chip. At the same time as 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 to determine 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.

[0011] The resistance change module is used to receive commands from the measurement fluctuation module indicating a change in the resistance of the silicon diaphragm. The resistance change module obtains temperature and pressure data, the resistance value of the silicon diaphragm, and a set reference temperature from the measurement fluctuation module. It calculates the average initial resistance value based on the resistance value of the silicon diaphragm, analyzes the resistance change based on the pressure data and the average initial resistance value, and uses a linear compensation algorithm to calculate the compensation for the resistance change based on the analyzed resistance change, temperature data, and set reference temperature.

[0012] As a further improvement to this technical solution, the linear coefficient unit is used to receive the compensated resistance change in the resistance change module and the resistance value, pressure data, and number of recorded resistance measurements of the silicon diaphragm in the measurement fluctuation module. It calculates the piezoresistive sensor sensitivity based on the compensated resistance change and pressure data, and then uses the piezoresistive sensor sensitivity to determine the speed of the piezoresistive sensor's response. If the piezoresistive sensor has a fast response, the linearity algorithm is triggered, and the average resistance value is calculated based on the silicon diaphragm's resistance value. A linear regression model is used to predict the predicted resistance value of the silicon diaphragm. The squared resistance residual is calculated based on the average resistance value and the number of recorded resistance measurements. The total resistance square is then 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 squared resistance residual and the total resistance square. The calculated resistance linearity coefficient is then used to determine its strength. When the calculated resistance linearity coefficient is close to 1, it indicates a high resistance linearity coefficient, which means the piezoresistive sensor has a small measurement error.

[0013] The implementation principle of the linear coefficient of the resistor in the linear coefficient unit using the linearity algorithm is as follows:

[0014] The resistance linearity coefficient is calculated by collecting the squares of the resistance residuals and the total squares of the resistance. Specific algorithm formula: ;

[0015] in, It refers to the first The first piezoresistive sensor measured the... One resistance value, It refers to the first The first piezoresistive sensor measured the... Predicted value of each resistance value It refers to the first The average resistance value measured by each piezoresistive sensor.

[0016] The calculation compensation unit includes a drag force calculation module and a drag force error module;

[0017] The drag force calculation module receives a command from the piezoresistive sensor in the linear coefficient unit indicating a small measurement error. It then uses four symmetrical silicon diaphragms to measure the fluid flow, recording the projected area of ​​the diaphragms in the fluid flow direction and the fluid velocity. Based on these parameters, it calculates the drag force on the silicon diaphragms, thus obtaining the drag force on the silicon diaphragms. ,in, It refers to the first The drag force on the silicon diaphragm This refers to the drag coefficient. 1 refers to the fluid density, 2 refers to a constant, and the average drag force is calculated based on the drag force on the silicon diaphragm.

[0018] The drag force error module is used to receive the average drag force calculated in the drag force calculation module and the drag force on the silicon diaphragm, calculate the drag force standard deviation and relative error, and use the drag force standard deviation and drag force relative error to determine whether there is an error in the drag force on the silicon diaphragm. When the drag force standard deviation is greater than the set standard deviation parameter and the drag force relative error is greater than the set relative error parameter, it indicates that there is an error in the drag force on the silicon diaphragm.

[0019] As a further improvement to this technical solution, the calculation compensation unit also includes a drag force compensation module;

[0020] The drag force compensation module is used to receive the average drag force calculated in the drag force error module, calculate the drag force error compensation coefficient based on the calculated average drag force, calculate the drag force compensation based on the drag force compensation coefficient, calculate the average drag force after compensation using the compensated drag force, and use the average drag force after compensation as the final drag force.

[0021] The flow deformation unit is used to receive the final drag force from the drag force compensation module and calculate the projected area, drag force coefficient, and fluid density of the silicon diaphragm in the fluid flow direction in the drag force module. Using an integrated formula, it detects the fluid flow rate based on the final drag force, the projected area of ​​the silicon diaphragm in the fluid flow direction, the drag force coefficient, and the fluid density. It calculates the central deformation of the silicon diaphragm based on the final drag force and then uses the calculated central deformation of the silicon diaphragm to determine whether the silicon diaphragm has deformed. When the silicon diaphragm deforms, it adjusts the fluid flow rate according to the detected fluid flow rate to reduce the deformation of the silicon diaphragm within the set standard flow rate range.

[0022] The principle behind detecting fluid flow rate using the integrated formula in the flow deformation unit is as follows:

[0023] Collect the final drag force The projected area of ​​the silicon diaphragm in the direction of fluid flow. traction coefficient Fluid density Detect the fluid flow rate and obtain the detected fluid flow rate. Specific algorithm formula: .

[0024] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0025] 1. In this flow detection system based on silicon diaphragm and piezoresistive pressure, the linear coefficient unit calculates the sensitivity of the piezoresistive sensor based on the compensated resistance change and pressure data, and determines the response speed of the piezoresistive sensor. When the response speed of the piezoresistive sensor is fast, the average resistance is calculated based on the resistance value of the silicon diaphragm, and the predicted resistance value of the silicon diaphragm is predicted using a linear regression model. The square of the resistance residual is calculated based on the average resistance, and the total square of the resistance is calculated based on the predicted value. The resistance linear coefficient is calculated using the square of the resistance residual and the total square of the resistance. By calculating based on the compensated data, the error caused by temperature fluctuations can be effectively reduced, further improving the measurement accuracy. At the same time, calculating the resistance linear coefficient when the piezoresistive sensor has a fast response speed can accurately quantify the linearity of the resistance, thereby improving the measurement accuracy.

[0026] 2. In this flow detection system based on silicon diaphragm and piezoresistive pressure, the flow deformation unit detects the fluid flow rate based on the final drag force, the projected area of ​​the silicon diaphragm in the fluid flow direction, the drag force coefficient, and the fluid density. It then calculates the central deformation of the silicon diaphragm based on the final drag force and uses this calculated central deformation to determine if the silicon diaphragm has deformed. When deformation occurs, adjustments are made based on the detected fluid flow rate. Through the final drag force feedback, adaptive adjustment can be achieved, optimizing fluid flow rate detection. Real-time monitoring of the final drag force can prevent damage to the silicon diaphragm, reduce maintenance costs and downtime, and improve overall performance. Furthermore, by monitoring the final drag force deformation, the deformation state of the silicon diaphragm can be understood in real time, improving measurement accuracy and precision. Attached Figure Description

[0027] Figure 1 This is a block diagram of the unit of the present invention;

[0028] Figure 2 This is a block diagram of the module units of the present invention.

[0029] The meanings of the labels in the diagram are as follows:

[0030] 1. Fluctuation change unit; 11. Fluctuation measurement module; 12. Resistance change module; 2. Linear coefficient unit;

[0031] 3. Compensation calculation unit; 31. Traction calculation module; 32. Traction error module; 33. Traction compensation module;

[0032] 4. Flow deformation unit. Detailed Implementation

[0033] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0034] This invention provides a flow detection system based on silicon diaphragms and piezoresistive properties. Please refer to [link to relevant documentation]. Figures 1-2 It includes a fluctuation change unit 1, a linear coefficient unit 2, a calculation compensation unit 3, and a flow deformation unit 4;

[0035] The fluctuation change unit 1 measures the temperature, pressure, and resistance of the silicon diaphragm using temperature, pressure, and piezoresistive sensors. It calculates the average temperature based on the temperature data and then determines if temperature fluctuations exist on the silicon diaphragm. If temperature fluctuations exist, they affect the silicon diaphragm's resistance. The unit calculates the average initial resistance based on the measured resistance data and analyzes the resistance change. It then uses the temperature data and the analyzed resistance change to perform resistance compensation calculations. The linearity coefficient unit 2 receives the compensated resistance change and the silicon diaphragm's resistance from the fluctuation change unit 1. It calculates the piezoresistive sensor sensitivity based on the compensated resistance change and assesses its response speed. If the piezoresistive sensor has a fast response speed, it calculates the average resistance and the squared resistance residual based on the silicon diaphragm's resistance. Using a linearity algorithm, it calculates the resistance linearity coefficient based on the squared resistance residual and assesses its level. When the calculated resistance linearity coefficient is close to 1, it indicates... The piezoresistive sensor has a small measurement error. The calculation compensation unit 3 receives the command from the linear coefficient unit 2 that the piezoresistive sensor has a small measurement error. It measures the fluid, records the fluid velocity, calculates the drag force on the silicon diaphragm, and then calculates the average drag force based on the drag force on the silicon diaphragm. It calculates the drag force standard deviation relative error based on the calculated average drag force and the drag force on the silicon diaphragm. It uses the drag force standard deviation and the drag force relative error 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, it calculates the drag force error compensation coefficient based on the calculated average drag force and calculates the drag force compensation. It uses the compensated drag force to calculate the average drag force after compensation and uses the average drag force after compensation as the final drag force. The flow deformation unit 4 receives the final drag force detection fluid flow rate from the calculation compensation unit 3, calculates the silicon diaphragm center deformation based on the final drag force, and then uses the calculated silicon diaphragm center deformation to determine whether the silicon diaphragm has deformed. When the silicon diaphragm deforms, it adjusts according to the detected fluid flow rate.

[0036] The following is a more detailed explanation of the above units; please refer to [link / reference]. Figures 1-2 ;

[0037] The fluctuation change unit 1 includes a fluctuation measurement module 11 and a resistance change module 12;

[0038] The fluctuation measurement module 11 distributes four symmetrical silicon diaphragms at corresponding measurement positions. Each silicon diaphragm integrates a piezoresistive sensor. The temperature data of the silicon diaphragm is measured by the temperature sensor and pressure sensor in the composite sensor integrated chip. and stress data While measuring the temperature data of the silicon diaphragm, a piezoresistive sensor is used 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. (include , , , The average temperature is calculated based on the temperature data, and then compared with the set reference temperature. To determine if there are temperature fluctuations in the silicon film, if the calculated average temperature exceeds the set reference temperature... This indicates that there are temperature fluctuations in the silicon diaphragm. Since the silicon diaphragm has temperature fluctuations, and the piezoresistive sensor is located on the silicon diaphragm, the temperature fluctuations of the silicon diaphragm affect the resistance value of the silicon diaphragm, causing the resistance of the silicon diaphragm to change.

[0039] The resistance change module 12 is used to receive commands from the measurement fluctuation module 11 to indicate a change in the resistance of the silicon diaphragm. The resistance change module 12 obtains temperature data from the measurement fluctuation module 11. Pressure data The resistance value of silicon films and the set reference temperature From the resistance value of the silicon film The initial resistance values ​​of the four piezoresistive sensors were obtained. , , , Based on the initial resistance values ​​of the four piezoresistive sensors , , , Calculate the average initial resistance value Then based on the pressure data and average initial resistance value The analysis of resistance change is performed, and a linear compensation algorithm is used based on the analyzed resistance change. Temperature data and the set reference temperature Perform the compensation calculation for the resistance change, and pass the compensated resistance change command to the linear coefficient unit 2.

[0040] Analysis of the principle behind the change in resistance:

[0041] Collect stress data and average initial resistance value Analyze the change in resistance to obtain the analyzed change in resistance. Specific algorithm formula: ;

[0042] in, This refers to the piezoresistive coefficient. This formula is used to analyze the change in resistance. By analyzing the change in resistance, the measurement data can be compensated, errors can be reduced, and the accuracy of the measured change in resistance can be further improved.

[0043] The principle of using a linear compensation algorithm to compensate for resistance changes is as follows:

[0044] Collect and analyze the change in resistance Temperature data and the set reference temperature Compensate for the change in resistance, and obtain the change in resistance after compensation. Specific algorithm formula: ;

[0045] in, This refers to the temperature coefficient. This formula is used to compensate for changes in resistance. By analyzing the amount of resistance change and temperature data, the resistance change can be compensated more accurately, reducing temperature-induced errors and thus improving measurement accuracy.

[0046] Linear coefficient unit 2 is used to receive the compensated resistance change in resistance change module 12. and the resistance value of the silicon diaphragm in the fluctuation measurement module 11 Pressure data Record the number of resistance measurements. Based on the change in resistance after compensation Calculate the sensitivity of the piezoresistive sensor using pressure data. Then utilize the sensitivity of the piezoresistive sensor The response speed of a piezoresistive sensor is determined by setting sensitivity parameters. By calculating the sensitivity of the piezoresistive sensor, its response to pressure changes can be accurately quantified, thereby improving measurement accuracy. Furthermore, calculations based on compensated data can effectively reduce errors caused by temperature fluctuations, further improving the accuracy of measurement results. When the piezoresistive sensor sensitivity... If the sensitivity value exceeds the set parameter, it indicates that the piezoresistive sensor has a fast response speed, thus triggering the linearity algorithm based on the resistance value of the silicon diaphragm. Calculate the average resistance Predicting the resistivity of silicon films using a linear regression model Predicted value Based on the average resistance and the number of resistance measurements recorded Calculate the square of the resistance residual, and then based on the predicted value... and the number of resistance measurements recorded Calculate the total square of the resistance, and then use a linearity algorithm to calculate the resistance linearity coefficient based on the square of the resistance residuals and the total square of the resistance. Finally, use the calculated resistance linearity coefficient... To determine the level of resistance linearity, when the calculated resistance linearity coefficient... When the value is close to 1, it indicates that the calculated resistance linearity coefficient is... A high value indicates that the piezoresistive sensor has a small measurement error. By calculating the resistance linearity coefficient, the linearity of the resistance can be accurately quantified, thereby improving the measurement accuracy.

[0047] The implementation principle of the resistance linear coefficient using the linearity algorithm in linear coefficient unit 2:

[0048] The resistance linearity coefficient is calculated by collecting the squares of the resistance residuals and the total squares of the resistance. Specific algorithm formula: ;

[0049] in, It refers to the first The first piezoresistive sensor measured the... One resistance value, It refers to the first The first piezoresistive sensor measured the... Predicted value of each resistance value It refers to the first The average resistance value measured by each piezoresistive sensor is used to calculate the resistance linearity coefficient. By calculating the resistance linearity coefficient, the linearity of the resistance can be accurately quantified, thereby improving the measurement accuracy.

[0050] 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 that the measurement error of the piezoresistive sensor in the linear coefficient unit 2 is small, and then use four symmetrical silicon diaphragms to measure the fluid and record the projected area of ​​the silicon diaphragms in the direction of fluid flow. and fluid velocity Based on the projected area of ​​the silicon diaphragm in the direction of fluid flow and fluid velocity The drag force on the silicon diaphragm is calculated to obtain the drag force on the silicon diaphragm. ,in, It refers to the first The drag force on the silicon diaphragm This refers to the drag coefficient. "2" refers to fluid density, "2" refers to a constant, and "drag force" refers to the drag force exerted on the fluid by the piezoresistive force on the silicon diaphragm. By accurately measuring the drag force on the silicon diaphragm, the fluid flow velocity and pressure can be measured more precisely, thereby improving the accuracy of flow detection. The average drag force is then calculated based on the drag forces on the four silicon diaphragms. The number 4 refers to four silicon films.

[0051] The drag force error module 32 is used to receive the average drag force calculated in the drag force calculation module 31. and the drag force on the silicon film Based on the calculated average drag force and the drag force on the silicon film Calculate the standard deviation of drag force ,in, It refers to the first The first calculation on the silicon film The drag force is 4, which refers to 4 silicon diaphragms, and then the average drag force is calculated. and the drag force on the silicon film The relative error of the drag force is calculated to obtain the relative error of the drag force calculation. ,in, This refers to calculating the first The relative error of the drag force is calculated using the drag force standard deviation. The relative error of the drag force The system uses a set standard deviation parameter and a set relative error parameter to determine whether there is an error in the drag force on the silicon film. When the drag force standard deviation... The relative error of the drag force is greater than the set standard deviation parameter. When the relative error exceeds the set 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 accuracy of the measurement can be evaluated, the influence of random errors can be reduced, and abnormalities in the drag force can be detected in time, thereby improving the accuracy of the measurement.

[0052] The calculation compensation unit 3 also includes a drag force compensation module 33, which is used to receive the drag force error from the drag force error module 32. The first calculation on the silicon film One drag force and the calculated average drag force According to the The first calculation on the silicon film One drag force and the calculated average drag force Calculate the drag force error compensation coefficient Then according to the first The first calculation on the silicon film One drag force Calculate the drag force compensation using the drag force compensation coefficient. By introducing a drag force compensation coefficient, measurement deviations caused by measurement errors, environmental factors, and external interference can be reduced, thereby improving measurement accuracy. The average value of the compensated drag force is calculated using the compensated drag force, and this average value is taken as the final drag force. .

[0053] The flow deformation unit 4 is used to receive the final drag force in the drag compensation module 33. And the projected area of ​​the silicon diaphragm in the direction of fluid flow in the drag force calculation module 31 traction coefficient Fluid density Using the integrated formula based on the final drag force The projected area of ​​the silicon diaphragm in the direction of fluid flow. traction coefficient Fluid density By detecting fluid flow rate and providing feedback on the final drag force, adaptive adjustment can be achieved, optimizing fluid flow rate detection. Simultaneously, real-time monitoring of the final drag force can prevent damage to the silicon diaphragm, reduce maintenance costs and downtime, and improve overall performance. The central shape variable of the silicon film is calculated, and the calculated central shape variable of the silicon film is obtained. Where 3 and 16 refer to constant terms, This refers to the radius of the silicon film. This refers to the Young's modulus of the silicon film. This refers to the thickness of the silicon diaphragm. The calculated deformation at the center of the silicon diaphragm is then compared with the set deformation value to determine whether the silicon diaphragm has deformed. When the calculated deformation at the center of the silicon diaphragm is greater than the set deformation value, it indicates that the silicon diaphragm has deformed. By dynamically calculating and monitoring the deformation value, the deformation state of the silicon diaphragm can be understood in real time, improving the accuracy and precision of the measurement. The fluid flow rate can also be adjusted according to the detected fluid flow rate, adjusting the fluid flow rate to the set standard flow rate range to reduce the deformation of the silicon diaphragm.

[0054] The principle behind fluid flow detection using the integrated formula in flow deformation unit 4 is as follows:

[0055] Collect the final drag force The projected area of ​​the silicon diaphragm in the direction of fluid flow. traction coefficient Fluid density Detect the fluid flow rate and obtain the detected fluid flow rate. Specific algorithm formula: ;

[0056] This formula is used to detect fluid flow rate. Through the final drag force feedback, adaptive adjustment can be achieved to optimize the detection of fluid flow rate. At the same time, real-time monitoring of the final drag force can prevent damage to the silicon diaphragm, reduce maintenance costs and downtime, and improve overall performance.

[0057] The foregoing has shown and described 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 to the above embodiments. The embodiments and descriptions in the specification are merely preferred examples and are not intended to limit the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the present invention as claimed. The scope of protection of the present invention is defined by the appended claims and their equivalents.

Claims

1. A flow detection system based on silicon diaphragm and piezoresistive pressure, characterized in that: 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. It calculates the average temperature based on 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. It calculates the average initial resistance value based on the measured resistance data and analyzes the resistance change. It uses the temperature data and the analyzed resistance change to perform a compensation calculation for the resistance change. 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 sensitivity of the piezoresistive sensor based on the compensated resistance change, and judge the speed of the piezoresistive sensor response. When the piezoresistive sensor response is fast, calculate the average resistance 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 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 of the piezoresistive sensor in the linear coefficient unit (2) to measure the fluid, record the fluid velocity to calculate the drag force on the silicon diaphragm, and then calculate the average drag force based on the drag force on the silicon diaphragm. The drag force standard deviation relative error is calculated based on the calculated average drag force and the drag force on the silicon diaphragm. The drag force standard deviation and the drag force relative error are used 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, the drag force error compensation coefficient is calculated based on the calculated average drag force and the drag force compensation is calculated. The average drag force after compensation is used to calculate the average drag force after compensation and the average drag force after compensation is used as the final drag force. The flow deformation unit (4) is used to receive the final drag force detection fluid flow rate in the calculation compensation unit (3), calculate the center deformation of the silicon diaphragm based on the final drag force, and then use the calculated center deformation of the silicon diaphragm to determine whether the silicon diaphragm has deformed. When the silicon diaphragm deforms, it is adjusted according to the detected fluid flow rate.

2. The flow detection system based on silicon diaphragm and piezoresistive pressure according to claim 1, characterized in that: The fluctuation change unit (1) includes a fluctuation measurement module (11) and a resistance change module (12). The measurement fluctuation module (11) distributes four symmetrical silicon diaphragms in 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 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 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. The resistance change module (12) is used to receive the command from the measurement fluctuation module (11) that the resistance of the silicon diaphragm changes. The resistance change module (12) obtains temperature, pressure data, the resistance value of the silicon diaphragm, and the set reference temperature from the measurement fluctuation module (11). It calculates the average initial resistance value based on the resistance value of the silicon diaphragm, analyzes the resistance change based on the pressure data and the average initial resistance value, and uses a linear compensation algorithm to calculate the compensation for the resistance change based on the analyzed resistance change, temperature data, and set reference temperature.

3. The flow detection system based on silicon diaphragm and piezoresistive pressure 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, pressure data, and number of recorded resistance measurements of the silicon diaphragm in the measurement fluctuation module (11). It calculates the sensitivity of the piezoresistive sensor based on the compensated resistance change and pressure data, and then uses the sensitivity of the piezoresistive sensor to judge the speed of the piezoresistive sensor's response. When the piezoresistive sensor's response speed is fast, it triggers the linearity algorithm and calculates the average resistance based on the resistance value of the silicon diaphragm. It uses the linear regression model to predict the predicted value of the resistance value of the silicon diaphragm, calculates the square of the resistance residual based on the average resistance and the number of recorded resistance measurements, and then calculates the total square of the resistance based on the predicted value and the number of recorded resistance measurements. It uses the linearity algorithm to calculate the resistance linear coefficient based on the square of the resistance residual and the total square of the resistance, and then uses the calculated resistance linear coefficient to 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 indicates that the measurement error of the piezoresistive sensor is small.

4. The flow detection system based on silicon diaphragm and piezoresistive pressure according to claim 3, characterized in that: The implementation principle of the linear coefficient of the resistor in the linear coefficient unit (2) using the linearity algorithm is as follows: The resistance linearity coefficient is calculated by collecting the squares of the resistance residuals and the total squares of the resistance. Specific algorithm formula: ; in, It refers to the first The first piezoresistive sensor measured the... One resistance value, It refers to the first The first piezoresistive sensor measured the... Predicted value of each resistance value It refers to the first The average resistance value measured by each piezoresistive sensor.

5. The flow detection system based on silicon diaphragm and piezoresistive pressure according to claim 3, characterized in that: 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 that the measurement error of the piezoresistive sensor in the linear coefficient unit (2) 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, and calculate the projected area of ​​the silicon diaphragm in the fluid flow direction. and fluid velocity Calculate the drag force on the silicon diaphragm to obtain the drag force on the silicon diaphragm. ,in, It refers to the first The drag force on the silicon diaphragm This refers to the drag coefficient. 1 refers to the fluid density, 2 refers to a constant, and the average drag force is calculated based on the drag force on the silicon diaphragm. The drag force error module (32) is used to receive the average drag force calculated in the drag force calculation module (31) and the drag force on the silicon film, calculate the drag force standard deviation and relative error, and use the drag force standard deviation and the drag force relative error to determine whether there is an error in the drag force on the silicon film. When the drag force standard deviation is greater than the set standard deviation parameter and the drag force relative error is greater than the set relative error parameter, it indicates that there is an error in the drag force on the silicon film.

6. The flow detection system based on silicon diaphragm and piezoresistive pressure according to claim 5, characterized in that: The calculation compensation unit (3) also includes a drag compensation module (33); The drag force compensation module (33) is used to receive the average drag force calculated in the drag force error module (32), calculate the drag force error compensation coefficient based on the calculated average drag force, calculate the drag force compensation based on the drag force compensation coefficient, calculate the average drag force after compensation using the compensated drag force, and use the average drag force after compensation as the final drag force.

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

8. The flow detection system based on silicon diaphragm and piezoresistive pressure according to claim 7, characterized in that: The principle of detecting fluid flow rate using the integrated formula in the flow deformation unit (4) is as follows: Collect the final drag force The projected area of ​​the silicon diaphragm in the direction of fluid flow. traction coefficient Fluid density Detect the fluid flow rate and obtain the detected fluid flow rate. Specific algorithm formula: .

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