A range automatic switching control system and method of a flow calibration device

Abstract

A range automatic switching control system and method of a flow calibration device, the system comprising a multi-stage sensor array connected in parallel and partially overlapping in range, a high-speed switching valve group for controlling the on-off of each flow path, a signal acquisition unit, and a central control unit. The central control unit intelligently judges and executes the range switching instruction according to the acquired instantaneous flow, flow calibration range, fluid temperature, and pipeline pressure, etc. characteristic parameters, and realizes undisturbed range switching through pre-charge pressure and rapid synchronous switching. The present application realizes full-automatic undisturbed range switching in the flow calibration process. The system always selects the optimal range sensor, maintaining high resolution and high accuracy within the full flow range. Through pre-charge pressure and millisecond-level rapid switching, it ensures that the flow fluctuation is less than 0.1%, and the calibration process is continuous and uninterrupted. The intelligent decision mechanism can actively predict and avoid the risk of over-range, effectively protecting the sensor, and greatly improving the calibration efficiency, data reliability, and equipment safety.

Description

Technical Field

[0001] This invention relates to the field of fluid measurement and metering technology, and in particular to an automatic range switching control system and method for a flow calibration device. Background Technology

[0002] Flow calibration devices are standard equipment used to calibrate various flow meters. Their core performance indicators include measurement range, accuracy, and resolution. In practical industrial applications, it is often necessary to cover a wide flow range, from extremely low to extremely high (e.g., 0.1 m³ / h to 1000 m³ / h). Current calibration devices and methods mainly include fixed-range methods and manual switching of multiple devices. However, existing flow calibration device technologies have significant limitations in achieving wide-range, high-precision measurements.

[0003] For the fixed-range method: This method uses a single flow sensor. To cover the widest possible flow range, a sensor with a large range must be selected. However, this method has an inherent drawback: the sensor's resolution is usually a fixed percentage of its full-scale range. Therefore, when measuring small flow rates close to the lower limit of the range, the sensor's effective resolution drops sharply, resulting in measurement accuracy failing to meet the requirements of high-precision calibration. In other words, the fixed-range method cannot simultaneously achieve a wide measurement range and high resolution, creating a contradiction between measurement range and accuracy. For the manual switching of multiple devices method: To resolve the above contradiction, existing technologies have employed multiple calibration devices with different ranges connected in parallel, or manually switched to different range calibration pipelines via valves. While this method addresses the resolution issue to some extent by using optimal sensors in different flow segments, it introduces several new problems: cumbersome operation, low efficiency, heavy reliance on manual operation, low automation, and low calibration efficiency. The switching process involves interruptions and fluctuations. During manual valve switching, the fluid path inevitably changes, leading to flow interruptions and pressure fluctuations, making the calibration process discontinuous and affecting the reliability and authority of the calibration data. Introducing human error and equipment risks: Manual operation is prone to human judgment and operational errors, and improper operation (such as misoperation under high pressure or high flow) poses a risk of damaging precision sensors. Furthermore, the system cannot proactively prevent sensors from being used beyond their range in real time.

[0004] In summary, existing flow calibration devices suffer from several problems, including a contradiction between measurement range and resolution, the inability to achieve seamless switching leading to discontinuous calibration processes, and the risk of damage due to over-range operation caused by improper operation or untimely response. Summary of the Invention

[0005] To address the aforementioned problems, this invention proposes an automatic range switching control system and method for a flow calibration device. This method and system can automatically select the optimal measurement range based on real-time flow, achieving high-resolution, disturbance-free continuous measurement over a wide range, and effectively protecting the sensor from over-range impact.

[0006] To achieve the above objectives, the technical solution of the present invention is: an automatic range switching control system for a flow rate calibration device, comprising: Multi-level sensor array: composed of at least two flow sensors with different ranges and partially overlapping ranges connected in parallel; High-speed switching valve assembly: connected to the flow path of each sensor in the multi-stage sensor array, used to control the on / off state of each flow path; Signal acquisition unit: electrically connected to the output terminals of all flow sensors in the multi-level sensor array, acquiring the raw signals of each sensor in real time, and performing filtering, amplification and AD conversion; The central control unit is electrically connected to the signal acquisition unit and the high-speed switching valve group; it includes: The flow characteristic recognition module is used to extract the instantaneous flow value, flow calibration range, fluid temperature, and pipeline pressure characteristic parameters of the current working sensor in real time based on the flow signal of the current working sensor collected by the signal acquisition unit. The intelligent switching decision module is used to compare the feature parameters with a preset threshold to determine whether the range switching conditions are met and generate a range switching decision command. After generating the range switching decision command, the module controls the high-speed switching valve group to pre-charge the target sensor flow path. After the pre-charging is completed, the module controls the high-speed switching valve group to simultaneously perform the operation of closing the current sensor flow path and opening the target sensor flow path.

[0007] The data fusion and output module is used to fuse measurement data from different sensors before and after the intelligent switching decision module determines that a range switching needs to be performed, and output a continuous and smooth final flow value. The length of the fusion time window is adaptively adjusted according to the stabilization time of the pipeline medium flow, and is generally 3-5 minutes.

[0008] Furthermore, the intelligent switching decision module is configured to perform the following pre-charge control: The inlet valve of the target sensor flow path is opened to a preset micro-opening degree, which can be dynamically adjusted according to the target flow rate setting value and the real-time main pipeline pressure. Real-time monitoring of the pressure at the inlet of the target sensor flow path and comparison with the main pipeline pressure; When the pressure at the inlet of the target sensor flow path reaches the preset ratio range of the main pipeline pressure and the pressure change rate is lower than the set threshold, the pre-charging is determined to be complete.

[0009] Furthermore, the switching judgment logic of the intelligent switching decision module includes: When the instantaneous flow rate value in the characteristic parameter is higher than the first safety threshold of the current sensor range limit, a switching process to a larger range sensor is triggered. When the instantaneous flow rate value is lower than the second threshold of the current sensor range lower limit, and the signal-to-noise ratio of the current sensor signal is lower than the set value, a switching process to a smaller range sensor is triggered.

[0010] Furthermore, the inlet valve of the control target sensor flow path is opened to a preset micro-opening degree, specifically: the preset micro-opening degree is 5%-15%, and the inlet pressure of the target flow path reaches 90%-98% of the main pipeline pressure.

[0011] Furthermore, the high-speed shear valve assembly uses high-speed solenoid valves, and the response time of a single valve to be fully open or fully closed is less than 10 milliseconds.

[0012] Furthermore, the total time from issuing the switching command to the system completing the fluid path switching and stabilizing the output flow rate is less than 50 milliseconds.

[0013] Furthermore, the first safety threshold for the current sensor range upper limit is 95%Q. max (Maximum instantaneous flow rate value), the second threshold of the current sensor range lower limit is 5%Q min (Minimum instantaneous flow rate).

[0014] An automatic range switching control method for an automatic range switching control system based on a flow calibration device includes the following steps: Step 1: System initialization, by default one flow sensor is enabled as the current working sensor; Step 2: Monitor and collect the flow signal of the currently operating sensor in real time, and extract feature parameters including instantaneous flow value and flow change rate; Step 3: Compare the feature parameters with a preset threshold to determine whether the range switching conditions are met; Step 4: If the handover conditions are met, execute the seamless handover process, which includes: Step 41, Pre-charge step: Control the high-speed switching valve group to perform a pre-charge rapid switching step on the target sensor flow path, including: 1) Open the inlet valve of the target sensor flow path to the preset micro-opening degree, so that the fluid is slowly injected into the flow path; 2) Monitor the pressure change at the inlet of the target sensor flow path in real time and compare it with the pressure in the main pipeline; 3) When the inlet pressure of the target flow path reaches 90% to 98% of the main pipeline pressure and the pressure change rate is lower than the set threshold, it is determined that the pre-pressurization is complete; Step 42: After the pre-charging is completed, control the high-speed switching valve group to simultaneously close the valve of the current sensor flow path and fully open the valve of the target sensor flow path; Step 5: During and after the switching process, the measurement data from the current sensor and the target sensor are fused and processed, and a continuous final flow value is output.

[0015] The beneficial effects of this invention are as follows: Through the coordinated control of a multi-stage sensor array and a high-speed switching valve assembly, this invention achieves automatic, seamless switching across the entire measurement range. The system consistently selects the optimal range sensor for measurement, improving resolution in the low-flow range and achieving an overall accuracy of 0.5 grade, thus unifying range and accuracy. During the switching process, hydraulic balancing and data fusion technology ensure that flow fluctuations are less than 0.1%, resulting in continuous output without jumps. Combined with data fusion technology, the final output signal exhibits no step jumps. Simultaneously, the system possesses real-time flow characteristic monitoring and prediction capabilities, proactively predicting and avoiding over-range risks, providing active protection for the sensors, extending equipment lifespan, and providing stable and continuous measurement results, thereby improving the reliability of calibration data.

[0016] The present invention will now be described in detail with reference to the accompanying drawings and embodiments. Attached Figure Description

[0017] Figure 1 This is a block diagram of the control system of the present invention; Figure 2 This is a block diagram of the flow rate calibration device based on the standard table method water flow rate experiment of the present invention.

[0018] In the diagram: 1 High-speed switching valve one, 2 High-speed switching valve two, 3 High-speed switching valve three, 4 High-speed switching valve four, 5 High-speed switching valve five, 6 High-speed switching valve six, 7 High-speed switching valve seven, 8 High-speed switching valve eight, 9 High-speed switching valve nine, 10 High-speed switching valve ten, 11 High-speed switching valve eleven, 12 High-speed switching valve twelve, 13 Pressure regulator, 14 First water distributor, 15 Second water distributor, 16 Water collector, 17 Return water system, 18 Water tank, 19 Water pump, 21 DN400 pipeline standard flow meter, 22 DN250 pipeline standard flow meter (medium range), 23 DN100 pipeline standard flow meter, 24 First measured flow meter, 25 Second measured flow meter, 26 Third measured flow meter. Detailed Implementation

[0019] Example 1: An automatic range switching control system for a flow calibration device includes: Multi-level sensor array: composed of at least two flow sensors with different ranges and partially overlapping ranges connected in parallel; High-speed switching valve assembly: connected to the flow path of each sensor in the multi-stage sensor array, used to control the on / off state of each flow path; Signal acquisition unit: electrically connected to the output terminals of all flow sensors in the multi-level sensor array, acquiring the raw signals of each sensor in real time, and performing filtering, amplification and AD conversion; The central control unit is electrically connected to the signal acquisition unit and the high-speed switching valve group; it includes: The flow characteristic recognition module is used to extract characteristic parameters such as instantaneous flow value, flow calibration range, fluid temperature, and pipeline pressure of the current working sensor in real time based on the flow signal of the current working sensor collected by the signal acquisition unit. The intelligent switching decision module is used to compare the feature parameters with a preset threshold to determine whether the range switching conditions are met and generate a range switching decision command. After generating the range switching decision command, the module controls the high-speed switching valve group to pre-charge the target sensor flow path. After the pre-charging is completed, the module controls the high-speed switching valve group to simultaneously perform the operation of closing the current sensor flow path and opening the target sensor flow path.

[0020] The data fusion and output module is used to fuse measurement data from different sensors before and after the intelligent switching decision module determines that a range switching needs to be performed, and output a continuous and smooth final flow value. The length of the fusion time window is adaptively adjusted according to the stabilization time of the pipeline medium flow, and is generally 3-5 minutes.

[0021] It should be noted that the extracted feature parameters are key real-time information used for intelligent range switching decisions, and mainly include, but are not limited to: Instantaneous flow rate: The real-time flow rate reading of the currently operating sensor, in m³ / h, which is the direct basis for judging range switching.

[0022] Flow calibration range: The standard range of the current working sensor and its preset high and low operating boundaries are used to determine whether the current flow rate is within the optimal measurement range of the sensor.

[0023] Fluid temperature: The real-time temperature value of the medium obtained by the pipeline temperature sensor, in °C, is used for temperature compensation of the sensor and to determine the state of the medium.

[0024] Pipeline pressure: Real-time pressure value of the current flow path obtained by a pressure transmitter, in MPa, used to monitor system stability, determine pre-pressurization status and assess hydraulic shock risk.

[0025] Traffic change rate: The rate of change of instantaneous traffic relative to time. It is used to determine whether the traffic is in a stable state and to avoid switching during periods of drastic fluctuations.

[0026] Signal-to-noise ratio (SNR): The signal-to-noise ratio of the current sensor output signal is used to evaluate the reliability of measurement data under low flow conditions and is one of the important criteria for switching down.

[0027] Valve status feedback: The actual opening degree, response time and sealing status of each high-speed switching valve are used to ensure the synchronization and reliability of the switching action.

[0028] In this embodiment, the intelligent switching decision module is further configured to perform the following pre-charge control: The inlet valve of the target sensor flow path is opened to a preset micro-opening degree, which can be dynamically adjusted according to the target flow rate setting value and the real-time main pipeline pressure. Real-time monitoring of the pressure at the inlet of the target sensor flow path and comparison with the main pipeline pressure; When the pressure at the inlet of the target sensor flow path reaches the preset ratio range of the main pipeline pressure and the pressure change rate is lower than the set threshold, the pre-charging is determined to be complete.

[0029] In this embodiment, the switching judgment logic of the intelligent switching decision module includes: When the instantaneous flow rate value in the characteristic parameter is higher than the first safety threshold of the current sensor range limit, a switching process to a larger range sensor is triggered. When the instantaneous flow rate value is lower than the second threshold of the current sensor range lower limit, and the signal-to-noise ratio of the current sensor signal is lower than the set value, a switching process to a smaller range sensor is triggered.

[0030] In this embodiment, the inlet valve of the control target sensor flow path is opened to a preset micro-opening degree, specifically: the preset micro-opening degree is 5%-15%, and the inlet pressure of the target flow path reaches 90%-98% of the main flow pressure.

[0031] In this embodiment, the valves used in the high-speed shear valve group are high-speed solenoid valves, and the response time of a single valve to be fully open or fully closed is less than 10 milliseconds.

[0032] In this embodiment, the total time from issuing the switching command to the system completing the fluid path switching and stabilizing the output flow rate value is less than 50 milliseconds.

[0033] In this embodiment, the first safety threshold of the current sensor range upper limit is set to 95%Q. max (Maximum instantaneous flow rate value), the second threshold of the current sensor range lower limit is 5%Qmin (Minimum instantaneous flow rate).

[0034] Example 2: Based on Embodiment 1, this embodiment is an automatic range switching control method for an automatic range switching control system based on a flow calibration device, comprising the following steps: Step 1: System initialization, by default one flow sensor is enabled as the current working sensor; Step 2: Monitor and collect the flow signal of the currently operating sensor in real time, and extract feature parameters including instantaneous flow value and flow change rate; Step 3: Compare the feature parameters with a preset threshold to determine whether the range switching conditions are met; Step 4: If the handover conditions are met, execute the seamless handover process, which includes: Step 41, Pre-charge step: Control the high-speed switching valve group to perform a pre-charge rapid switching step on the target sensor flow path, including: 1) Open the inlet valve of the target sensor flow path to the preset micro-opening degree, so that the fluid is slowly injected into the flow path; 2) Monitor the pressure change at the inlet of the target sensor flow path in real time and compare it with the pressure in the main pipeline; 3) When the inlet pressure of the target flow path reaches 90% to 98% of the main pipeline pressure and the pressure change rate is lower than the set threshold, it is determined that the pre-pressurization is complete; Step 42: After the pre-charging is completed, control the high-speed switching valve group to simultaneously close the valve of the current sensor flow path and fully open the valve of the target sensor flow path; Step 5: During and after the switching process, the measurement data from the current sensor and the target sensor are fused and processed, and a continuous final flow value is output.

[0035] Example 3: A smart range switching system and method for a large-diameter water flow standard device like Figure 2 As shown, this embodiment provides an automatic range switching control system for a flow calibration device based on the standard meter method for water flow experiments, suitable for calibration of large-diameter, high-flow-range liquid flow meters. In the field of flow metering, the standard meter method is one of the mainstream methods for flow meter calibration and verification. This method requires the standard device to provide continuous, stable, and highly accurate standard flow values ​​across the entire flow range of the meter being tested. However, current calibration devices based on the standard meter method are limited by the aforementioned issues of range, switching, and continuity, making it difficult to meet the demands of modern calibration requiring high efficiency and high accuracy.

[0036] Water supply unit: water tank 18, water pump 19, pressure stabilizer 13; First water distributor 14: Distributes the stabilized water flow to three standard flow meter branches with different ranges; The system includes three standard flow meter branches (high, medium, and low flow rates), each equipped with a high-speed switching valve and a standard flow meter. The first distributor 14 connects to these three branches. The first branch uses a DN400 standard flow meter 21 for the high flow rate range (e.g., 800-1500 m³ / h), with a high-speed switching valve 3 on one side and a high-speed switching valve 4 on the other. The second branch uses a DN250 standard flow meter 22 for the medium flow rate range (e.g., 300-1000 m³ / h), with a high-speed switching valve 7 on one side and a high-speed switching valve 8 on the other. The third branch uses a DN100 standard flow meter 23 for the low flow rate range (e.g., 50-400 m³ / h), with a high-speed switching valve 11 on one side and a high-speed switching valve 12 on the other. These three branches connect to the second distributor 14. Second water distributor 15: redistributes the water flow that has passed through the standard flow meter to multiple branches of the flow meters under test; The flow meter under test branch: The second distributor splits into three branches, namely the fourth, fifth and sixth branches. The three branches are respectively equipped with the first flow meter 24, the second flow meter 25 and the third flow meter 26. The flow meters under test in the first branch are equipped with high-speed switching valve 1 and high-speed switching valve 2; the flow meters under test in the second branch are equipped with high-speed switching valve 5 and high-speed switching valve 6; the flow meters under test in the third branch are equipped with high-speed switching valve 9 and high-speed switching valve 10. Each branch is also equipped with a high-speed switching valve. Water collector 16 and return water system 17: collect water flow and return it to the water tank 18.

[0037] Phase 1: System Preparation and Initialization System power-on and self-test The central control unit starts up and performs communication and status self-checks on the water pumps, valves, and various sensors; by default, the medium-range standard flow meter branch (DN250 pipeline standard flow meter 22, high-speed switching valve 7 and high-speed switching valve 8) is opened, and the remaining valves are closed. The pipeline is filled with water and pressure is stabilized; the water pump is started to pump water from the water tank into the pressure-stabilized pipeline; after the pressure stabilizes, the system enters the calibration state.

[0038] Phase Two: Accessing the Test Form and Setting Parameters Select the branch of the meter to be tested; the operator selects the branch of the meter to be tested (e.g., DN400 meter) through the human-machine interface; the system automatically opens the corresponding branch valve (e.g., high-speed switching valve 1 and high-speed switching valve 2) and closes the valves of the other branches of the meter to be tested; set the calibration flow point by inputting or selecting the flow point to be calibrated (e.g., 1200 m³ / h, 700 m³ / h, 300 m³ / h, etc.); the system automatically selects the standard flow meter with the range that best matches the calibration flow point.

[0039] Phase 3: Intelligent Range Matching and Disruptive Switching Standard flow meter range determination: The central control unit performs the following determination based on the set flow point and the range of each standard flow meter: If the flow rate is ≥ 800 m³ / h → select a high-range standard flow meter (DN400, valves 3 and 4). If 300 m³ / h ≤ flow rate point < 800 m³ / h → select a medium-range standard flow meter (DN250, valves 7 and 8). If the flow rate is <300 m³ / h → select a low-range standard flow meter (DN100, valves 11 and 12). Perform a seamless handover: 1) Pre-start the target branch: Slightly open the inlet valve of the target standard flow meter branch (such as high-speed switching valve 7) to pre-pressurize the pipeline.

[0040] 2) Fast synchronous switching: Execute synchronously within 10ms: 3) Close the inlet and outlet valves of the current standard flow meter branch; 4) Fully open the inlet and outlet valves of the target standard flow meter branch.

[0041] Example: When switching from 1200 m³ / h to 700 m³ / h, first slightly open the high-speed switching valve 8 for pre-pressurization, then quickly close the high-speed switching valves 3 and 4, while simultaneously fully opening the high-speed switching valves 7 and 8.

[0042] Phase Four: Traffic Stabilization and Data Collection 1. Wait for the system to stabilize; after the switch is completed, the system enters the stability monitoring mode to monitor traffic fluctuations in real time; when the traffic change rate is lower than the set threshold (e.g., ±0.5% / s) and lasts for 5 seconds, it is determined to be stable.

[0043] 2. Synchronous data acquisition: The signal acquisition unit simultaneously reads the instantaneous flow rate value of the standard flow meter and the instantaneous flow rate value of the flow meter under test. The acquisition frequency is ≥100 Hz to ensure real-time data accuracy.

[0044] 3. Data Fusion and Output If a range switch occurs during the data acquisition process, the data fusion unit performs a weighted average of the data within a 20ms time window before and after the switch, outputting a smooth and continuous flow curve. The system calculates the indication error of the meter under test in real time and records the calibration data for that flow point.

[0045] Phase 5: Completion of Verification and System Reset The calibration process is stopped; after all flow points are calibrated, the system automatically closes all valves (except the return water valve); the water pump stops, and the system enters standby mode. The central control unit summarizes the data from each flow point and automatically generates a calibration report containing information such as error curves, repeatability, and uncertainty. The system resets to its initial state and awaits the connection of the next calibration instrument. Finally, it should be noted that the above is only used to illustrate the technical solutions of the present invention and not to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention (such as the application of various formulas, the order of steps, etc.) without departing from the spirit and scope of the technical solutions of the present invention.

Claims

1. An automatic range switching control system for a flow rate calibration device, characterized in that, include: Multi-level sensor array: composed of at least two flow sensors with different ranges and partially overlapping ranges connected in parallel; High-speed switching valve assembly: connected to the flow path of each sensor in the multi-stage sensor array, used to control the on / off state of each flow path; Signal acquisition unit: electrically connected to the output terminals of all flow sensors in the multi-level sensor array, acquiring the raw signals of each sensor in real time, and performing filtering, amplification and AD conversion; The central control unit is electrically connected to the signal acquisition unit and the high-speed switching valve group; it includes: The flow characteristic recognition module is used to extract the instantaneous flow value, flow calibration range, fluid temperature, and pipeline pressure characteristic parameters of the current working sensor in real time based on the flow signal of the current working sensor collected by the signal acquisition unit. The intelligent switching decision module is used to compare the feature parameters with a preset threshold to determine whether the range switching conditions are met and generate a range switching decision command. After generating the range switching decision command, the module controls the high-speed switching valve group to pre-charge the target sensor flow path. After the pre-charging is completed, the module controls the high-speed switching valve group to simultaneously perform the operation of closing the current sensor flow path and opening the target sensor flow path. The data fusion and output module is used to fuse measurement data from different sensors before and after the intelligent switching decision module determines that a range switching needs to be performed, and output a continuous and smooth final flow value. The length of the fusion time window is adaptively adjusted according to the stabilization time of the pipeline medium flow, and the fusion time is 3-5 minutes.

2. The automatic range switching control system according to claim 1, characterized in that, The intelligent switching decision module is configured to perform the following pre-charge control: The inlet valve of the target sensor flow path is opened to a preset micro-opening degree, which can be dynamically adjusted according to the target flow rate setting value and the real-time main pipeline pressure. Real-time monitoring of the pressure at the inlet of the target sensor flow path and comparison with the main pipeline pressure; When the pressure at the inlet of the target sensor flow path reaches the preset ratio range of the main pipeline pressure and the pressure change rate is lower than the set threshold, the pre-charging is determined to be complete.

3. The automatic range switching control system according to claim 1, characterized in that, The switching decision logic of the intelligent switching decision module includes: When the instantaneous flow rate value in the characteristic parameter is higher than the first safety threshold of the current sensor range limit, a switching process to a larger range sensor is triggered. When the instantaneous flow rate value is lower than the second threshold of the current sensor range lower limit, and the signal-to-noise ratio of the current sensor signal is lower than the set value, a switching process to a smaller range sensor is triggered.

4. The automatic range switching control system according to claim 2, characterized in that, Specifically, the inlet valve of the target sensor flow path is opened to a preset micro-opening degree: the preset micro-opening degree is 5%-15%, and the inlet pressure of the target flow path reaches 90%-98% of the main flow pressure.

5. The automatic range switching control system according to claim 1, characterized in that, The high-speed shear valve assembly uses high-speed solenoid valves, and the response time of a single valve to be fully open or fully closed is less than 10 milliseconds.

6. The automatic range switching control system according to claim 1, characterized in that, The total time from issuing the switching command to the system completing the fluid path switching and stabilizing the output flow rate is less than 50 milliseconds.

7. The automatic range switching control system according to claim 3, characterized in that, The first safety threshold for the current sensor range upper limit is 95%Q. max (Maximum instantaneous flow rate value), the second threshold of the current sensor range lower limit is 5%Q min (Minimum instantaneous flow rate).

8. An automatic range switching control method based on the system according to any one of claims 1 to 7, characterized in that, Includes the following steps: Step 1: System initialization, by default one flow sensor is enabled as the current working sensor; Step 2: Monitor and collect the flow signal of the currently operating sensor in real time, and extract feature parameters including instantaneous flow value and flow change rate; Step 3: Compare the feature parameters with a preset threshold to determine whether the range switching conditions are met; Step 4: If the handover conditions are met, execute the seamless handover process, which includes: Step 41, Pre-charge step: Control the high-speed switching valve group to perform a pre-charge rapid switching step on the target sensor flow path, including: 1) Open the inlet valve of the target sensor flow path to the preset micro-opening degree, so that the fluid is slowly injected into the flow path; 2) Monitor the pressure change at the inlet of the target sensor flow path in real time and compare it with the pressure in the main pipeline; 3) When the inlet pressure of the target flow path reaches 90% to 98% of the main pipeline pressure and the pressure change rate is lower than the set threshold, it is determined that the pre-pressurization is complete; Step 42: After the pre-charging is completed, control the high-speed switching valve group to simultaneously close the valve of the current sensor flow path and fully open the valve of the target sensor flow path; Step 5: During and after the switching process, the measurement data from the current sensor and the target sensor are fused and processed, and a continuous final flow value is output.

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