Method and device for improving response speed of turbine flowmeter

Abstract

The present invention provides a method and device for improving the dynamic response of a turbine flowmeter, which improves the dynamic response of the turbine flowmeter through a dynamic compensation algorithm and improves the flow measurement performance of the turbine flowmeter. The method includes the following steps: obtaining pressure signals at the outlet and inlet of the turbine flowmeter, a temperature signal of the turbine flowmeter, and a flowmeter signal; calculating a pressure differential signal based on the pressure signal at the outlet of the turbine flowmeter and the pressure signal at the inlet of the turbine flowmeter; inputting the pressure differential signal and the temperature signal at the current moment into a flow function model to obtain the output flow at the current moment; inputting the pressure differential signal and the temperature signal at the previous moment into the flow function model to obtain the output flow at the previous moment; obtaining the final flow rate after compensation at the previous moment; and calculating the compensated output flow at the current moment based on the final flow rate after compensation at the previous moment, the flowmeter signal at the current moment, the output flow at the current moment, and the output flow at the previous moment.

Description

Technical Field

[0001] The invention relates to a method and a device for improving the response speed of a turbine flowmeter, belonging to the technical field of hydraulic systems. Background Art

[0002] Since the working conditions of the hydraulic system of hydraulic excavators are very harsh, the measurement of hydraulic flow mainly adopts turbine flowmeter, but turbine flowmeter also has inherent problems such as large pressure loss and slow dynamic response.

[0003] At present, turbine flowmeters are widely used in the field of liquid flow measurement. Turbine flowmeters rely on the rotation speed of the internal turbine to characterize the size of the flow. Due to the influence of the inertia and friction of the turbine, the dynamic response of the turbine flowmeter is slow and it cannot be used in scenarios where the flow changes rapidly, which restricts the application scope of the turbine flowmeter.

[0004] Accurate measurement of transient flow in hydraulic oil circuits is crucial to the design of hydraulic systems. Existing turbine flowmeters have a slow response speed, with a response frequency usually no higher than 15Hz, which makes it difficult to meet the application requirements for transient flow measurement during crushing and stripping operations. Summary of the Invention

[0005] The purpose of the present invention is to overcome the deficiencies in the prior art and provide a method and device for improving the dynamic response of a turbine flowmeter. The method for improving the dynamic response of a turbine flowmeter through a dynamic compensation algorithm is mainly used to improve the flow measurement performance of a turbine flowmeter.

[0006] To achieve the above object, the present invention is implemented by adopting the following technical solutions:

[0007] In a first aspect, the present invention provides a method for improving the dynamic response of a turbine flowmeter, comprising the following steps:

[0008] Acquire a pressure signal of a turbine flowmeter outlet, a pressure signal of a turbine flowmeter inlet, a temperature signal of the turbine flowmeter, and a flowmeter signal of the turbine flowmeter;

[0009] Calculating a pressure differential signal based on a pressure signal at the turbine flowmeter outlet and a pressure signal at the turbine flowmeter inlet; wherein the pressure differential signal is the difference between the pressure signal at the turbine flowmeter inlet and the pressure signal at the turbine flowmeter outlet;

[0010] Input the current differential pressure signal and the current temperature signal into the flow function model to obtain the output flow at the current moment;

[0011] Input the pressure difference signal and the temperature signal at the previous moment into the flow function model to obtain the output flow at the previous moment;

[0012] Get the final flow after compensation at the previous moment;

[0013] The output flow rate after compensation at the previous moment is calculated based on the final flow rate after compensation at the previous moment, the flow meter signal at the current moment, the output flow rate at the current moment, and the output flow rate at the previous moment.

[0014] Furthermore, according to the flow meter signal Qt i , the current moment flow function model output flow Qs i And the flow function model output flow Qs at the previous moment i-1 Methods for calculating the final compensated flow rate include:

[0015] The flow change obtained by calculating the flow function model is as follows:

[0016] dQ i =Qs i -Qs i-1 (1)

[0017] The final compensated flow rate is calculated according to the following formula:

[0018] Q i =k*Qt i +(1-k)*(Q i-1 +dQ i ) (2)

[0019] Where:

[0020] Qt i ——The turbine flowmeter flow rate at the current moment (L / min)

[0021] Qs i ——Output flow rate at the current moment (L / min)

[0022] Qs i-1 ——Output flow rate at the previous moment (L / min)

[0023] dQ i ——Compensation flow at the current moment (L / min)

[0024] Q i ——Final flow rate after compensation at the current moment (L / min)

[0025] Q i-1 ——Final flow rate after compensation at the previous moment (L / min)

[0026] k——compensation coefficient (0≤k≤1).

[0027] Furthermore, the method further includes: adjusting the compensation coefficient to adjust the compensation amount, thereby adjusting the system response frequency.

[0028] Furthermore, the input of the flow function model is a pressure difference signal and a temperature signal, and the output is an output flow of the flow function model;

[0029] The method for obtaining the flow function model includes:

[0030] Acquire temperature, pressure difference and flow data sets; the temperature, pressure difference and flow data sets include flow data at various temperatures and pressure differences;

[0031] The temperature, pressure difference and flow data sets are used to obtain a flow function model through data fitting or regression algorithm. The flow function model is used to calculate the theoretical flow corresponding to a certain temperature and pressure difference.

[0032] Furthermore, methods for obtaining a flow function model through data fitting or regression algorithms include:

[0033] The flow function model is generated by performing data fitting or regression calculation using data software, wherein the mathematical software includes MATLAB.

[0034] Furthermore, the method of obtaining temperature, pressure difference and flow rate data sets includes:

[0035] Step A: Use a hydraulic test bench to adjust the flow rate from small to large through the flow meter, using a 20-level stepped flow loading to load the flow rate from the lowest range to the highest range;

[0036] Step B: synchronously collect pressure, temperature, and flow signals, and calculate the differential pressure signal between the inlet and outlet of the turbine flowmeter;

[0037] Step C: Adjust the liquid temperature and repeat steps A and B to obtain flow data at various temperatures and pressure differences, and then organize the temperature, pressure difference, and flow data sets.

[0038] In a second aspect, the present invention provides a device for improving the dynamic response of a turbine flowmeter, comprising:

[0039] Pressure sensors installed at the inlet and outlet of the turbine flowmeter respectively;

[0040] Temperature sensors installed at the inlet, outlet or flowmeter of the turbine flowmeter;

[0041] The data acquisition module is used to synchronously collect 2-way pressure signals, 1-way temperature signal, and 1-way flow meter signal, and transmit the data to the host computer via the USB bus;

[0042] The host computer is used to execute the method described in the first aspect and calculate the final flow rate after compensation in real time based on the collected data.

[0043] Furthermore, the host computer adjusts the compensation coefficient to adjust the compensation amount, thereby adjusting the system response frequency.

[0044] Compared with the prior art, the present invention has the following beneficial effects:

[0045] 1. The inlet and outlet pressure difference of a turbine flowmeter is directly proportional to the flow rate, and the pressure difference response speed is much higher than that of a turbine flowmeter. Therefore, the core is to use the pressure difference parameter to compensate for the turbine flow rate. The dynamic compensation method uses the change in pressure difference as the compensation amount. The greater the flow change, the stronger the compensation effect. When the flow rate is stable, the inlet and outlet pressure difference of the flowmeter is equal to 0, so there is no compensation effect on the turbine flowmeter, thus ensuring accuracy under low dynamic flow;

[0046] 2. The present invention can improve the response speed of the turbine flowmeter. The installation and operation of the entire device are simple and easy. At the same time, the compensation algorithm is concise and effective, and the compensation amount adjustment process is simple. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] Figure 1 This is the typical pressure difference-flow curve of the turbine flowmeter.

[0048] Figure 2 It is the data transmission process of the device. DETAILED DESCRIPTION

[0049] The present invention will be further described below in conjunction with the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solutions of the present invention and are not intended to limit the scope of protection of the present invention.

[0050] Example 1:

[0051] This embodiment provides a method for improving the dynamic response of a turbine flowmeter. The technical solution of the present invention is illustrated by taking the dynamic flow test of an excavator main pump as an example.

[0052] 1. Install the test device, mainly including:

[0053] ① Install flange blocks on the inlet and outlet of the turbine flowmeter, and connect them in series to the main pump oil circuit through the flange blocks. The main pump serves as the measured target and also as the hydraulic source for the calibration test.

[0054] ②Install a pressure measuring joint on each of the inlet and outlet flanges, and install a temperature sensor on the inlet flange.

[0055] ③Data acquisition module, typically DEWE43, synchronously collects 2-way pressure signals, 1-way temperature signal and 1-way flow meter signal. The host computer transmits data with the data acquisition module via the USB bus.

[0056] 2. Calibration method of flow function model

[0057] ① After connecting the electronically controlled hydraulic loading valve in series to the flow meter, the flow rate is adjusted from the lowest to the highest range by controlling the hydraulic loading valve. A typical 20-level stepped flow loading method is adopted.

[0058] ②Synchronously collect pressure, temperature, and flow signals during the entire loading process, and calculate the pressure difference signal at different temperatures and flows.

[0059] ③ Adjust the liquid temperature and repeat steps ① and ② to obtain flow data at various temperatures and pressure differences, and organize the temperature, pressure difference, and flow data sets.

[0060] ④ Through relevant algorithms such as data fitting, regression, neural network and other algorithms, establish the flow function model under different temperature and pressure difference input parameters.

[0061] 3. Dynamic compensation algorithm

[0062] ①Synchronously collect pressure, temperature and flow signals at equal intervals. The typical pressure difference-flow curve is as follows: Figure 1 shown.

[0063] ② The flow change obtained by the flow function model at the current moment:

[0064] dQ i =Qs i -Qs i-1 (1)

[0065] ④ Different algorithms can be used for flow compensation, such as Kalman filter algorithm, complementary filter algorithm, etc., but the purpose is to adjust the weight of turbine output and flow function model output under instantaneous state. The typical first-order complementary flow compensation algorithm is as follows:

[0066] The final compensated flow rate is calculated according to the following formula:

[0067] Q i =k*Qt i +(1-k)*(Q i-1 +dQ i ) (2)

[0068] Where:

[0069] Qt i ——The turbine flowmeter flow rate at the current moment (L / min)

[0070] Qs i ——Output flow rate at the current moment (L / min)

[0071] Qs i-1 ——Output flow rate at the previous moment (L / min)

[0072] dQi ——Compensation flow at the current moment (L / min)

[0073] Q i ——Final flow rate after compensation at the current moment (L / min)

[0074] Q i-1 ——Final flow rate after compensation at the previous moment (L / min)

[0075] k——compensation coefficient (0≤k≤1).

[0076] By adjusting the compensation coefficient in Formula 2, the dynamic response frequency of the system can be adjusted.

[0077] Specifically, the input of the flow function model is a pressure difference signal and a temperature signal, and the output is an output flow of the flow function model;

[0078] The method for obtaining the flow function model includes:

[0079] Acquire temperature, pressure difference and flow data sets; the temperature, pressure difference and flow data sets include flow data at various temperatures and pressure differences;

[0080] The temperature, pressure difference and flow data sets are used to obtain a flow function model through data fitting or regression algorithm. The flow function model is used to calculate the theoretical flow corresponding to a certain temperature and pressure difference.

[0081] Preferably, the method of obtaining the flow function model by data fitting or regression algorithm includes:

[0082] The flow function model is generated by performing data fitting or regression calculation using data software, wherein the mathematical software includes MATLAB.

[0083] In addition, the LSTM neural network can be trained through temperature, pressure difference and flow data sets to build a flow function model and output the model flow theory.

[0084] The inlet and outlet pressure differential of a turbine flowmeter is directly proportional to the flow rate, and the pressure differential response speed is much faster than that of a turbine flowmeter. Therefore, the key is to use the pressure differential parameter to compensate for the turbine flow rate. The dynamic compensation method uses the change in the pressure differential as the compensation amount. The greater the flow rate change, the stronger the compensation effect.

[0085] The present invention can improve the response speed of the turbine flowmeter, and the installation and operation of the entire device are simple and easy. At the same time, the compensation algorithm is concise and effective, and the compensation amount adjustment process is simple.

[0086] The present invention uses the turbine inlet and outlet pressure difference parameter as the compensation parameter, does not require an additional pressure difference generating structure, reduces oil circuit pressure loss, has a simple installation process, and has high measurement efficiency.

[0087] The present invention uses the flow function model to output the flow rate change as the compensation amount. The compensation effect only occurs when the flow is in a dynamic change process. There is no flow compensation effect in the steady state, so the accuracy in the steady state and low frequency can be guaranteed.

[0088] The present invention also adjusts the compensation amount by adjusting the compensation coefficient to achieve the effect of adjusting the system response frequency, which is simple and convenient.

[0089] Example 2:

[0090] This embodiment provides a device for improving the dynamic response of a turbine flowmeter, comprising:

[0091] Pressure sensors installed at the inlet and outlet of the turbine flowmeter respectively;

[0092] Temperature sensors installed at the inlet, outlet or flowmeter of the turbine flowmeter;

[0093] The data acquisition module is used to synchronously collect 2-way pressure signals, 1-way temperature signal, and 1-way flow meter signal, and transmit the data to the host computer via the USB bus;

[0094] The host computer is used to calculate the final flow rate after compensation in real time based on the collected data.

[0095] The host computer calculates the final flow rate after compensation in real time based on the collected data, including the following steps:

[0096] Real-time acquisition of turbine flowmeter inlet and outlet pressure signals, turbine flowmeter temperature signals, and turbine flowmeter flowmeter signal Qt i ;

[0097] Calculate the pressure difference signal between the inlet and outlet of the turbine flowmeter;

[0098] Input the current pressure difference signal and temperature signal into the flow function model to obtain the output flow Qs of the flow function model at the current moment i ;

[0099] Input the pressure difference signal and temperature signal of the previous moment into the flow function model to obtain the output flow Qs of the flow function model at the previous moment i-1 ;

[0100] The flow change obtained by calculating the flow function model is as follows:

[0101] dQ i =Qs i -Qs i-1 (1)

[0102] The final compensated flow rate is calculated according to the following formula:

[0103] Q i =k*Qt i +(1-k)*(Q i-1 +dQ i ) (2)

[0104] Where:

[0105] Qt i ——The turbine flowmeter flow rate at the current moment (L / min)

[0106] Qs i ——Output flow rate at the current moment (L / min)

[0107] Qs i-1 ——Output flow rate at the previous moment (L / min)

[0108] dQ i ——Compensation flow at the current moment (L / min)

[0109] Q i ——Final flow rate after compensation at the current moment (L / min)

[0110] Q i-1 ——Final flow rate after compensation at the previous moment (L / min)

[0111] k——compensation coefficient (0≤k≤1).

[0112] The host computer adjusts the compensation coefficient to adjust the compensation amount, thereby adjusting the system response frequency.

[0113] Specifically, the calibration method of the flow function model is:

[0114] ① After connecting the electronically controlled hydraulic loading valve in series to the flow meter, the flow rate is adjusted from the lowest to the highest range by controlling the hydraulic loading valve. A typical 20-level stepped flow loading method is adopted.

[0115] ②Synchronously collect pressure, temperature, and flow signals during the entire loading process, and calculate the pressure difference signal at different temperatures and flows.

[0116] ③ Adjust the liquid temperature and repeat steps ① and ② to obtain flow data at various temperatures and pressure differences, and organize the temperature, pressure difference, and flow data sets.

[0117] ④ Through relevant algorithms such as data fitting, regression, neural network and other algorithms, establish the flow function model under different temperature and pressure difference input parameters.

[0118] The host computer of this embodiment can execute the method described in the first embodiment.

[0119] The device of this embodiment can improve the response speed of the turbine flowmeter. The installation and operation of the entire device are simple and easy. At the same time, the compensation algorithm is concise and effective, and the compensation amount adjustment process is simple.

[0120] Those skilled in the art will appreciate that the embodiments of the present application can be provided as methods, systems, or computer program products. Therefore, the present application can adopt the form of a complete hardware embodiment, a complete software embodiment, or an embodiment in combination with software and hardware. Moreover, the present application can adopt the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to magnetic disk storage, CD-ROM, optical storage, etc.) that contain computer-usable program code.

[0121] The present application is described with reference to the flowcharts and / or block diagrams of the methods, devices (systems), and computer program products according to the embodiments of the present application. It should be understood that each process and / or box in the flowchart and / or block diagram, as well as the combination of the processes and / or boxes in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the steps in the process. Figure 1 a process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0122] These computer program instructions may also be stored in a computer readable memory that can direct a computer or other programmable data processing device to work in a specific manner, so that the instructions stored in the computer readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 a process or multiple processes and / or boxes Figure 1 The function specified in one or more boxes.

[0123] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operational steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing the instructions executed on the computer or other programmable device for implementing the process. Figure 1 a process or multiple processes and / or boxes Figure 1 A step that specifies a function in one or more boxes.

[0124] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the technical principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A method for improving the dynamic response of a turbine flowmeter, characterized in that: The following steps are involved: Acquire a pressure signal of a turbine flowmeter outlet, a pressure signal of a turbine flowmeter inlet, a temperature signal of the turbine flowmeter, and a flowmeter signal of the turbine flowmeter; Calculating a pressure differential signal based on a pressure signal at the turbine flowmeter outlet and a pressure signal at the turbine flowmeter inlet; wherein the pressure differential signal is the difference between the pressure signal at the turbine flowmeter inlet and the pressure signal at the turbine flowmeter outlet; Input the current differential pressure signal and the current temperature signal into the flow function model to obtain the output flow at the current moment; Input the pressure difference signal and the temperature signal at the previous moment into the flow function model to obtain the output flow at the previous moment; Get the final flow after compensation at the previous moment; Calculate the output flow rate after compensation at the current moment according to the final flow rate after compensation at the previous moment, the flow meter signal at the current moment, the output flow rate at the current moment, and the output flow rate at the previous moment; Calculate the compensated output flow rate based on the flow meter signal at the current moment, the output flow rate at the current moment, and the output flow rate at the previous moment, including: The flow change obtained by calculating the flow function model is as follows: （1） The final compensated flow rate is calculated according to the following formula: （2） Where: ——The turbine flowmeter flow rate at the current moment, L / min, ——Output flow at the current moment, L / min, ——The output flow rate at the previous moment, L / min, ——Compensation flow at the current moment, L / min, ——The final flow rate after compensation at the current moment, L / min, ——The final flow rate after compensation at the previous moment, L / min, ——Compensation coefficient, 0≤ k ≤1.

2. The method for improving the dynamic response of a turbine flowmeter according to claim 1, characterized in that: The method further includes: adjusting the compensation coefficient to adjust the compensation amount, thereby adjusting the system response frequency.

3. The method for improving the dynamic response of a turbine flowmeter according to claim 1, characterized in that: The method for obtaining the flow function model includes: Acquire temperature, pressure difference and flow data sets; the temperature, pressure difference and flow data sets include flow data at various temperatures and pressure differences; The temperature, pressure difference and flow data sets are used to obtain a flow function model through data fitting or regression algorithm. The flow function model is used to calculate the theoretical flow corresponding to a certain temperature and pressure difference.

4. A device for improving the dynamic response of a turbine flowmeter, characterized in that: include: Two pressure sensors are installed at the inlet and outlet of the turbine flowmeter respectively; Temperature sensor, installed on the inlet, outlet or flow meter of the turbine flowmeter; The data acquisition module is used to synchronously collect 2-way pressure signals, 1-way temperature signal, and 1-way flow meter signal, and transmit the data to the host computer via the USB bus; The host computer is used to calculate the final flow rate after compensation using the method of any one of claims 1 to 3.

5. The device for improving the dynamic response of a turbine flowmeter according to claim 4, characterized in that: The host computer adjusts the compensation coefficient to adjust the compensation amount, thereby adjusting the system response frequency.

Images