CN117850484A - Flow control method, circuit and device - Google Patents
Flow control method, circuit and device Download PDFInfo
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- CN117850484A CN117850484A CN202311774621.0A CN202311774621A CN117850484A CN 117850484 A CN117850484 A CN 117850484A CN 202311774621 A CN202311774621 A CN 202311774621A CN 117850484 A CN117850484 A CN 117850484A
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- 239000007788 liquid Substances 0.000 claims abstract description 114
- 238000001514 detection method Methods 0.000 claims description 46
- 238000013016 damping Methods 0.000 abstract description 9
- 230000001276 controlling effect Effects 0.000 description 24
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- G—PHYSICS
- G05—CONTROLLING; REGULATING
- G05D—SYSTEMS FOR CONTROLLING OR REGULATING NON-ELECTRIC VARIABLES
- G05D7/00—Control of flow
- G05D7/06—Control of flow characterised by the use of electric means
- G05D7/0617—Control of flow characterised by the use of electric means specially adapted for fluid materials
- G05D7/0629—Control of flow characterised by the use of electric means specially adapted for fluid materials characterised by the type of regulator means
- G05D7/0635—Control of flow characterised by the use of electric means specially adapted for fluid materials characterised by the type of regulator means by action on throttling means
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Abstract
The application provides a flow control method, a flow control circuit and a flow control device, which can be applied to the technical field of data processing. Determining that the current flow rate of the liquid is greater than or equal to a first flow rate threshold value but less than a second flow rate threshold value, driving a first controller to control a valve for controlling the flow rate of the liquid, wherein the second flow rate threshold value is greater than the first flow rate threshold value; inputting a difference result of the current flow rate of the liquid and the second flow rate threshold value to a second controller to obtain a target control parameter for controlling the first controller; the first controller is adjusted to control the valve using the target control parameter. In this way, the control parameters of the first controller are adjusted by the second controller to emphasize the damping of the first controller. The stable control of smaller liquid flow is realized by using a double-controller mode, and the flow control precision is improved.
Description
Technical Field
The present disclosure relates to the field of data processing technologies, and in particular, to a flow control method, a circuit, and a device.
Background
The turbine flowmeter is composed of a turbine and an externally mounted sensor. When the liquid flows into the turbine, rotation of the impeller is caused. The sensor detects the rotational speed of its built-in impeller and uses this rotational speed to determine the flow rate of the liquid at that time. In practical applications, the turbine flowmeter can achieve the purpose of quantifying liquid by controlling the ball valve in the turbine.
When the impeller is rotated from stationary to rotary, the impeller needs to be rotated against the rotational inertia force required by the rotation of the impeller. Therefore, when the turbine flowmeter works at a small flow rate, the impact generated by the small liquid flow rate is insufficient to drive the impeller to rotate, so that the detected flow rate suddenly drops to 0, and the control feedback in the device suddenly becomes large, so that the control loop oscillates, and the flow rate cannot be controlled stably. That is, the control precision of the existing turbine flowmeter is low, and the smaller liquid flow cannot be controlled stably.
Disclosure of Invention
In view of the above, the present application provides a flow control method, circuit, and device, which can improve the flow control accuracy and stably control a small liquid flow.
In order to solve the problems, the technical scheme provided by the application is as follows:
in a first aspect, the present application provides a flow control method, the method comprising:
determining that the current flow rate of the liquid is greater than or equal to a first flow rate threshold value but less than a second flow rate threshold value, and driving a first controller to control a valve, wherein the valve is used for controlling the flow rate of the liquid, and the second flow rate threshold value is greater than the first flow rate threshold value;
inputting a difference result of the current flow rate of the liquid and the second flow rate threshold value to a second controller to obtain a target control parameter for controlling the first controller;
the first controller is adjusted to control the valve using the target control parameter.
In one possible implementation, the method further includes:
determining a minimum flow detection point by a trim valve controller, the minimum flow detection point having a first flow threshold;
and taking the first flow rate threshold value with a preset multiple as the second flow rate threshold value.
In one possible implementation, the method further comprises determining that the current flow rate of the liquid is less than a first flow rate threshold value: starting a micro flow time resolver and a PWM flow controller;
determining a closing duration of the valve using the micro flow time solver;
transmitting the closing time of the valve to the PWM flow controller, controlling the valve to be closed, and stopping the first controller;
and after the closing time of the valve is up, the current flow rate of the liquid is adjusted to the second flow rate threshold value, the first controller is started, and the PWM flow controller is closed.
In one possible implementation, the method further includes:
acquiring the rotating speed of an impeller;
a current flow rate of the liquid is determined based on the impeller speed.
In a second aspect, the present application provides a flow control circuit comprising:
the system comprises a flow rate detection module, a first controller, a second controller, a flow rate threshold module, a differentiator and a valve;
the input end of the first controller is respectively connected with the output end of the flow rate detection module, the output end of the second controller and the output end of the flow rate threshold module;
the input end of the second controller is connected with the output end of the differentiator;
the input end of the differentiator is respectively connected with the output end of the flow rate detection module and the output end of the flow rate threshold module;
the output end of the first controller is connected with the input end of the valve and is used for controlling the flow of liquid through the valve.
In one possible implementation, the flow control circuit further includes:
a flow recorder, a micro flow time solver and a PWM flow controller;
the input end of the flow recorder is connected with the output end of the flow velocity detection module, and the output end of the flow recorder is connected with the input end of the micro flow time resolver;
the input end of the PWM flow controller is respectively connected with the output end of the flow threshold module and the output end of the micro flow time resolver, and the output end of the PWM flow controller is connected with the input end of the valve.
In a third aspect, the present application provides a flow control device, the device comprising:
a driving unit, configured to determine that a current flow rate of the liquid is greater than or equal to a first flow rate threshold but less than a second flow rate threshold, and drive a first controller to control a valve, where the valve is used to control a flow rate of the liquid, and the second flow rate threshold is greater than the first flow rate threshold;
the acquisition unit is used for inputting the difference result of the current flow rate of the liquid and the second flow rate threshold value to a second controller to obtain a target control parameter for controlling the first controller;
and the control unit is used for adjusting the first controller by utilizing the target control parameter so as to control the valve.
In a possible implementation manner, the apparatus further includes a first determining unit and a second determining unit:
the first determining unit is used for determining a minimum flow detection point through the fine tuning valve controller, and the minimum flow detection point is provided with a first flow threshold;
the second determining unit is configured to take the first flow rate threshold value with a preset multiple as the second flow rate threshold value.
In one possible implementation, the apparatus further comprises: a starting unit and an adjusting unit;
the starting unit is used for starting the micro-flow time resolver and the PWM flow controller; determining a closing duration of the valve using the micro flow time solver;
the driving unit is further used for transmitting the closing time of the valve to the PWM flow controller, controlling the valve to be closed, and stopping the first controller;
and the adjusting unit is used for adjusting the current flow rate of the liquid to the second flow rate threshold value after the closing time of the valve is reached, starting the first controller and closing the PWM flow controller.
In a possible implementation manner, the apparatus further includes a third determining unit:
the acquisition unit is also used for acquiring the rotating speed of the impeller;
the third determining unit is configured to determine a current flow rate of the liquid based on the impeller rotation speed.
From this, this application has following beneficial effect:
the application provides a flow control method, which comprises the steps of firstly determining that the current flow rate of liquid is greater than or equal to a first flow rate threshold value but smaller than a second flow rate threshold value, and driving a first controller to control a valve for controlling the flow rate of the liquid, wherein the second flow rate threshold value is greater than the first flow rate threshold value; inputting a difference result of the current flow rate of the liquid and the second flow rate threshold value to a second controller to obtain a target control parameter for controlling the first controller; the first controller is adjusted to control the valve using the target control parameter. In this way, the control parameters of the first controller are adjusted by the second controller to emphasize the damping of the first controller. The stable control of smaller liquid flow is realized by using a double-controller mode, and the flow control precision is improved.
The embodiment of the application also provides a circuit for realizing the method and a device corresponding to the method, and the circuit has the same beneficial effects as the method.
Drawings
FIG. 1 is a schematic view of a turbine flowmeter according to an embodiment of the present disclosure;
fig. 2 is a schematic structural diagram of a flow control circuit according to an embodiment of the present disclosure;
fig. 3 is a schematic flow chart of a flow control method according to an embodiment of the present application;
FIG. 4 is a schematic waveform diagram of a flow control according to an embodiment of the present disclosure;
fig. 5 is a schematic structural diagram of a flow control device according to an embodiment of the present application.
Detailed Description
The following description of the embodiments of the present application will be made clearly and fully with reference to the accompanying drawings, in which it is evident that the embodiments described are only some, but not all, of the embodiments of the present application. All other embodiments, which can be made by one of ordinary skill in the art without undue burden from the present disclosure, are within the scope of the present disclosure.
In this application, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one … …" does not exclude the presence of other like elements in a process, method, article, or apparatus that comprises the element.
Turbine flow sensors are mainly classified into photoelectric detection and electromagnetic detection according to detection types. The photoelectric detection type has higher detection accuracy than the electromagnetic detection type, but has a certain requirement for transparency of the liquid, and the electromagnetic detection type has no requirement for the liquid. It should be noted that the turbine flow sensor of the present application may not be limited to the above types. For convenience of description, a specific description will be made below with respect to an electromagnetic detection type turbine flowmeter as an example.
Referring to fig. 1, fig. 1 is a schematic structural diagram of a turbine flowmeter according to an embodiment of the present application. The turbine flowmeter comprises a blade 1 with magnetic material, a turbine generator 2, a magnetic sensor (HALL sensor) 3, a ball valve 5 (valve) controlled by a motor 4, a water flow passage 6, and a magnet (not shown). When the liquid flows into a turbine flow meter as in fig. 1, rotation of the impeller is caused. The HALL sensor 3 detects the rotation speed of its built-in impeller and uses this rotation speed to determine the flow rate of the liquid at this time. In addition, the turbine flowmeter can achieve the purpose of quantifying liquid by controlling the ball valve 5.
The HALL sensor 3 requires a magnetic field to detect so that the impeller and the magnet will generate a certain attractive force. Meanwhile, when the impeller is rotated from stationary to rotary, the rotation inertial force required by the rotation of the impeller is overcome. Therefore, when the turbine flowmeter works under the condition of smaller flow, the impact generated by smaller liquid flow is insufficient to drive the impeller to rotate, so that the flow speed detection suddenly drops to 0, the control feedback suddenly becomes larger, and the control loop oscillates, so that the flow cannot be controlled stably. Namely, the control precision of the existing turbine flowmeter is low, and stable control cannot be performed on the condition of small liquid flow.
Based on the above, the present application provides a flow control method and apparatus, and provides a flow control circuit to implement the flow control method. Firstly, determining that the current flow rate of liquid is greater than or equal to a first flow rate threshold value but less than a second flow rate threshold value, and driving a first controller to control a valve for controlling the flow rate of the liquid, wherein the second flow rate threshold value is greater than the first flow rate threshold value; inputting a difference result of the current flow rate of the liquid and the second flow rate threshold value to a second controller to obtain a target control parameter for controlling the first controller; the first controller is adjusted to control the valve using the target control parameter. In this way, the control parameters of the first controller are adjusted by the second controller to emphasize the damping of the first controller. The stable control of smaller liquid flow is realized by using a double-controller mode, and the flow control precision is improved.
In order to facilitate understanding of the technical solution provided by the embodiments of the present application, a flow control method, a circuit and a device provided by the embodiments of the present application are described below with reference to the accompanying drawings.
Referring to fig. 2, fig. 2 is a schematic structural diagram of a flow control circuit according to an embodiment of the present application. The flow control circuit includes a flow rate detection module, a first controller, a second controller, a flow rate threshold module, a differentiator, and a valve. Wherein the first controller and the second controller are proportional-Integral-Differential (PID) controllers.
The input end of the first controller is respectively connected with the output end of the flow rate detection module, the output end of the second controller and the output end of the flow rate threshold module, and the output end of the first controller is connected with the input end of the valve and is used for controlling the flow of liquid through the valve. The input end of the second controller is connected with the output end of the differentiator, and the input end of the differentiator is respectively connected with the output end of the flow speed detection module and the output end of the flow speed threshold module.
The flow rate detection module is used for detecting the current flow rate of the liquid, the differentiator is used for determining a difference result between the current flow rate of the liquid and the second flow rate threshold value, and the flow rate threshold value module is used for determining the first flow rate threshold value and the second flow rate threshold value. The second controller is used for adjusting PID control parameters of the first controller, and the first controller accurately controls valve action based on the output of the flow rate detection module, the output of the second controller and the output of the flow rate threshold module, so that stable control of smaller liquid flow can be realized.
To further reduce the minimum controllable limit of the flowmeter, pulse width modulation (Pulse Width Modulation, PWM) control techniques can be incorporated into the flow control circuit to achieve less control of flow. In one possible implementation, the flow control circuit further includes: a flow recorder, a micro flow time solver and a PWM flow controller.
The input end of the flow recorder is connected with the output end of the flow velocity detection module, and the output end of the flow recorder is connected with the input end of the micro flow time resolver. The input end of the PWM flow controller is respectively connected with the output end of the flow speed threshold module and the output end of the micro flow time resolver, and the output end of the PWM flow controller is connected with the input end of the valve.
The flow recorder is used for determining an accumulated flow value of the liquid based on the current flow rate of the liquid output by the flow rate detection module, wherein the accumulated flow value of the liquid is the sum of flow values of the liquid flowing into the valve in a period from the start of the operation of the turbine flowmeter to the real-time moment in one period. The micro flow time solver is used to determine the closing duration of the valve.
The total liquid amount required to be input in one period is a preset value, and flow calculation is performed in a detectable interval, namely the time taken by the liquid flow rate from the second flow rate threshold value to the first flow rate threshold value is one period, wherein the first flow rate threshold value is the minimum flow rate which can be detected by the flow rate detection module. When the current flow rate of the detected liquid is smaller than the first flow rate threshold value, namely the detected flow rate suddenly drops to 0, the accumulated flow value of the input liquid meets a preset value required in a period.
And calculating the closing time required by the valve according to the micro flow time solver, namely calculating the holding time of the valve in the closing state. Optionally, the closing time of the valve is calculated by a micro flow time solver based on data from the flow logger. If the flow rate of the input liquid has reached the preset value at a certain time point in the cycle, the remaining time in the cycle may close the valve to wait for the next cycle to execute the liquid input again. I.e. the difference between the period duration and the time taken for inputting the liquid of the preset value is the closing duration of the valve. And transmitting the closing time of the valve to the PWM flow controller to control the valve to be closed, and stopping the first controller correspondingly.
After the closing time period is reached, the valve is opened, and the current flow rate of the liquid is adjusted to be a second flow rate threshold value. When the current flow rate of the liquid reaches the second flow rate threshold value, the next period is entered, the PWM flow controller stops working, and the first controller starts working. The control method with the accuracy higher than the minimum flow detected by the magnetic sensor is realized by comprehensively calculating the flow from the second flow threshold to the first flow threshold and the valve closing time.
The over-damping double PID control loop is combined with the PWM technology to realize the control of smaller flow, wherein a first controller of the over-damping double PID control is a flow control PID, the input is the current flow rate of liquid, the output is the valve opening degree, and the valve opening degree refers to the degree of opening or closing of the valve, namely the volume occupied by the valve in corresponding time through the change of the valve seat volume or the channel volume. The second controller is a control PID of the PID parameters of the first controller, inputs a difference value from the current flow rate to the second flow rate threshold value, and outputs a target control parameter of the first controller so as to emphasize the control damping of the first controller and prevent the flow rate from suddenly dropping to 0.
The flow control method provided by the embodiment of the application can be applied to the flow control circuit provided by the embodiment. Referring to fig. 3, fig. 3 is a flow chart of a flow control method according to an embodiment of the present application, where the method specifically includes S301 to S303.
S301: determining that the current flow rate of the liquid is greater than or equal to a first flow rate threshold value but less than a second flow rate threshold value, and driving a first controller to control a valve, wherein the valve is used for controlling the flow rate of the liquid, and the second flow rate threshold value is greater than the first flow rate threshold value.
And detecting the current flow rate of the liquid, and driving the first controller to control the valve when the current flow rate of the liquid reaches the second flow rate threshold value in a decreasing trend but is not lower than the first flow rate threshold value.
In one possible implementation, the current flow rate of the liquid may be obtained based on the impeller speed. The method further comprises the steps of: acquiring the rotating speed of an impeller; a current flow rate of the liquid is determined based on the impeller speed. The impeller speed can be obtained by means of the HALL sensor 3, the impeller speed being related to the flow rate of the liquid, the current flow rate of the liquid can be calculated on the basis of the impeller speed.
The second flow rate threshold may also be referred to as an unsteady state threshold for distinguishing between steady and unsteady regions of flow. The current flow rate of the liquid is greater than or equal to the first flow rate threshold value, but less than the second flow rate threshold value, namely the flow rate of the liquid is smaller in the unstable zone, and more accurate control can be realized by introducing the second controller.
In one possible implementation, the method further includes: determining a minimum flow detection point by a trim valve controller, the minimum flow detection point having a first flow threshold; and taking the first flow rate threshold value with a preset multiple as the second flow rate threshold value.
It should be noted that, the controllable minimum control accuracy of the turbine flowmeter is determined by the physical parameters of the whole device, and mainly depends on the minimum control accuracy of the valve, and the control accuracy of each device may be different.
The valve controller is used for controlling the opening degree of the valve, and the valve controller can be finely tuned to determine a minimum flow detection point, wherein the minimum flow detection point has a minimum flow rate, and the minimum flow rate is taken as a first flow rate threshold value. The first flow rate threshold value of the preset multiple is used as the second flow rate threshold value, the preset multiple can be set automatically based on actual conditions, and the preset multiple can be any value between 1.5 times and 2 times in the embodiment of the application. In this embodiment, the unstable interval is between the first flow rate threshold and the second flow rate threshold. The preset multiple of the first flow rate threshold is used as the second flow rate threshold, so that the valve can be controlled before the minimum flow rate is not reached, and the flow rate is prevented from suddenly dropping to 0.
In another possible implementation, the maximum change value that changes the flow rate without causing the flow rate detection module to measure 0 is taken as the second flow rate threshold under adjustment of the normal flow control parameter. The second flow rate threshold may be fine-tuned to a suitable point during production.
And when the current flow rate reaches the second flow rate threshold value in a reduced trend but does not reach the first flow rate threshold value, starting the second controller to control the PID control parameters of the first controller. The PID control parameters of the first controller (default light overdamping before adjustment) are adjusted based on the second controller to control the opening size of the valve.
S302: and inputting a difference result of the current flow rate of the liquid and the second flow rate threshold value to a second controller to obtain a target control parameter for controlling the first controller.
And adjusting the PID control parameters of the first controller through the second controller. Specifically, based on the differential result of the current flow rate of the liquid calculated by the differentiator and the second flow rate threshold, the second controller determines a target control parameter for controlling the first controller based on the differential result, so that the overall control effect damping of the first controller is emphasized.
S303: the first controller is adjusted to control the valve using the target control parameter.
The PID control parameter of the first controller is adjusted to the target control parameter, so that the first controller controls the valve to act at low flow, minimum fluctuation can be achieved, and the current flow rate of the liquid is controlled to approach the second flow rate threshold value, so that stable operation of the turbine flowmeter is ensured.
Based on the content of steps S301 to S303, when the current flow rate of the liquid is greater than or equal to the first flow rate threshold but less than the second flow rate threshold, the first controller controls the valve, and inputs the difference result between the current flow rate of the liquid and the second flow rate threshold to the second controller, so as to obtain the target control parameter for controlling the first controller; the first controller is regulated by the target control parameter to control the valve, so that the purpose of controlling the flow of the liquid is achieved. The control parameters of the first controller are controlled by the second controller to emphasize the damping of the first controller. The stable control of smaller liquid flow is realized by using a double-controller mode, and the flow control precision is improved.
In another embodiment of the present application, when the current flow rate of the liquid is less than the measurable minimum flow rate, the dual PID controller cannot meet the flow control purpose, i.e. the current flow rate of the liquid is less than the first flow rate threshold, the first controller controls the valve to adjust in the closing direction, the flow rate detected by the flow rate detection module is 0, and the micro-flow time resolver and the PWM flow controller will be started.
In one possible implementation, the method further comprises determining that the current flow rate of the liquid is less than a first flow rate threshold value: starting a micro flow time resolver and a PWM flow controller; determining a closing duration of the valve using the micro flow time solver; transmitting the closing time of the valve to the PWM flow controller, controlling the valve to be closed, and stopping the first controller; and after the closing time of the valve is up, the current flow rate of the liquid is adjusted to the second flow rate threshold value, the first controller is started, and the PWM flow controller is closed.
The total amount of liquid to be input in one period is a preset value, the time for the liquid flow rate to drop from the second flow rate threshold to the first flow rate threshold is one period, the period is a detectable unstable zone, and flow calculation is performed in the detectable unstable zone.
When the current flow rate of the detected liquid is smaller than the first flow rate threshold value, namely, the detected flow rate suddenly drops to 0, the accumulated flow value of the liquid input in the period at the moment meets the required preset value. And determining the closing time of the valve by using the micro flow time solver, namely calculating the closing time from closing the valve to the next period.
The closing time of the valve is calculated by a micro flow time solver based on the data of the flow recorder. If the flow value of the input liquid reaches the preset value at a certain time point in the period, the valve can be closed for the rest time in the period, and the next period is waited for executing liquid input again. I.e. the difference between the period duration and the time taken for inputting the liquid of the preset value is the closing duration of the valve. And transmitting the closing time of the valve to the PWM flow controller, controlling the valve to be closed, and stopping the first controller.
And after the closing time of the valve is up, the valve is opened, and the current flow rate of the liquid is adjusted to be a second flow rate threshold value. When the current flow rate of the liquid reaches the second flow rate threshold value, the next period is entered, the PWM flow controller stops working, and the first controller starts working.
After the valve is opened, the liquid flow rate is controlled to be adjusted to a second flow rate threshold value. After the current flow rate of the liquid reaches the second flow rate threshold, the next cycle is entered. Resetting the recorded data of the flow recorder, recording the accumulated flow value of the next period by the flow recorder, and normally detecting the current flow rate of the liquid by the flow rate detection module.
Because of calculation errors when the valve is closed and opened, the flow value at the stage is calibrated, so that more accurate flow control is realized. And the control of smaller flow is realized by comprehensively calculating the flow in the unstable region and the closing time of the valve.
It should be noted that the liquid is supplied to the turbine flowmeter continuously, and after the valve is opened, the flow rate of the liquid increases from the first flow rate threshold value to the second flow rate threshold value within the detectable unstable region.
Referring to fig. 4, fig. 4 is a schematic waveform diagram of a flow control provided in an embodiment of the present application, where S1 is a stage in which the first controller works, and S2 is a stage in which the PWM flow controller works. When the current flow rate of the liquid is smaller than the second flow rate threshold value but larger than the first flow rate threshold value, the first controller is in an operating state, and the PWM flow controller is in a closing state. When the current flow rate of the liquid is smaller than the first flow rate threshold value, the first controller is in a closed state, and the PWM flow controller is in an operating state. Thus, flow control with higher accuracy can be realized.
It should be noted that, the embodiment of the application uses the electromagnetic detection type turbine flowmeter as an example for explanation, and because the electromagnetic detection type turbine flowmeter has a working condition of smaller flow when in work, the working precision is higher, and the application range of the type flowmeter can be enlarged by applying the scheme of the embodiment of the application. The photoelectric detection type flowmeter does not have the participation of magnetic field suction, but also needs to overcome the thrust required by self rotation, so that the scheme described in the embodiment of the application can be used to achieve the flow detection result with higher precision. The embodiment of the application is a turbine flowmeter, improves the control precision, but does not limit a use object, and the scheme of the embodiment of the application is also suitable for other control equipment with a starting step so as to realize high-precision control.
The foregoing embodiments of the present application provide a flow control method based on the foregoing. Next, a flow control device, which is applied to a flow control circuit and performs the method shown in fig. 3, is further provided in the embodiment of the present application. The function of the flow rate control device will be described, and a schematic configuration of the flow rate control device is shown in fig. 5, and a driving unit 501, an acquiring unit 502, and a control unit 503 are shown.
A driving unit 501, configured to determine that a current flow rate of the liquid is greater than or equal to a first flow rate threshold but less than a second flow rate threshold, and drive a first controller to control a valve, where the valve is used to control a flow rate of the liquid, and the second flow rate threshold is greater than the first flow rate threshold;
an obtaining unit 502, configured to input a difference result between the current flow rate of the liquid and the second flow rate threshold to a second controller, so as to obtain a target control parameter for controlling the first controller;
a control unit 503 for adjusting the first controller to control the valve using the target control parameter.
In a possible implementation manner, the apparatus further includes a first determining unit and a second determining unit:
the first determining unit is used for determining a minimum flow detection point through the fine tuning valve controller, and the minimum flow detection point is provided with a first flow threshold;
the second determining unit is configured to take the first flow rate threshold value with a preset multiple as the second flow rate threshold value.
In one possible implementation, the apparatus further comprises: a starting unit and an adjusting unit;
the starting unit is used for starting the micro-flow time resolver and the PWM flow controller; determining a closing duration of the valve using the micro flow time solver;
the driving unit 501 is further configured to transmit a closing duration of the valve to the PWM flow controller, control the valve to close, and stop the first controller;
and the adjusting unit is used for adjusting the current flow rate of the liquid to the second flow rate threshold value after the closing time of the valve is reached, starting the first controller and closing the PWM flow controller.
In a possible implementation manner, the apparatus further includes a third determining unit:
the obtaining unit 502 is further configured to obtain an impeller rotation speed;
the third determining unit is configured to determine a current flow rate of the liquid based on the impeller rotation speed.
The embodiment of the application provides a flow control device, which comprises a driving unit, an acquisition unit and a control unit. The driving unit is used for determining that the current flow rate of the liquid is greater than or equal to a first flow rate threshold value but less than a second flow rate threshold value, and driving a first controller to control a valve, wherein the valve is used for controlling the flow rate of the liquid, and the second flow rate threshold value is greater than the first flow rate threshold value; the acquisition unit is used for inputting the difference result of the current flow rate of the liquid and the second flow rate threshold value to the second controller to obtain a target control parameter for controlling the first controller; the control unit is used for adjusting the first controller by utilizing the target control parameter so as to control the valve. The control parameters of the first controller are adjusted by the second controller to emphasize the damping of the first controller. The stable control of smaller liquid flow is realized by using a double-controller mode, and the flow control precision is improved.
In this specification, each embodiment is described in a progressive manner, and identical and similar parts of each embodiment are all referred to each other, and each embodiment mainly describes differences from other embodiments. In particular, for a device or device embodiment, since it is substantially similar to a method embodiment, the description is relatively simple, as relevant see the section of the method embodiment. The apparatus and apparatus embodiments described above are merely illustrative, wherein the elements described as separate elements may or may not be physically separate, and elements shown as elements may or may not be physical elements, may be located in one place, or may be distributed over a plurality of network elements. Some or all of the modules may be selected according to actual needs to achieve the purpose of the solution of this embodiment. Those of ordinary skill in the art will understand and implement the present invention without undue burden.
The previous description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the present application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the application. Thus, the present application is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.
Claims (10)
1. A method of flow control, the method comprising:
determining that the current flow rate of the liquid is greater than or equal to a first flow rate threshold value but less than a second flow rate threshold value, and driving a first controller to control a valve, wherein the valve is used for controlling the flow rate of the liquid, and the second flow rate threshold value is greater than the first flow rate threshold value;
inputting a difference result of the current flow rate of the liquid and the second flow rate threshold value to a second controller to obtain a target control parameter for controlling the first controller;
the first controller is adjusted to control the valve using the target control parameter.
2. The flow control method of claim 1, wherein the method further comprises:
determining a minimum flow detection point by a trim valve controller, the minimum flow detection point having a first flow threshold;
and taking the first flow rate threshold value with a preset multiple as the second flow rate threshold value.
3. The flow control method of claim 1, wherein the current flow rate of the liquid is determined to be less than a first flow rate threshold, the method further comprising: starting a micro flow time resolver and a PWM flow controller;
determining a closing duration of the valve using the micro flow time solver;
transmitting the closing time of the valve to the PWM flow controller, controlling the valve to be closed, and stopping the first controller;
and after the closing time of the valve is up, the current flow rate of the liquid is adjusted to the second flow rate threshold value, the first controller is started, and the PWM flow controller is closed.
4. The flow control method of claim 1, wherein the method further comprises:
acquiring the rotating speed of an impeller;
a current flow rate of the liquid is determined based on the impeller speed.
5. A flow control circuit, the flow control circuit comprising:
the system comprises a flow rate detection module, a first controller, a second controller, a flow rate threshold module, a differentiator and a valve;
the input end of the first controller is respectively connected with the output end of the flow rate detection module, the output end of the second controller and the output end of the flow rate threshold module;
the input end of the second controller is connected with the output end of the differentiator;
the input end of the differentiator is respectively connected with the output end of the flow rate detection module and the output end of the flow rate threshold module;
the output end of the first controller is connected with the input end of the valve and is used for controlling the flow of liquid through the valve.
6. The flow control circuit of claim 5, wherein the flow control circuit further comprises:
a flow recorder, a micro flow time solver and a PWM flow controller;
the input end of the flow recorder is connected with the output end of the flow velocity detection module, and the output end of the flow recorder is connected with the input end of the micro flow time resolver;
the input end of the PWM flow controller is respectively connected with the output end of the flow threshold module and the output end of the micro flow time resolver, and the output end of the PWM flow controller is connected with the input end of the valve.
7. A flow control device, the device comprising:
a driving unit, configured to determine that a current flow rate of the liquid is greater than or equal to a first flow rate threshold but less than a second flow rate threshold, and drive a first controller to control a valve, where the valve is used to control a flow rate of the liquid, and the second flow rate threshold is greater than the first flow rate threshold;
the acquisition unit is used for inputting the difference result of the current flow rate of the liquid and the second flow rate threshold value to a second controller to obtain a target control parameter for controlling the first controller;
and the control unit is used for adjusting the first controller by utilizing the target control parameter so as to control the valve.
8. The flow control device of claim 7, further comprising a first determination unit and a second determination unit:
the first determining unit is used for determining a minimum flow detection point through the fine tuning valve controller, and the minimum flow detection point is provided with a first flow threshold;
the second determining unit is configured to take the first flow rate threshold value with a preset multiple as the second flow rate threshold value.
9. The flow control device of claim 7, wherein the current flow rate of the liquid is determined to be less than a first flow rate threshold, the device further comprising: a starting unit and an adjusting unit;
the starting unit is used for starting the micro-flow time resolver and the PWM flow controller; determining a closing duration of the valve using the micro flow time solver;
the driving unit is further used for transmitting the closing time of the valve to the PWM flow controller, controlling the valve to be closed, and stopping the first controller;
and the adjusting unit is used for adjusting the current flow rate of the liquid to the second flow rate threshold value after the closing time of the valve is reached, starting the first controller and closing the PWM flow controller.
10. The flow control device of claim 7, further comprising a third determination unit:
the acquisition unit is also used for acquiring the rotating speed of the impeller;
the third determining unit is configured to determine a current flow rate of the liquid based on the impeller rotation speed.
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| Application Number | Priority Date | Filing Date | Title |
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| CN202311774621.0A CN117850484A (en) | 2023-12-21 | 2023-12-21 | Flow control method, circuit and device |
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| Application Number | Priority Date | Filing Date | Title |
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| CN202311774621.0A CN117850484A (en) | 2023-12-21 | 2023-12-21 | Flow control method, circuit and device |
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| CN202311774621.0A Pending CN117850484A (en) | 2023-12-21 | 2023-12-21 | Flow control method, circuit and device |
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