Intelligent liquid dynamic proportioning method and system based on PID closed-loop regulation

Abstract

The application provides a kind of intelligent liquid dynamic proportioning method and system based on PID closed-loop regulation, belongs to industrial automation control technical field.The method includes: obtaining target proportioning concentration and liquid preparation task parameter;Collect water supply flow, raw liquid flow and actual proportioning concentration data, generate water supply correction value according to water supply flow variation state, and carry out feedforward compensation to water supply flow;Generate basic target raw liquid flow according to compensated water supply flow, and modify basic target raw liquid flow by combining raw liquid actual output response and proportioning deviation feedback information to obtain target raw liquid flow;Control raw liquid output based on target raw liquid flow through PID closed-loop regulation.The application improves the accuracy of raw liquid flow control and the stability of proportioning concentration in the process of liquid dynamic proportioning by combining water supply state feedforward compensation, raw liquid response modification and proportioning feedback modification.

Description

Technical Field

[0001] This invention belongs to the field of industrial automation control technology, and in particular to an intelligent liquid dynamic proportioning method and system based on PID closed-loop regulation. Background Technology

[0002] In fields such as machining, cutting fluid mixing, chemical mixing, and liquid transportation, it is often necessary to continuously mix different liquids according to preset proportions to obtain a mixture that meets the requirements. For example, in machining, cutting fluid concentrate needs to be mixed with water at a set concentration, and the prepared cutting fluid needs to be continuously supplied to the machining equipment. With the development of automated machining equipment, higher demands are placed on the stable operation and automatic control capabilities of the continuous liquid mixing process.

[0003] Currently, dynamic liquid proportioning systems typically adjust the supply flow rates of different liquids according to a set proportioning relationship to achieve a continuous mixing process. Common methods include calculating proportions based on flow rate detection results and adjusting the delivery volume of corresponding liquids through actuators such as pumps and valves to achieve automatic proportioning of different component liquids. Some systems also incorporate detection feedback information to adjust the operating status during the proportioning process, thereby improving the stability of the continuous liquid proportioning process. In practical applications, the liquid proportioning process is affected by many factors, including supply conditions, pipeline conditions, actuator operating characteristics, and the detection feedback process. For example, changes in supply pressure may cause changes in liquid flow rate, the dynamic response characteristics of the delivery equipment may affect the correspondence between the actual output flow rate and the control target, and the detection feedback process also requires a certain amount of data acquisition and processing time. Therefore, dynamic liquid proportioning processes usually involve the coordinated control of multiple links, including flow rate changes, actuator adjustments, and status feedback.

[0004] With the increasing level of industrial automation, liquid dynamic proportioning systems need to dynamically adjust the proportioning process according to the actual operating conditions to adapt to changes in the state during continuous operation and improve the stability and reliability of the proportioning process. Therefore, there is an urgent need for a liquid dynamic proportioning control method that can dynamically adjust according to changes in the liquid's operating state. Summary of the Invention

[0005] This invention provides an intelligent liquid dynamic proportioning method and system based on PID closed-loop control. It aims to address the impact of changes in liquid supply status, dynamic response of actuators, and changes in proportioning status on the control of raw liquid flow rate during liquid dynamic proportioning, thereby achieving dynamic adjustment of the target flow rate of the raw liquid and improving the proportioning stability and control accuracy in the continuous liquid proportioning process.

[0006] The first aspect of this invention discloses a smart liquid dynamic proportioning method based on PID closed-loop control, comprising: S1. Obtain the target concentration ratio and solution preparation task parameters, wherein the target concentration ratio is set by the user, and the solution preparation task parameters include at least the target total solution volume and / or the target running time; S2. Obtain the water supply flow rate corresponding to the current sampling period according to the preset sampling period, and store it in the water supply flow rate sequence; S3. Calculate the water supply flow change rate and water supply flow fluctuation amplitude for the current sampling period based on the water supply flow sequence, generate the water supply correction value for the current sampling period based on the water supply flow change rate and water supply flow fluctuation amplitude, perform feedforward compensation on the water supply flow corresponding to the current sampling period based on the water supply correction value to obtain the corrected water supply flow for the current sampling period, and generate the basic target stock solution flow for the current sampling period based on the corrected water supply flow and the target ratio concentration. S4. Obtain the target stock solution flow rate and stock solution flow rate corresponding to multiple consecutive completed sampling periods. Based on the consistency of change and flow deviation between the target stock solution flow rate and the stock solution flow rate, generate the stock solution response correction value for the current sampling period. The stock solution response correction value is used to characterize the historical following response of the stock solution flow rate to the target stock solution flow rate corresponding to the sampling period, and is used to correct the basic target stock solution flow rate for the current sampling period. S5. Obtain the target stock solution flow correction value stored in the previous sampling period and the stock solution response correction value in the current sampling period, correct the basic target stock solution flow rate, and generate the target stock solution flow rate corresponding to the current sampling period. S6. Using the target stock liquid flow rate corresponding to the current sampling period as the target value of PID closed-loop regulation, control the speed or output flow rate of the servo-driven gear pump so that the stock liquid flow rate tracks the target stock liquid flow rate, obtain the stock liquid flow rate corresponding to the current sampling period, and store it in the stock liquid flow rate sequence. S7. Based on the water supply flow rate sequence and the raw liquid flow rate sequence, obtain the water supply flow rate and raw liquid flow rate corresponding to the current sampling period, calculate the actual ratio concentration of the current sampling period, and store the actual ratio concentration of the current sampling period into the actual ratio concentration sequence; obtain the actual ratio concentration of multiple consecutive sampling periods including the current sampling period in the actual ratio concentration sequence, and compare them with the target ratio concentration respectively to obtain the ratio deviation sequence; generate the ratio feedback correction parameter based on the ratio deviation sequence, wherein the ratio feedback correction parameter is used to characterize the deviation amplitude of the actual ratio concentration relative to the target ratio concentration and the stability of the ratio deviation as the sampling period changes; S8. Generate and store the target stock solution flow correction value corresponding to the current sampling period based on the ratio feedback correction parameter. The target stock solution flow correction value corresponding to the current sampling period is used to generate the target stock solution flow rate in the next sampling period. Calculate the amount of mixed solution prepared based on the sum of the water supply flow rate and the stock solution flow rate corresponding to the current sampling period. When the amount of mixed solution prepared reaches the target total amount, or the actual running time reaches the target running time, the current mixing task is completed; otherwise, proceed to the next sampling period and repeat steps S2 to S8.

[0007] A second aspect of this invention discloses an intelligent liquid dynamic proportioning system based on PID closed-loop control, characterized in that the system comprises: The task configuration module is used to obtain the target concentration ratio and solution preparation task parameters, wherein the target concentration ratio is set by the user, and the solution preparation task parameters include at least the target total solution volume and / or the target running time; The water supply detection module is used to obtain the water supply flow rate corresponding to the current sampling period according to the preset sampling period and store it in the water supply flow rate sequence; The feedforward compensation module is used to calculate the rate of change and fluctuation of water supply flow in the current sampling period based on the water supply flow sequence, generate the water supply correction value for the current sampling period based on the rate of change and fluctuation of water supply flow, perform feedforward compensation on the water supply flow corresponding to the current sampling period based on the water supply correction value to obtain the corrected water supply flow for the current sampling period, and generate the basic target stock solution flow for the current sampling period based on the corrected water supply flow and the target ratio concentration. The response correction module is used to acquire the target stock solution flow rate and stock solution flow rate corresponding to multiple consecutive completed sampling periods, and generate the stock solution response correction value for the current sampling period based on the consistency of change and flow deviation between the target stock solution flow rate and the stock solution flow rate. The stock solution response correction value is used to characterize the historical following response of the stock solution flow rate to the target stock solution flow rate corresponding to the sampling period, and is used to correct the base target stock solution flow rate for the current sampling period. The target generation module is used to obtain the target stock solution flow correction value stored in the previous sampling period and the stock solution response correction value in the current sampling period, correct the basic target stock solution flow rate, and generate the target stock solution flow rate corresponding to the current sampling period. The PID control module is used to control the speed or output flow of the servo-driven gear pump by using the target raw liquid flow rate corresponding to the current sampling period as the target value of the PID closed-loop regulation, so that the raw liquid flow rate tracks the target raw liquid flow rate, obtains the raw liquid flow rate corresponding to the current sampling period, and stores it in the raw liquid flow rate sequence. The feedback analysis module is used to obtain the water supply flow rate and raw liquid flow rate corresponding to the current sampling period based on the water supply flow rate sequence and the raw liquid flow rate sequence, calculate the actual ratio concentration of the current sampling period, and store the actual ratio concentration of the current sampling period into the actual ratio concentration sequence; obtain the actual ratio concentration of multiple consecutive sampling periods including the current sampling period in the actual ratio concentration sequence, and compare them with the target ratio concentration respectively to obtain the ratio deviation sequence; generate ratio feedback correction parameters based on the ratio deviation sequence, wherein the ratio feedback correction parameters are used to characterize the deviation amplitude of the actual ratio concentration relative to the target ratio concentration and the stability of the ratio deviation with the sampling period; The task execution module is used to generate and store the target stock solution flow rate correction value corresponding to the current sampling period based on the ratio feedback correction parameters. The target stock solution flow rate correction value corresponding to the current sampling period is used to generate the target stock solution flow rate in the next sampling period. The module calculates the amount of mixed solution prepared based on the sum of the water supply flow rate and the stock solution flow rate corresponding to the current sampling period. When the amount of mixed solution prepared reaches the target total amount, or the actual running time reaches the target running time, the current mixing task is completed. Otherwise, the module proceeds to the next sampling period and repeats the process from the water supply detection module to the task execution module.

[0008] One or more technical solutions provided in this invention have at least the following technical effects or advantages: (1) The present invention dynamically corrects the target raw liquid flow rate according to the changes in water supply status, the raw liquid execution response status and the actual mixing ratio status, so that the target raw liquid flow rate is no longer determined solely by the current water supply flow rate, but can comprehensively reflect the dynamic changes in the mixing process, thereby improving the stability of raw liquid flow rate control during continuous mixing.

[0009] (2) This invention introduces feedforward correction, raw liquid response correction and ratio feedback correction on the water supply side during the generation of target raw liquid flow rate, so that the controller can compensate for water supply disturbance, actuator response lag and ratio deviation change respectively, thereby reducing the impact of different dynamic factors on the actual ratio concentration and improving the following ability between the actual ratio concentration and the target ratio concentration.

[0010] (3) This invention uses the corrected target liquid flow rate as the control target of PID closed-loop regulation, so that the PID control process can be executed based on the target value after dynamic compensation, thereby improving the control accuracy and operation stability in the liquid dynamic proportioning process.

[0011] (4) By adopting a unified sampling period to associate and store the water supply flow, raw liquid flow and actual ratio concentration, the present invention enables the data called by different control links to have corresponding time relationships, providing a consistent data basis for water supply status analysis, execution response judgment and ratio feedback correction, and improving the data reliability of the dynamic ratio control process.

[0012] In summary, this invention constructs a dynamic generation mechanism for the target raw liquid flow rate based on water supply status analysis, execution response compensation, and ratio feedback adjustment. This enables the liquid dynamic ratio system to make real-time adjustments according to changes in the liquid state during continuous operation, reducing the impact of water supply disturbances, execution response lags, and ratio fluctuations on the ratio results, and improving the stability and ratio accuracy of the dynamic ratio process. Attached Figure Description

[0013] Figure 1 A flowchart of an intelligent liquid dynamic proportioning method based on PID closed-loop control is provided in an embodiment of the present invention; Figure 2 This is a structural diagram of an intelligent liquid dynamic proportioning system based on PID closed-loop regulation, provided in an embodiment of the present invention.

[0014] Figure labeling: Task configuration module 11, water supply detection module 12, feedforward compensation module 13, response correction module 14, target generation module 15, PID control module 16, feedback analysis module 17, task execution module 18. Detailed Implementation

[0015] like Figure 1 As shown, this invention provides an intelligent liquid dynamic proportioning method based on PID closed-loop control, which specifically includes the following steps: S1. Obtain the target concentration ratio and solution preparation task parameters, wherein the target concentration ratio is set by the user, and the solution preparation task parameters include at least the target total solution volume and / or the target running time.

[0016] Specifically, in this embodiment, the intelligent liquid dynamic proportioning method is applied to the dynamic proportioning process of cutting fluid or emulsion. Since the water supply flow rate may fluctuate during the proportioning process, the servo-driven gear pump and the raw liquid delivery pipeline exhibit response lag, and the actual proportioned concentration may continuously deviate over multiple sampling cycles, if this deviation is not corrected in time, it will accumulate in the final proportioning result cycle by cycle. Relying solely on ordinary PID closed-loop regulation of the raw liquid flow rate is insufficient to compensate for the impact of water supply disturbances, actuator response lag, and accumulated concentration deviations on proportioning accuracy. Therefore, this embodiment, based on PID closed-loop regulation, combines water supply feedforward correction, raw liquid response correction, and proportioning feedback correction to dynamically generate and correct the target raw liquid flow rate across cycles.

[0017] Before executing the solution preparation task, the controller obtains the target concentration ratio and solution preparation task parameters set by the user via the touchscreen. The target concentration ratio represents the user's desired concentration of the mixed solution. In this embodiment, the target concentration ratio represents the user's desired concentration of the mixed solution, which corresponds to the target volume ratio of the stock solution volume to the sum of the supply water volume and the stock solution volume within the sampling period. Within any sampling period, the product of the supply water flow rate and the sampling period time is the supply water volume, and the product of the stock solution flow rate and the sampling period time is the stock solution volume. This volume ratio is numerically consistent with the flow rate ratio within the same sampling period. Therefore, the ratio calculated using the supply water flow rate and stock solution flow rate corresponding to the sampling period can be used as the basis for calculating the target concentration ratio and the actual concentration ratio. After receiving the target concentration ratio, the controller stores it and uses it as a unified concentration benchmark for subsequent basic target stock solution flow rate calculation, actual concentration ratio comparison, and ratio feedback correction.

[0018] The parameters for a liquid preparation task must include at least one of the following: target total liquid volume and target running time. The target total liquid volume limits the output of the mixed liquid required for the current liquid preparation task, while the target running time limits the duration of the current liquid preparation task. When only the target total liquid volume is set, the controller uses the completion of the liquid preparation reaching the target total liquid volume as the task completion condition. When only the target running time is set, the controller uses the actual running time reaching the target running time as the task completion condition. When both the target total liquid volume and the target running time are set, the controller uses the condition that is met first, either the target total liquid volume or the target running time, as the task completion condition.

[0019] Before initiating the solution preparation task, the controller verifies the validity of the target concentration and solution preparation task parameters input by the user. If the target concentration is not input, exceeds the preset concentration range, or the target total solution volume and target running time are not set, the controller outputs an abnormal parameter prompt and waits for re-entry. When the target concentration and solution preparation task parameters meet the preset requirements, the controller confirms that the target concentration and solution preparation task parameters meet the preset requirements and then proceeds to the subsequent sampling control steps.

[0020] S2. Obtain the water supply flow rate corresponding to the current sampling period according to the preset sampling period, and store it in the water supply flow rate sequence.

[0021] Specifically, in this embodiment, the preset sampling period represents the time interval for the controller to perform one update calculation on the state of the solution preparation process, that is, the time interval between two adjacent control sampling moments. Each preset sampling period corresponds to a start time and an end time, and the controller performs periodic state updates on the solution preparation process according to the preset sampling period.

[0022] Within a preset sampling period, the controller acquires multiple water supply flow rate samples at a preset sampling frequency, and performs statistical calculations based on these samples to obtain the periodic average water supply flow rate corresponding to the preset sampling period. The water supply flow rate represents the periodic average flow rate calculated from the water supply flow rate samples within the corresponding sampling period, rather than the instantaneous water supply flow rate at a specific sampling moment. The periodic average water supply flow rate is used to characterize the average output state of the water supply side within the current preset sampling period and serves as the water supply side input parameter for subsequent water supply status analysis, basic target stock solution flow rate generation, concentration calculation, and cumulative solution volume.

[0023] Furthermore, the controller stores the calculated average water supply flow rate corresponding to the current sampling period into a water supply flow rate sequence according to the sampling time order, so that the water supply flow rate sequence records the average water supply flow rate corresponding to multiple sampling periods. When entering the next sampling period, the average water supply flow rate corresponding to the previous sampling period is used as historical water supply status data to compare with the average water supply flow rate corresponding to the current sampling period in order to calculate the rate of change and fluctuation of water supply flow rate, and generate a water supply correction value based on the trend of water supply status change.

[0024] Similarly, the controller synchronously collects the stock solution flow rate according to a preset sampling period. Within each preset sampling period, the controller acquires multiple stock solution flow rate samples at a preset sampling frequency, and calculates the periodic average stock solution flow rate value for the corresponding sampling period based on these multiple samples. The periodic average stock solution flow rate value and the periodic average water supply flow rate value are generated based on the same time period, ensuring that the water supply flow rate data and stock solution flow rate data are consistent on the time scale. This guarantees that the data used in the concentration calculation and PID closed-loop control processes correspond to the same solution preparation state.

[0025] The preset sampling period is determined based on the data output characteristics of the water supply flow meter and the rate of change of water supply disturbances. On the one hand, the preset sampling period should ensure that the flow meter can output an effective number of flow sampling data within a single sampling period, enabling the controller to calculate a stable periodic average flow value based on the multiple flow sampling values ​​acquired within the complete sampling period. On the other hand, the preset sampling period should be shorter than the main response time scale of water supply status changes, enabling the controller to promptly identify the trend of water supply flow changes and generate corresponding water supply correction values ​​before water supply disturbances significantly affect the liquid ratio, thereby reducing the ratio deviation caused by water supply fluctuations. For example, in one embodiment, the flow meter output frequency is 300–500 Hz, that is, it outputs 300–500 flow sampling signals per second. When the preset sampling period is set to 0.5 seconds, approximately 150–250 flow sampling data can be obtained within a single sampling period. The controller calculates the periodic average water supply flow value based on the above multiple flow sampling data, which can reduce the impact of single flow sampling fluctuations on the control results and improve the stability of water supply status evaluation; at the same time, the 0.5-second control update cycle can meet the requirements of rapid identification of water supply disturbances and dynamic proportioning control.

[0026] S3. Calculate the water supply flow change rate and water supply flow fluctuation amplitude for the current sampling period based on the water supply flow sequence, generate the water supply correction value for the current sampling period based on the water supply flow change rate and water supply flow fluctuation amplitude, perform feedforward compensation on the water supply flow corresponding to the current sampling period based on the water supply correction value to obtain the corrected water supply flow for the current sampling period, and generate the basic target stock solution flow for the current sampling period based on the corrected water supply flow and the target ratio concentration.

[0027] Furthermore, feedforward compensation is performed on the water supply flow rate corresponding to the current sampling period based on the water supply correction value to obtain the corrected water supply flow rate for the current sampling period, including: Obtain the water supply flow rate corresponding to the current sampling period and the water supply flow rate corresponding to multiple consecutive historical sampling periods stored in the water supply flow rate sequence, wherein the water supply flow rate represents the periodic average flow rate value calculated from the water supply flow rate sample values ​​within the corresponding sampling period. Based on the difference between the water supply flow rate corresponding to the current sampling period and the water supply flow rate corresponding to the previous sampling period, and the preset sampling period, the water supply flow rate change rate for the current sampling period is calculated. The water supply change trend corresponding to the current sampling period is determined based on the sign of the water supply flow rate change rate. Specifically, a water supply flow rate change rate greater than zero corresponds to an upward trend, a water supply flow rate change rate less than zero corresponds to a downward trend, and a water supply flow rate change rate equal to zero corresponds to a stable trend. The fluctuation range of water supply flow in the current sampling period is calculated based on the current sampling period and the difference between the maximum and minimum values ​​of water supply flow in the previous multiple consecutive sampling periods. The water supply correction value for the current sampling period is generated based on the water supply change trend and the fluctuation range of the water supply flow. Based on the water supply correction value, feedforward compensation is performed on the water supply flow corresponding to the current sampling period to obtain the corrected water supply flow corresponding to the current sampling period; The corrected water supply flow rate is used to generate the base target stock solution flow rate for the current sampling period. The base target stock solution flow rate is then corrected by the stock solution response and the ratio feedback to generate the target stock solution flow rate for the current sampling period.

[0028] Furthermore, feedforward compensation is performed on the water supply flow rate corresponding to the current sampling period based on the water supply correction value to obtain the corrected water supply flow rate corresponding to the current sampling period, including: The rate of change of water supply flow rate in the current sampling period is denoted as R. w (k) represents the fluctuation range of the water supply flow rate during the current sampling period, denoted as A. w (k), where the preset sampling period is denoted as △T; Obtain the water supply change trend corresponding to the current sampling period, and determine the water supply correction direction corresponding to the current sampling period based on the water supply change trend, wherein: When the water supply change trend is upward, the water supply correction direction is determined to be an increasing direction; When the water supply change trend is downward, the water supply correction direction is determined to be a reduction direction; When the water supply change trend is a stable trend, the water supply correction direction is determined to be the maintenance direction; According to the preset weights, |R w (k)|×△T and the fluctuation range of the water supply flow rate A w (k) is weighted to obtain the water supply compensation amplitude M(k) corresponding to the current sampling period, where M(k)≥0. The preset weight is used to characterize the influence of water supply change trend and water supply fluctuation degree on water supply correction amount. Based on the water supply correction direction and the water supply compensation amplitude M(k), the water supply correction value ΔQ corresponding to the current sampling period is generated. w (k), where: When the water supply correction direction is increasing, ΔQ w (k)=M(k); When the water supply correction direction is a decreasing direction, ΔQ w (k)=-M(k); When the water supply correction direction is the maintenance direction, ΔQ w (k)=0; According to the water supply correction value ΔQ w (k) The water supply flow rate Q corresponding to the current sampling periodw (k) Perform feedforward compensation to obtain the corrected water supply flow rate Q. w ′(k), where: Q w ′(k)=Q w (k)+ΔQ w (k); The corrected water supply flow rate Q w ′(k) is used to generate the base target original liquid flow rate for the current sampling period.

[0029] Specifically, in this embodiment, the rate of change of water supply flow is used to characterize how quickly the water supply flow changes in the current sampling period compared to the previous sampling period, and is the basis for determining whether the water supply status has changed in real time. The controller obtains the water supply flow Q corresponding to the current sampling period. w (k) and the water supply flow rate Q corresponding to the previous sampling period w (k-1), and obtain the preset sampling period ΔT. Subtract the water supply flow rate corresponding to the previous sampling period from the water supply flow rate corresponding to the current sampling period, and divide the difference by the preset sampling period to obtain the rate of change R of the water supply flow rate in the current sampling period. w (k), the calculation formula is as follows: R w (k)=(Q w (k)-Q w (k-1)) / △T; Among them, R w (k) represents the rate of change of water supply flow rate in the current sampling period relative to the previous sampling period. The sign of the rate of change of water supply flow rate determines the trend of water supply change in the current sampling period. When R w When (k) > 0, it indicates that the water supply flow rate is increasing relative to the previous sampling period; when R w When (k) < 0, it indicates that the water supply flow rate is decreasing relative to the previous sampling period; when R w When (k)=0, it indicates that the water supply flow rate remains stable relative to the previous sampling period.

[0030] In this embodiment, the fluctuation range of water supply flow is used to characterize the fluctuation range of water supply flow within multiple consecutive sampling periods, and is an important basis for judging the magnitude of flow change on the water supply side. After the water supply flow data of the current sampling period is acquired and stored in the water supply flow sequence, the controller obtains the water supply flow data corresponding to multiple consecutive sampling periods, including the current sampling period, from the water supply flow sequence. The number of sampling periods used to calculate the fluctuation range of water supply flow is denoted as n, where n≥2. The controller obtains the water supply flow data corresponding to the current sampling period and the previous n-1 consecutive sampling periods: Q w (k-n+1), Q w(k-n+2), ..., Q w (k-1), Q w (k); The maximum and minimum values ​​are determined from the above water supply flow data, and the difference between the maximum and minimum values ​​is taken as the water supply flow fluctuation range A for the current sampling period. w (k) is used to represent the fluctuation range of water supply flow over multiple consecutive sampling periods. In a specific example, n=5, that is, the fluctuation range of water supply flow is calculated using the current sampling period and the five water supply flow data corresponding to the previous four sampling periods.

[0031] The controller determines the water supply correction direction for the current sampling period based on the water supply change trend. When the water supply change trend is upward (Rw(k) > 0), the controller determines the water supply correction direction to be increasing; when the water supply change trend is downward (Rw(k) < 0), the controller determines the water supply correction direction to be decreasing; when the water supply change trend is stable (Rw(k) = 0), the controller determines the water supply correction direction to be maintaining. The water supply compensation amplitude M(k) corresponding to the current sampling period is calculated using the following formula: M(k) = α × |R w (k)|×△T+β×A w (k); Where M(k) is a non-negative value, and α and β are preset weighting coefficients. In this embodiment, α and β are preset weighting coefficients used to adjust the influence of water supply flow change and water supply flow fluctuation on the water supply compensation amplitude, respectively. α and β are determined through water supply disturbance testing during the equipment commissioning phase. To avoid the overall amplification effect of water supply flow change and water supply flow fluctuation during the weighted calculation process, this embodiment sets α and β as normalized weighting coefficients, making the sum of α and β equal to 1. Here, α is used to characterize the influence weight of single-cycle water supply change, and β is used to characterize the influence weight of multi-cycle water supply fluctuation. Specifically, during the equipment commissioning phase, by adjusting the opening of the water supply valve or changing the water supply load, different disturbance states such as increase, decrease, and periodic fluctuation of water supply flow are generated in the water supply pipeline. The water supply flow change rate, water supply flow fluctuation amplitude, and actual concentration ratio are collected for multiple consecutive sampling periods under each disturbance state. For multiple candidate weight combinations satisfying α≥0, β≥0, and α+β=1, the water supply compensation amplitude is calculated based on the corresponding candidate weight combination, and a corresponding water supply correction value is generated. The corresponding corrected water supply flow rate is obtained based on the water supply correction value, and a basic target stock solution flow rate is generated based on the corrected water supply flow rate. The solution preparation process is executed, and the actual concentration change process corresponding to each candidate weight combination is obtained. Further, the deviation between the actual concentration and the target concentration corresponding to each candidate weight combination is compared, including the average absolute value, maximum absolute value, and deviation recovery time of the actual concentration deviation. Based on the above evaluation indicators, each candidate weight combination is comprehensively ranked, and the candidate weight combination with the smaller actual concentration deviation, lower maximum deviation, and shorter deviation recovery time is selected as the preset weight coefficient and stored in the controller. Specifically, priority is given to candidate weight combinations that require a shorter time to recover the actual concentration deviation to near the target concentration. When the deviation recovery times of multiple candidate weight combinations are similar, their average deviations of actual concentration are further compared, and the candidate weight combination with the smaller average deviation is selected. When the average deviations of actual concentration are also similar, their maximum deviations of actual concentration are further compared, and the candidate weight combination with the smaller maximum deviation is selected.

[0032] The controller generates the water supply correction value ΔQ corresponding to the current sampling period based on the water supply correction direction and the water supply compensation amplitude M(k). w (k). When the water supply correction direction is increasing: ΔQ w (k)=M(k); When the water supply correction direction is the decreasing direction: ΔQ w (k)=-M(k); When the water supply correction direction is the maintenance direction: ΔQ w (k)=0. The controller is based on the water supply correction value ΔQ. w (k) The water supply flow rate Q corresponding to the current sampling period w(k) Perform feedforward compensation to obtain the corrected water supply flow rate Q. w ′(k), the formula is as follows: Q w ′(k)=Q w (k)+ΔQ w (k); Among them, the corrected water supply flow rate Q w ′(k) is the flow parameter calculated by the controller based on the water supply change trend and the fluctuation range of the water supply flow rate after compensation on the water supply side. Feedforward compensation is used to pre-correct the impact of water supply disturbance factors on the demand for raw materials when generating the target raw material flow rate, rather than changing the actual water supply state of the water supply pipeline.

[0033] During the dynamic proportioning of liquids, the water flow rate in the water supply pipeline may be affected by factors such as changes in water supply pressure, valve adjustment actions, and changes in pipeline operating status, causing the water flow rate to change or fluctuate between different sampling periods. If the controller only generates the basic target stock solution flow rate according to a fixed ratio based on the water flow rate corresponding to the current sampling period, it cannot consider the impact of water flow rate change trends on the stock solution demand in advance, which can easily lead to a response lag between the adjustment of the target flow rate on the stock solution side and the changes on the water supply side. This embodiment uses the water flow rate change rate to characterize the trend and degree of change of the water flow rate in the current sampling period relative to the previous sampling period, and uses the water flow rate fluctuation amplitude to characterize the fluctuation range of the water flow rate within multiple consecutive sampling periods, enabling the controller to simultaneously acquire the single-period change characteristics and multi-period fluctuation characteristics of the water supply side. Based on the water flow change trend and the water flow rate fluctuation amplitude, a water supply correction value is generated, and feedforward compensation is performed on the water flow rate corresponding to the current sampling period based on the water supply correction value to obtain the corrected water flow rate. The corrected water supply flow rate does not represent an adjustment to the actual output flow rate of the water supply pipeline. Instead, it serves as a corrected input parameter on the water supply side when generating the basic target stock solution flow rate. This parameter is used to preemptively correct the impact of water supply disturbances on the calculated stock solution demand. Through this method, before the PID closed-loop adjustment of the stock solution flow rate, the controller performs feedforward correction on the basic target stock solution flow rate based on the changing trend of the water supply side. This allows the stock solution control target to adapt to changes in water supply disturbances in advance. Combined with subsequent stock solution response correction and proportioning feedback correction, this improves the ability of the actual proportioning concentration to follow the target proportioning concentration during dynamic proportioning, reducing periodic proportioning deviations caused by changes in water supply flow rate.

[0034] Furthermore, the baseline target stock solution flow rate for the current sampling period is generated based on the corrected water supply flow rate and the target concentration ratio, including: The target concentration ratio is denoted as C. t The C t This indicates the target volume ratio of the original solution in the mixture; Calculate the target flow ratio coefficient K cThe formula is as follows: K c =C t / (1-C t ); Based on the corrected water supply flow rate Q corresponding to the current sampling period w ′(k) and the target flow rate proportionality coefficient K c Calculate the baseline target original liquid flow rate Q for the current sampling period. o 0(k), the formula is as follows: Q o 0(k)=K c ×Q w ′(k); The basic target stock solution flow rate is the initial target stock solution flow rate calculated based on the corrected water supply flow rate and target ratio concentration corresponding to the current sampling period, and is used for stock solution response correction and ratio feedback correction.

[0035] Specifically, in this embodiment, the controller obtains the corrected water supply flow rate Q for the current sampling period. w After (k), the base target stock solution flow rate for the current sampling period is generated based on the user-defined target concentration ratio. The corrected water supply flow rate Q is then calculated. w ′(k) is obtained from the aforementioned water supply feedforward compensation step and is the water supply side correction input used by the controller when calculating the basic target raw liquid flow rate.

[0036] The controller records the target concentration as C. t In this embodiment, C t This indicates the target volume ratio of the stock solution in the mixture formed by the water supply and the stock solution, as set by the user. Since the water supply flow rate and stock solution flow rate are proportional to the water supply volume and stock solution volume, respectively, within the same sampling period, the volume ratio corresponding to the target concentration can be converted into the corresponding flow ratio when the sampling period is consistent. When the user-input target concentration is in percentage form, the controller converts the percentage to a decimal form and uses it as C. t .

[0037] Since the water supply flow rate and the raw liquid flow rate are expressed using the periodic average flow rate corresponding to the same sampling period, they have the same flow dimension and can therefore be directly used to calculate the flow ratio relationship corresponding to the target concentration. The controller corrects the water supply flow rate Q. w ′(k) is used as the water supply-side input for the target calculation, and is based on the basic target raw liquid flow rate Q. o 0(k) is the theoretical flow rate of the stock solution at the target concentration, and the formula is as follows: C t =Q o 0(k) / (Q w ′(k)+Qo 0(k)); Transforming the above equation, we get: ; Therefore, the controller calculates the target flow proportionality coefficient K. c :K c =C t / (1-C t And based on the corrected water supply flow rate Q of the current sampling period. w ′(k) calculates the base target original liquid flow rate Q for the current sampling period. o 0(k), the formula is as follows: Q o 0(k)=K c ×Q w ′(k); Among them, Q o 0(k) represents the base target stock solution flow rate for the current sampling period. The base target stock solution flow rate is the initial target stock solution flow rate calculated based on the corrected water supply flow rate and target ratio concentration corresponding to the current sampling period. It is used for stock solution response correction and ratio feedback correction.

[0038] It should be noted that the baseline target stock solution flow rate is not the final target stock solution flow rate used for PID closed-loop regulation. In subsequent steps, the controller will combine the stock solution response correction value of the current sampling period with the target stock solution flow rate correction value stored in the previous sampling period to correct the baseline target stock solution flow rate, thereby generating the target stock solution flow rate for the current sampling period. Therefore, the baseline target stock solution flow rate serves as the initial calculation basis for the target stock solution flow rate generation process, rather than directly replacing the target value for the stock solution-side PID closed-loop regulation.

[0039] Through the above processing, the controller can convert the user-set target concentration ratio into a target flow rate ratio coefficient and calculate the basic target raw material flow rate based on the corrected water supply flow rate. This process connects the target concentration ratio, the water supply feedforward compensation result, and the raw material target flow rate generation process, so that the water supply feedforward compensation, raw material response correction, and ratio feedback correction act on different influencing factors in the target raw material flow rate generation process, thereby forming a hierarchical correction mechanism for generating the target raw material flow rate.

[0040] S4. Obtain the target stock solution flow rate and stock solution flow rate corresponding to multiple consecutive completed sampling periods. Based on the consistency of change and flow deviation between the target stock solution flow rate and the stock solution flow rate, generate the stock solution response correction value for the current sampling period. The stock solution response correction value is used to characterize the historical following response of the stock solution flow rate to the target stock solution flow rate for the sampling period, and is used to correct the base target stock solution flow rate for the current sampling period. In the first sampling period, a preset stock solution response correction value is used.

[0041] Furthermore, based on the consistency of the change between the target stock solution flow rate and the stock solution flow rate, as well as the flow rate deviation, a stock solution response correction value for the current sampling period is generated, including: Obtain the target stock solution flow rate and the corresponding stock solution flow rate for a series of consecutive completed sampling cycles stored before the current sampling cycle, wherein the number of the series of consecutive completed sampling cycles is not less than two; Based on the difference between the target stock liquid flow rate and the corresponding stock liquid flow rate for each completed sampling cycle, a stock liquid flow rate deviation sequence is generated, and the average deviation is calculated based on the stock liquid flow rate deviation sequence. Based on the magnitude relationship between the target stock solution flow rates corresponding to adjacent completed sampling cycles, the direction of change of the target stock solution flow rate corresponding to each adjacent sampling cycle is determined. Based on the magnitude relationship between the stock solution flow rates corresponding to adjacent completed sampling cycles, the direction of change of the stock solution flow rate corresponding to each adjacent sampling cycle is determined. The number of times the direction of change of the target stock solution flow rate is consistent with the direction of change of the stock solution flow rate is counted to obtain the number of times the direction of change is consistent. Based on the number of times the direction of change is consistent, the degree of inconsistency in the response is determined. The direction of change of the target stock solution flow rate and the direction of change of the stock solution flow rate both include the direction of increase, the direction of decrease, and the direction of no change. The direction of original solution response correction corresponding to the current sampling period is determined based on the average deviation, wherein: When the average deviation is greater than zero, the direction of the original solution response correction is determined to be the increasing direction; When the average deviation is less than zero, the direction of the original solution response correction is determined to be the reduction direction; When the average deviation is equal to zero, the original solution response correction direction is determined to be the maintenance direction; The basic response correction amount is determined based on the absolute value of the average deviation. The additional response correction amount is determined based on the degree of response inconsistency and the average target original liquid flow rate corresponding to the completed sampling period. The basic response correction amount and the additional response correction amount are superimposed to obtain the original liquid response correction amount corresponding to the current sampling period. The sign corresponding to the original liquid response correction direction and the original liquid response correction amount are combined to generate the original liquid response correction value corresponding to the current sampling period. The original liquid response correction value is used to characterize the flow deviation and change following consistency of the original liquid flow rate relative to the target original liquid flow rate within multiple consecutive completed sampling periods, so as to reflect the historical following response of the original liquid flow rate to the target original liquid flow rate, and is used to correct the basic target original liquid flow rate of the current sampling period.

[0042] Specifically, in this embodiment, a correction value for the stock solution response corresponding to the current sampling period is generated based on the following relationship between the target stock solution flow rate and the actual stock solution flow rate within the completed sampling period. Within each sampling period, the controller associates and stores the target stock solution flow rate and the actually detected stock solution flow rate for that sampling period. When data from multiple consecutive completed sampling periods has been stored before the current sampling period, the controller acquires the target stock solution flow rate and stock solution flow rate corresponding to those multiple consecutive completed sampling periods. The number of consecutive completed sampling periods is denoted as L, and L≥2. When L=2, the controller determines the consistency of the change direction based solely on the change relationship between one adjacent sampling period.

[0043] Let Q be the target original liquid flow rate corresponding to the i-th completed sampling cycle. o t(i), the corresponding original liquid flow rate is denoted as Q. r (i) The controller generates a raw liquid flow deviation sequence based on the difference between the target raw liquid flow rate and the raw liquid flow rate: E(i)=Q o t(i)-Q r E(i) represents the deviation of the stock solution flow rate relative to the target stock solution flow rate within the i-th completed sampling period. The controller calculates the average deviation based on the stock solution flow rate deviations corresponding to multiple consecutive completed sampling periods: ; average deviation It is used to characterize the overall deviation direction and degree of the actual stock solution flow rate relative to the target stock solution flow rate within multiple consecutive completed sampling periods.

[0044] The controller is based on the average deviation. Determine the direction of the original solution response correction corresponding to the current sampling period: when When the actual stock solution flow rate is consistently lower than the target stock solution flow rate, the controller determines the stock solution response correction direction to be the increasing direction. when When the actual raw liquid flow rate is consistently higher than the target raw liquid flow rate, the controller determines the raw liquid response correction direction to be the reduction direction. when At that time, the controller determines the original liquid response correction direction as the hold direction.

[0045] The controller is based on the absolute value of the average deviation. Generate the base correction M for the current sampling period b (k), Basic correction amount M b(k) is used to compensate for the steady-state error caused by the long-term deviation of the raw liquid flow rate from the target value. Its magnitude is determined by the amplitude of the historical average deviation. Further, the controller determines the degree of consistency between the target raw liquid flow rate change direction and the raw liquid flow rate change direction based on the target raw liquid flow rate changes in adjacent completed sampling periods and the corresponding raw liquid flow rate changes. Specifically, when the target raw liquid flow rate in the later sampling period is greater than that in the previous sampling period, the target raw liquid flow rate change direction is determined to be increasing; when it is less, it is determined to be decreasing; and when they are equal, it is determined to be unchanged. The raw liquid flow rate change direction is determined in the same way. The controller counts the number of times the target raw liquid flow rate change direction is consistent with the raw liquid flow rate change direction in multiple consecutive adjacent sampling periods, obtaining the number of times the change direction is consistent, N. c (k), and based on the number of times N is consistent with the direction of change. c (k) Determine the degree of inconsistency in the response S r (k): Where L represents the number of sampling periods that have been completed, and S r (k) is used to characterize the degree of inconsistency in the response of the raw liquid flow rate to changes in the target raw liquid flow rate. The fewer the number of times the change direction is consistent, the lower the S value. r The larger (k) is, the weaker the ability of the actual stock solution flow rate to follow changes in the target stock solution flow rate. The controller acquires the target stock solution flow rate Q corresponding to multiple consecutive completed sampling cycles. o The average value of t(i): The degree of inconsistency in the response S r (k) and the average value of the target original liquid flow rate Multiplying them together yields the additional correction M for the current sampling period. a (k): ; Additional correction amount M a (k) is used to determine the equivalent dynamic compensation flow rate that matches the current feedstock delivery scale, based on the degree to which the feedstock flow rate fails to keep up with changes in the target feedstock flow rate. Specifically, S r (k) Dimensionless parameter used to represent the proportion of the target stock solution flow rate change that is not correctly followed by the actual stock solution flow rate within multiple consecutive completed sampling periods; The value represents the average flow rate of the target concentrate within the corresponding historical sampling period, used to reflect the flow rate scale in the current concentrate delivery process. Multiplying these two values ​​maps the underperformance ratio to a dynamic compensation amount with flow rate dimensions based on the current concentrate delivery scale. When the overall target concentrate flow rate is large, the same degree of underperformance corresponds to a larger equivalent flow rate compensation requirement; conversely, when the overall target concentrate flow rate is small, the same degree of underperformance corresponds to a smaller equivalent flow rate compensation requirement.

[0046] The controller will adjust the base correction amount M b (k) and additional correction Ma (k) superposition yields the original liquid response correction amount M corresponding to the current sampling period. r (k): M r (k)=M b (k)+M a (k); The raw material response correction takes into account both historical flow deviation and insufficient dynamic response on the generation of the target raw material flow. As a correction step in the generation of the target raw material flow, the raw material response correction adds a correction to the basic target raw material flow, so that the target raw material flow already includes the historical response characteristics of the raw material side before entering the subsequent ratio feedback correction.

[0047] The controller corrects the direction and amount of the original liquid response based on the original liquid response. r (k) generates the original liquid response correction value ΔQ corresponding to the current sampling period. r (k), where: When the original solution response correction direction is increasing: ΔQ r (k)=M r (k); When the original solution response correction direction is the decreasing direction: ΔQ r (k)=-M r (k); When the original solution response correction direction is the maintenance direction: ΔQ r (k)=0.

[0048] The stock solution response correction value is used to characterize the deviation of the stock solution flow rate from the target stock solution flow rate and the consistency of change tracking over multiple consecutive completed sampling periods, and is used to correct the base target stock solution flow rate. In the first sampling period or when the number of completed sampling periods is less than two, the controller sets the stock solution response correction value to zero. Since historical data for evaluating the tracking relationship between the target stock solution flow rate and the actual stock solution flow rate is lacking at this time, no stock solution response compensation is performed.

[0049] S5. Obtain the target stock solution flow correction value stored in the previous sampling period and the stock solution response correction value in the current sampling period, correct the basic target stock solution flow rate, and generate the target stock solution flow rate corresponding to the current sampling period; wherein, in the first sampling period, the target stock solution flow correction value is set to zero.

[0050] Further, the target stock solution flow rate correction value stored in the previous sampling period and the stock solution response correction value in the current sampling period are obtained, and the basic target stock solution flow rate is corrected to generate the target stock solution flow rate for the current sampling period, including: Obtain the target original liquid flow correction value ΔQ stored in the previous sampling period. f (k-1), the base target original liquid flow rate Q in the current sampling period.o 0(k), the original liquid response correction value ΔQ for the current sampling period. r (k); Based on the aforementioned basic target original liquid flow rate Q o 0(k), the original solution response correction value ΔQ r (k) and the target original liquid flow rate correction value ΔQ f (k-1), generate the target original liquid flow rate Q for the current sampling period. o t(k), the formula is as follows: Q o t(k) = Q o 0(k)+ΔQ r (k)+ΔQ f (k-1); Wherein, the target original liquid flow rate Q o t(k) is used as the target value of the PID closed-loop regulation in the current sampling period to control the servo-driven gear pump to perform raw liquid flow regulation.

[0051] Specifically, in this embodiment, the controller generates the target stock solution flow rate for the current sampling period based on the baseline target stock solution flow rate, the stock solution response correction value, and the target stock solution flow rate correction value stored in the previous sampling period. The baseline target stock solution flow rate is denoted as Q. o 0(k), the original solution response correction value is denoted as ΔQ r (k), the target original liquid flow rate correction value stored in the previous sampling period is denoted as ΔQ. f (k-1). Basic target stock solution flow rate Q o 0(k) is calculated based on the corrected water supply flow rate corresponding to the current sampling period and the target concentration ratio set by the user. It is used to characterize the initial raw material demand flow rate corresponding to the current sampling period under the constraint of the target concentration ratio ratio. The raw material response correction value ΔQ r (k) Determined based on the deviation between the target concentrate flow rate and the concentrate flow rate over multiple consecutive completed sampling periods, and the consistency of change tracking; used to compensate for the response lag generated during dynamic adjustment of the concentrate delivery mechanism, actuator, and flow detection circuit. The target concentrate flow rate correction value is ΔQ. f (k-1) is generated and stored based on the deviation between the actual concentration and the target concentration in the previous sampling period, and is used to compensate for the cross-sampling period deviation generated during the feedback of the proportioning results.

[0052] During the generation of the target stock solution flow rate in the current sampling period, the controller acquires the above three target generation quantities and generates the target stock solution flow rate Q for the current sampling period. o t(k): Q o t(k) = Q o 0(k)+ΔQr (k)+ΔQ f (k-1). Basic target stock solution flow rate Q o 0(k) provides the basic requirement for generating the current target feedstock flow rate; feedstock response correction value ΔQ r (k) is used to pre-correct the basic demand based on the historical response characteristics of the raw material side; the target raw material flow rate correction value ΔQ f (k-1). Used to adjust the current target value based on the actual mixing ratio result of the previous sampling period. Therefore, the three target generation quantities correspond to three different levels of influencing factors: target mixing ratio calculation, raw material execution response, and mixing result feedback. The target raw material flow rate obtained after superposition is not a single proportional calculation result based on the water supply flow rate, but a comprehensive control target generated by further combining the raw material response characteristics and mixing ratio feedback results on the basis of water supply feedforward compensation. It should be noted that the basic target raw material flow rate, raw material response correction value, and target raw material flow rate correction value correspond to three different influencing factors: water supply side state change, raw material execution response deviation, and actual mixing ratio result deviation. By superimposing the correction quantities from the above different sources into the basic target raw material flow rate, the target raw material flow rate generated in the current sampling period simultaneously includes water supply side disturbance compensation, raw material side response compensation, and mixing ratio result feedback compensation, thereby avoiding the inability to adapt to the actual deviations in the dynamic operation process when determining the target raw material flow rate based solely on the water supply flow rate and target mixing ratio concentration.

[0053] In the first sampling period, since the target stock solution flow rate correction value stored in the previous sampling period is not available, the controller will use the target stock solution flow rate correction value ΔQ. f (k-1) is set to zero; meanwhile, since multiple consecutive completed sampling cycles of original liquid response data have not yet been generated, the controller uses the preset original liquid response correction value as ΔQ. r (k), in one embodiment, the preset original liquid response correction value is zero.

[0054] The controller will generate the target original liquid flow rate Q o t(k) serves as the target value for the PID closed-loop adjustment in the current sampling period. The operating state of the servo-driven gear pump is adjusted based on the deviation between the target raw liquid flow rate and the actual raw liquid flow rate, ensuring that the raw liquid flow rate tracks the target raw liquid flow rate. It should be noted that the target raw liquid flow rate provides the target input for the PID closed-loop adjustment, while the PID closed-loop adjustment itself is dynamically adjusted based on the raw liquid flow rate feedback. Therefore, the target raw liquid flow rate generation process improves the accuracy of the PID adjustment target, while the PID closed-loop adjustment achieves flow tracking during execution; both together enhance the control stability during the dynamic mixing process.

[0055] S6. Using the target stock solution flow rate corresponding to the current sampling period as the target value for PID closed-loop regulation, control the speed or output flow rate of the servo-driven gear pump so that the stock solution flow rate tracks the target stock solution flow rate, obtain the stock solution flow rate corresponding to the current sampling period, and store it in the stock solution flow rate sequence.

[0056] Specifically, in this embodiment, the controller generates the target stock solution flow rate Q corresponding to the current sampling period. o After t(k), the target stock solution flow rate is used as the target value for the PID closed-loop regulation on the stock solution side. Specifically, the controller sends the target stock solution flow rate corresponding to the current sampling period to the PID control module. The PID control module obtains the actual stock solution flow rate corresponding to the current sampling period collected by the stock solution flow rate detection unit. The actual stock solution flow rate is the stock solution flow rate corresponding to the current sampling period. Based on the deviation between the target stock solution flow rate and the stock solution flow rate, the controller generates a control quantity for the servo-driven gear pump to adjust the speed or output flow rate of the servo-driven gear pump, so that the stock solution flow rate tracks the target stock solution flow rate.

[0057] Let the current sampling period be denoted as the kth sampling period, and let the target original liquid flow rate corresponding to the current sampling period be denoted as Q. o t(k) is the original liquid flow rate corresponding to the current sampling period, denoted as Q. r (k). Where Q o t(k) is the setpoint for the PID closed-loop control, Q r (k) serves as the feedback value for PID closed-loop regulation. The controller obtains the original liquid flow rate Q corresponding to the current sampling period. r After (k), the stock solution flow rate is stored in the stock solution flow rate sequence according to the sampling time, and the target stock solution flow rate Q corresponding to the current sampling period is set. o t(k) and original liquid flow rate Q r (k) Associative storage. Through the above method, the controller can obtain the target stock solution flow rate and actual stock solution flow rate corresponding to multiple consecutive completed sampling cycles, providing a data basis for subsequently generating stock solution response correction values ​​based on stock solution flow rate deviation and consistency of change tracking. In this embodiment, the target stock solution flow rate generation process is used to generate a PID control target suitable for the current operating conditions based on water supply disturbances, stock solution response characteristics, and proportioning deviations. The PID closed-loop regulation is used to control the stock solution-side actuator to achieve tracking output of the target stock solution flow rate. Both act on the target generation layer and the execution control layer respectively, jointly realizing stock solution flow rate adjustment during the dynamic proportioning process.

[0058] S7. Based on the water supply flow rate sequence and the raw liquid flow rate sequence, obtain the water supply flow rate and raw liquid flow rate corresponding to the current sampling period, calculate the actual ratio concentration of the current sampling period, and store the actual ratio concentration of the current sampling period into the actual ratio concentration sequence; obtain the actual ratio concentration of multiple consecutive sampling periods in the actual ratio concentration sequence, and compare them with the target ratio concentration respectively to obtain the ratio deviation sequence; generate the ratio feedback correction parameter based on the ratio deviation sequence, wherein the ratio feedback correction parameter is used to characterize the deviation amplitude of the actual ratio concentration relative to the target ratio concentration and the stability of the ratio deviation as the sampling period changes.

[0059] Furthermore, the actual concentration ratio for the current sampling period is calculated, including: Obtain the water supply flow rate Q corresponding to the current sampling period. w (k), and the original liquid flow rate Q corresponding to the current sampling period. r (k), where the original liquid flow rate represents the periodic average flow rate value calculated from the original liquid flow rate sampling values ​​within the corresponding sampling period, and the actual proportion concentration C of the current sampling period is calculated. a (k), the formula is as follows: C a (k)=Q r (k) / (Q w (k)+Q r (k)); Wherein, the actual concentration ratio C a (k) represents the actual ratio result formed by the water supply flow rate and the original liquid flow rate corresponding to the current sampling period, which is used to characterize the actual ratio state of the current sampling period; The actual concentration ratio C a (k) Store the actual ratio concentration sequence in the order of sampling time. The actual ratio concentration sequence is used to obtain the actual ratio concentration corresponding to multiple consecutive sampling periods in order to generate ratio feedback correction parameters.

[0060] Furthermore, generating proportion feedback correction parameters based on the proportion deviation sequence includes: Obtain the actual ratio concentration of the actual ratio concentration in the actual ratio concentration sequence, including the current sampling period, for a continuous multiple sampling periods, wherein the number of the continuous multiple sampling periods is not less than two; The actual concentration ratio corresponding to each sampling period is compared with the target concentration ratio, and the concentration ratio ratio is obtained by subtracting the actual concentration ratio from the target concentration ratio. A concentration ratio ratio ratio deviation sequence is generated according to the sampling time sequence. The average value of the ratio deviation is obtained by averaging the ratio deviations in the ratio deviation sequence. The fluctuation range of the proportion deviation is obtained by the difference between the maximum and minimum proportion deviations in the proportion deviation sequence. The representative value of the ratio deviation and the fluctuation range of the ratio deviation are used as the ratio feedback correction parameters; The ratio deviation representative value is used to characterize the direction and magnitude of the deviation of the actual ratio concentration from the target ratio concentration within multiple consecutive sampling periods, and the ratio deviation fluctuation amplitude is used to characterize the degree of fluctuation of the ratio deviation within multiple consecutive sampling periods.

[0061] Specifically, in this embodiment, the controller calculates the actual concentration ratio for the current sampling period based on the water supply flow rate and the raw liquid flow rate corresponding to the current sampling period. The water supply flow rate for the current sampling period comes from the water supply flow rate sequence, and the raw liquid flow rate for the current sampling period comes from the raw liquid flow rate sequence. Both have the same sampling period identifier, thus reflecting the actual flow status of the water supply side and the raw liquid side within the same sampling period. The water supply flow rate for the current sampling period is denoted as Q. w (k), where Q is the original liquid flow rate corresponding to the current sampling period. r (k), calculate the actual concentration C corresponding to the current sampling period. a (k): C a (k)=Q r (k) / (Q w (k)+Q r (k)); where C a (k) represents the actual concentration ratio corresponding to the current sampling period, which is used to characterize the proportion of the original liquid flow rate to the total mixed flow rate formed by the water supply flow rate and the original liquid flow rate within the current sampling period.

[0062] In this embodiment, since the water supply medium and the stock solution are continuously transported through corresponding pipelines during the dynamic mixing process, and the target mixing concentration corresponds to the ratio of the stock solution volume to the total volume of the mixed solution, the ratio between the stock solution flow rate and the total mixed flow rate is used as the actual mixing concentration for the current sampling period. Because Q w (k) and Q r (k) are all flow data collected within the same sampling period, therefore, the C calculated above... a (k) can reflect the actual ratio status of the current sampling period.

[0063] The controller will set the actual concentration C corresponding to the current sampling period. a(k) Store the actual concentration ratios in the sampling time sequence. As the solution preparation process continues, the actual concentration ratio sequence stores the actual concentration ratios corresponding to multiple sampling periods sequentially, used to analyze the continuous deviation of the actual concentration ratio from the target concentration ratio. When generating the ratio feedback correction parameter, the controller obtains the actual concentration ratios corresponding to multiple consecutive sampling periods, including the current sampling period, from the actual concentration ratio sequence, where the number of consecutive sampling periods is denoted as N, and N≥2. The controller compares the actual concentration ratio corresponding to each sampling period with the target concentration ratio, subtracts the actual concentration ratio from the target concentration ratio to obtain the ratio deviation corresponding to each sampling period, and generates a ratio deviation sequence in the sampling time sequence. The actual concentration ratio corresponding to the i-th sampling period is denoted as C. a (i) The target concentration is denoted as C. t The ratio deviation corresponding to the i-th sampling period is denoted as: E c (i)=C t -C a (i); where, E c (i) represents the deviation of the actual concentration from the target concentration within the i-th sampling period. When the concentration deviation E c (i) When it is positive, it indicates that the actual concentration is lower than the target concentration; when the concentration deviation E c (i) When it is negative, it indicates that the actual concentration ratio is higher than the target concentration ratio; when the concentration ratio deviation E c (i) When it is zero, it means that the actual concentration ratio is consistent with the target concentration ratio.

[0064] The controller calculates the representative value of the proportion deviation by averaging the proportion deviations in the proportion deviation sequence, as shown in the following formula: Among them, the representative value of the proportion deviation It is used to characterize the overall deviation direction and average deviation magnitude of the actual concentration relative to the target concentration over multiple consecutive sampling periods.

[0065] Furthermore, the controller obtains the maximum and minimum proportion deviation values ​​in the proportion deviation sequence, and calculates the proportion deviation fluctuation range based on the difference between the two: Among them, E cmax (k) represents the maximum value in the ratio deviation sequence over multiple consecutive sampling periods, E cmin(k) represents the minimum value in the ratio deviation sequence within multiple consecutive sampling periods. The ratio deviation fluctuation amplitude is used to characterize the range of variation in the actual ratio concentration deviation within multiple consecutive sampling periods. When the ratio deviation fluctuation amplitude is small, it indicates that the actual ratio concentration deviation is relatively stable; when the ratio deviation fluctuation amplitude is large, it indicates that the actual ratio concentration deviation fluctuates significantly. The controller uses both the ratio deviation representative value and the ratio deviation fluctuation amplitude as the ratio feedback correction parameters corresponding to the current solution preparation process. The ratio deviation representative value characterizes the direction and degree of continuous deviation of the actual ratio concentration relative to the target ratio concentration, and is used to determine the correction direction of the subsequent target stock solution flow rate; the ratio deviation fluctuation amplitude characterizes the stability of the ratio deviation as it changes with the sampling period, and is used to reflect the concentration adjustment stability of the current solution preparation process. In practical applications, the controller generates the target stock solution flow rate correction value for the next sampling period based on the ratio feedback correction parameters, and stores the target stock solution flow rate correction value for use in the target stock solution flow rate generation process of subsequent sampling periods. When the number of sampling periods stored in the actual concentration sequence is less than two, the controller does not generate a ratio feedback correction parameter because it is impossible to form a ratio deviation sequence corresponding to multiple consecutive sampling periods, and sets the corresponding target original liquid flow correction value to zero.

[0066] S8. Generate and store the target stock solution flow correction value corresponding to the current sampling period based on the ratio feedback correction parameter. The target stock solution flow correction value corresponding to the current sampling period is used to generate the target stock solution flow rate in the next sampling period. Calculate the amount of mixed solution prepared based on the water supply flow rate and stock solution flow rate corresponding to the current sampling period. When the amount of mixed solution prepared reaches the target total amount, or the actual running time reaches the target running time, the current mixing task is completed; otherwise, proceed to the next sampling period and repeat steps S2 to S8.

[0067] Furthermore, based on the ratio feedback correction parameters, a target stock solution flow rate correction value corresponding to the current sampling period is generated and stored, including: Obtain the representative value of the ratio deviation and the fluctuation range of the ratio deviation from the ratio feedback correction parameters; The direction of ratio feedback correction is determined based on the representative value of the ratio deviation, wherein: When the representative value of the ratio deviation is greater than zero, the ratio feedback correction direction is determined to be the increasing direction; When the representative value of the ratio deviation is less than zero, the ratio feedback correction direction is determined to be the reduction direction; When the representative value of the ratio deviation is equal to zero, the ratio feedback correction direction is determined to be the maintenance direction; The basic feedback correction amount is determined based on the absolute value of the representative value of the ratio deviation. The stability additional correction amount is determined based on the fluctuation range of the ratio deviation and the average water supply flow rate corresponding to multiple consecutive sampling periods that form the ratio deviation sequence. The basic feedback correction amount and the stability additional correction amount are superimposed to obtain a non-negative ratio feedback correction amount. The sign corresponding to the ratio feedback correction direction and the ratio feedback correction amount are combined to generate the target original liquid flow rate correction value ΔQ corresponding to the current sampling period. f (k), where: When the ratio feedback correction direction is increasing, the target original liquid flow rate correction value is positive; When the direction of the ratio feedback correction is a decrease, the target original liquid flow rate correction value is negative; When the ratio feedback correction direction is the maintenance direction, the target original liquid flow rate correction value is zero. The target original liquid flow rate correction value ΔQ f (k) Stored in the order of sampling time for use when generating the target stock solution flow rate in the next sampling cycle.

[0068] Specifically, in this embodiment, after generating the ratio feedback correction parameters, the controller generates a target stock solution flow rate correction value corresponding to the current sampling period based on the ratio feedback correction parameters. The ratio feedback correction parameters include a representative value of the ratio deviation. and the fluctuation range of the ratio deviation The controller uses the representative value of the proportion deviation. Determine the direction of the ratio feedback correction corresponding to the current sampling period. When When the actual concentration is lower than the target concentration, the flow rate of the original solution needs to be increased to improve the concentration. The controller determines the direction of the ratio feedback correction to be increased. When the actual concentration is higher than the target concentration, the flow rate of the original solution needs to be reduced to lower the concentration. The controller determines the direction of the ratio feedback correction to be reduction. At that time, the controller determines that the ratio feedback correction direction is the maintain direction.

[0069] The controller is based on the absolute value of the proportion deviation. Determine the basic feedback correction amount. Representative value of the proportioning deviation. The concentration deviation value is dimensionless, while the target stock solution flow rate correction value needs to maintain the same flow rate dimension as the baseline target stock solution flow rate; therefore, dimension conversion is required. The controller acquires the average water supply flow rate corresponding to multiple consecutive sampling periods that form the proportioning deviation sequence. : Where N is the number of sampling periods for forming the proportioning deviation sequence, and the range of the sampling periods is consistent with the range for generating the proportioning deviation sequence, both from the (k-N+1)th sampling period to the current sampling period k, including the current sampling period, Q w (i) represents the water supply flow rate of the i-th corresponding element.

[0070] According to the definition of concentration ratio, the concentration ratio represents the proportion of the stock solution flow rate to the total flow rate. When the water supply flow rate is constant, changes in the concentration ratio need to be achieved by adjusting the stock solution flow rate, and this adjustment amount is related to the current water supply flow rate level. Therefore, this embodiment uses a concentration deviation ratio... Perform flow rate scaling and then multiply by the average water supply flow rate. The basic feedback correction amount M is obtained. c_base (k) When the target concentration variation range is small and the water supply flow rate is the main source of disturbance, the concentration deviation can be converted into the corresponding raw material flow rate adjustment under the water supply conditions through the above proportional relationship. The basis for this conversion is that the representative value of the proportion deviation is based on the concentration ratio deviation, which reflects the proportional deviation between the raw material flow rate and the total flow rate. When converting it into the correction amount of the raw material flow rate, the water supply flow rate level under the current operating conditions needs to be used as a reference benchmark, so that the converted correction amount can reflect the raw material flow rate adjustment requirement corresponding to the unit concentration deviation under the current water supply conditions.

[0071] The controller adjusts the output based on the fluctuation range D of the mixing ratio deviation. c (k) Determine the stability of the ratio feedback S c (k). In this embodiment, the stability of the proportioning feedback is negatively correlated with the fluctuation range of the proportioning deviation; that is, the stability of the proportioning feedback decreases when the fluctuation range of the proportioning deviation increases. The controller will adjust the proportioning feedback stability... Defined as: ; where D c (k)≥0. When the fluctuation range of the proportion deviation D c When (k) = 0, S c (k) = 1, indicating that the proportioning deviation is completely stable; when the fluctuation range of the proportioning deviation increases, S c A decrease in (k) indicates more drastic fluctuations in the proportion deviation and a lower degree of stability in the proportion feedback. The controller determines the additional stability correction M based on the amplitude of the proportion deviation fluctuation and the average water supply flow rate corresponding to multiple consecutive sampling periods that form the proportion deviation sequence. c_stab (k). The controller will provide feedback on the instability of the proportioning 1-S. c (k) multiplied by the average water supply flow rate The stability correction is obtained as follows: The basic feedback correction and the additional stability correction are both non-negative values. The proportioning feedback correction only indicates the correction magnitude, and its positive or negative direction is determined by the aforementioned proportioning feedback correction direction. The controller superimposes the basic feedback correction and the additional stability correction to obtain the non-negative proportioning feedback correction M. c (k): The stability-added correction is not used to determine the direction of the original solution flow rate adjustment, but rather to compensate for the magnitude of the basic feedback correction based on the degree of change in the proportion deviation over multiple consecutive sampling periods. When the proportion deviation fluctuation is small, it indicates that the actual proportion state changes relatively smoothly, and correction is mainly based on the representative value of the proportion deviation. When the proportion deviation fluctuation increases, it indicates that the current solution preparation process is affected by water supply disturbances, execution response lags, or flow detection fluctuations, requiring an improvement in the feedback regulation's ability to follow dynamic changes. Therefore, the stability-added correction, calculated based on the average water supply flow rate, is used to supplement the basic feedback correction.

[0072] It should be noted that the stability-added correction is not used as an independent basis for adjusting the stock solution flow rate. Instead, it compensates for the feedback correction amplitude based on the determined direction of the ratio feedback correction. When the ratio deviation representative value is zero or close to zero, it indicates that the overall deviation of the actual ratio concentration over multiple consecutive sampling periods is small. At this time, no clear trend of increasing or decreasing stock solution flow rate is formed, and the controller does not output the target stock solution flow rate correction value in the corresponding direction according to the preset maintenance strategy. When the ratio deviation representative value is greater than zero or less than zero, it indicates that the actual ratio concentration has a clear deviation direction relative to the target ratio concentration. In this case, the controller adds the stability-added correction to the basic feedback correction in the corresponding direction to improve the compensation capability for dynamic disturbances while maintaining the consistency of the correction direction. The stability-added correction is not used to change the ratio feedback correction direction, but rather to increase the flow rate adjustment amplitude in the original correction direction when a drastic change in the ratio state is detected, thereby reducing the feedback adjustment lag caused by the increased rate of change in the ratio state. When the ratio deviation remains stable over multiple consecutive sampling periods, the representative value of the ratio deviation can accurately reflect the direction of deviation of the actual ratio concentration. At this time, the adjustment is mainly based on the basic feedback correction amount. When the fluctuation range of the ratio deviation increases, it indicates that there is a large dynamic disturbance in the current solution preparation process. Simply correcting based on the average deviation may not be able to reflect the changes in the current ratio state in a timely manner. Therefore, the stability additional correction amount is used to supplement the feedback correction range, so that the target original solution flow rate correction value can simultaneously consider long-term deviation and dynamic change factors.

[0073] The controller adjusts the proportioning feedback correction amount M according to the proportioning feedback correction direction. c (k) is converted to the target original liquid flow rate correction value ΔQ corresponding to the current sampling period. f (k). When the ratio feedback correction direction is the increasing direction, ΔQf (k)= M c (k); When the ratio feedback correction direction is the reduction direction, ΔQ f (k) = -M c (k); When the ratio feedback correction direction is the maintenance direction, ΔQ f (k) = 0. The controller will adjust the target original liquid flow rate by ΔQ. f (k) Stored in chronological order of sampling time. Although the target stock solution flow rate correction value is generated based on the data from the current sampling period, it only serves as feedback input during the generation of the target stock solution flow rate in the next sampling period and does not participate in the generation of the target stock solution flow rate in the current sampling period. During the generation of the target stock solution flow rate in the next sampling period, the controller reads the stored ΔQ. f (k) is the target stock solution flow rate correction value stored in the previous sampling period, which is used to perform ratio feedback correction on the basic target stock solution flow rate in the next sampling period.

[0074] Through the above methods, this embodiment characterizes the long-term deviation trend of the actual mixing concentration and the degree of dynamic change during the solution preparation process, respectively. This allows the target stock solution flow rate correction value to not only eliminate long-term mixing deviations but also adjust the feedback compensation amplitude according to the current dynamic state of the solution preparation process, thereby improving the concentration tracking capability during dynamic mixing. During the start-up phase of the actual solution preparation process, when the number of sampling periods stored in the actual mixing concentration sequence is less than N, the controller cannot form a mixing deviation sequence. At this time, the controller does not generate mixing feedback correction parameters and sets the target stock solution flow rate correction value ΔQ accordingly. f (k) is set to zero.

[0075] Furthermore, the total amount of mixed solution prepared is calculated based on the sum of the water supply flow rate and the original liquid flow rate corresponding to the current sampling cycle. When the amount of mixed solution prepared reaches the target total amount, or the actual running time reaches the target running time, the current mixing task is completed; otherwise, the next sampling cycle is entered, and steps S2 to S8 are repeated.

[0076] Specifically, in this embodiment, after each sampling cycle, the controller calculates the total amount of mixed solution prepared based on the water supply flow rate and the original liquid flow rate corresponding to the current sampling cycle. The current sampling cycle is denoted as the k-th sampling cycle, and the water supply flow rate corresponding to the current sampling cycle is denoted as Q. w (k), where Q is the original liquid flow rate corresponding to the current sampling period. r (k), where the preset sampling period is ΔT. Where Q w (k) and Q r (k) represents the periodic average flow rate within the corresponding sampling period, in units of volume / time. Within the sampling time interval ΔT corresponding to the current k-th sampling period, the actual output volume on the water supply side is Q.w (k)×ΔT, the actual output volume of the original liquid is Q. r The sum of (k)×ΔT represents the actual volume of the mixed liquid prepared in the current sampling period, ΔV(k). The controller adds the accumulated volume of the mixed liquid prepared in the current sampling period to the completed liquid preparation volume V. total Vtotal = ΣΔV(i), where i ranges from 1 to the current sampling period k. The completed liquid preparation volume V total This indicates the total cumulative volume of the mixed solution that has been actually output from the start of the solution preparation task to the end of the current sampling cycle.

[0077] After completing the above cumulative calculation in each sampling period, the controller determines whether the shutdown conditions are met. The shutdown conditions include the following two: Condition 1: Solution preparation volume V has been completed. total To achieve the user-defined target total volume V of solution set V total ≥V set .

[0078] Condition 2: Actual running time T run Achieve the user-defined target runtime T set That is, T run ≥T set .

[0079] If either of the above two conditions is met first, the controller will determine that the current solution preparation task is completed and execute a shutdown operation.

[0080] When the shutdown conditions are met, the controller stops the raw material side delivery actuator and closes the water supply valve to end the solution preparation process. After the shutdown operation is completed, the controller can optionally issue a solution preparation completion prompt signal, such as displaying solution preparation completion information on the touch screen or driving a buzzer to emit a prompt sound. When neither condition is met, the controller enters the next sampling cycle and repeats steps S2 to S8 to continue the solution preparation process.

[0081] Target total solution volume V set and target running time T set This refers to the parameters for the solution preparation task input by the user via the touchscreen. When the user only sets the target total solution volume without setting the target running time, the controller will only determine whether to stop based on condition one; when the user only sets the target running time without setting the target total solution volume, the controller will only determine whether to stop based on condition two; when the user sets both parameters simultaneously, the controller will use the first one achieved as the stop trigger condition. At the initial stage of the solution preparation process, the completed solution volume V... totalThe value is zero. As the sampling cycle progresses, the controller continuously accumulates the value at the end of each cycle until the shutdown condition is met. The completed liquid preparation volume is accumulated based on the actual detected water supply flow rate and raw liquid flow rate. It is used to reflect the actual total output mixed liquid volume and is independent of the ratio feedback correction process used to adjust the target raw liquid flow rate.

[0082] like Figure 2 As shown, based on the same inventive concept as the intelligent liquid dynamic proportioning method based on PID closed-loop control in the foregoing embodiments, this application provides an intelligent liquid dynamic proportioning system based on PID closed-loop control, the system comprising: The task configuration module 11 is used to obtain the target concentration ratio and solution preparation task parameters, wherein the target concentration ratio is set by the user, and the solution preparation task parameters include at least the target total solution volume and / or the target running time. Water supply detection module 12 is used to obtain the water supply flow rate corresponding to the current sampling period according to the preset sampling period and store it in the water supply flow rate sequence; The feedforward compensation module 13 is used to calculate the rate of change of water supply flow and the fluctuation range of water supply flow in the current sampling period according to the water supply flow sequence, generate the water supply correction value for the current sampling period according to the rate of change of water supply flow and the fluctuation range of water supply flow, perform feedforward compensation on the water supply flow corresponding to the current sampling period according to the water supply correction value to obtain the corrected water supply flow for the current sampling period, and generate the basic target original liquid flow for the current sampling period according to the corrected water supply flow and the target ratio concentration. The response correction module 14 is used to acquire the target stock solution flow rate and stock solution flow rate corresponding to multiple consecutive completed sampling periods stored in the memory, and generate the stock solution response correction value for the current sampling period based on the consistency of change and flow deviation between the target stock solution flow rate and the stock solution flow rate. The stock solution response correction value is used to characterize the historical following response of the stock solution flow rate to the target stock solution flow rate corresponding to the sampling period, and is used to correct the basic target stock solution flow rate for the current sampling period. The target generation module 15 is used to obtain the target stock solution flow correction value stored in the previous sampling period and the stock solution response correction value in the current sampling period, correct the basic target stock solution flow, and generate the target stock solution flow corresponding to the current sampling period. PID control module 16 is used to control the speed or output flow of the servo-driven gear pump by using the target raw liquid flow rate corresponding to the current sampling period as the target value of PID closed-loop regulation, so that the raw liquid flow rate tracks the target raw liquid flow rate, obtains the raw liquid flow rate corresponding to the current sampling period, and stores it in the raw liquid flow rate sequence. The feedback analysis module 17 is used to obtain the water supply flow rate and the raw liquid flow rate corresponding to the current sampling period based on the water supply flow rate sequence and the raw liquid flow rate sequence, calculate the actual ratio concentration of the current sampling period, store the actual ratio concentration of the current sampling period into the actual ratio concentration sequence; obtain the actual ratio concentration of multiple consecutive sampling periods including the current sampling period in the actual ratio concentration sequence, compare them with the target ratio concentration respectively to obtain the ratio deviation sequence, and generate the ratio feedback correction parameter based on the ratio deviation sequence, wherein the ratio feedback correction parameter is used to characterize the deviation amplitude of the actual ratio concentration relative to the target ratio concentration and the stability of the ratio deviation with the sampling period; The task execution module 18 is used to generate and store the target stock solution flow correction value corresponding to the current sampling period based on the ratio feedback correction parameters. The target stock solution flow correction value corresponding to the current sampling period is used to generate the target stock solution flow rate in the next sampling period. The module calculates the amount of mixed solution that has been prepared based on the sum of the water supply flow rate and the stock solution flow rate corresponding to the current sampling period. When the amount of mixed solution that has been prepared reaches the target total amount of mixed solution, or the actual running time reaches the target running time, the current mixing task is completed. Otherwise, the module enters the next sampling period and repeats the process from the water supply detection module to the task execution module.

[0083] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not 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

1. A smart liquid dynamic proportioning method based on PID closed-loop control, characterized in that, The method includes the following steps: S1. Obtain the target concentration ratio and solution preparation task parameters, wherein the target concentration ratio is set by the user, and the solution preparation task parameters include at least the target total solution volume and / or the target running time; S2. Obtain the water supply flow rate corresponding to the current sampling period according to the preset sampling period, and store it in the water supply flow rate sequence; S3. Calculate the water supply flow change rate and water supply flow fluctuation amplitude for the current sampling period based on the water supply flow sequence, generate the water supply correction value for the current sampling period based on the water supply flow change rate and water supply flow fluctuation amplitude, perform feedforward compensation on the water supply flow corresponding to the current sampling period based on the water supply correction value to obtain the corrected water supply flow for the current sampling period, and generate the basic target stock solution flow for the current sampling period based on the corrected water supply flow and the target ratio concentration. S4. Obtain the target stock solution flow rate and stock solution flow rate corresponding to multiple consecutive completed sampling periods. Based on the consistency of change and flow deviation between the target stock solution flow rate and the stock solution flow rate, generate the stock solution response correction value for the current sampling period. The stock solution response correction value is used to characterize the historical following response of the stock solution flow rate to the target stock solution flow rate corresponding to the sampling period, and is used to correct the basic target stock solution flow rate for the current sampling period. S5. Obtain the target stock solution flow correction value stored in the previous sampling period and the stock solution response correction value in the current sampling period, correct the basic target stock solution flow rate, and generate the target stock solution flow rate corresponding to the current sampling period. S6. Using the target stock liquid flow rate corresponding to the current sampling period as the target value of PID closed-loop regulation, control the speed or output flow rate of the servo-driven gear pump so that the stock liquid flow rate tracks the target stock liquid flow rate, obtain the stock liquid flow rate corresponding to the current sampling period, and store it in the stock liquid flow rate sequence. S7. Based on the water supply flow rate sequence and the raw liquid flow rate sequence, obtain the water supply flow rate and raw liquid flow rate corresponding to the current sampling period, calculate the actual ratio concentration of the current sampling period, and store the actual ratio concentration of the current sampling period into the actual ratio concentration sequence; obtain the actual ratio concentration of multiple consecutive sampling periods including the current sampling period in the actual ratio concentration sequence, and compare them with the target ratio concentration respectively to obtain the ratio deviation sequence; generate the ratio feedback correction parameter based on the ratio deviation sequence, wherein the ratio feedback correction parameter is used to characterize the deviation amplitude of the actual ratio concentration relative to the target ratio concentration and the stability of the ratio deviation as the sampling period changes; S8. Generate and store the target stock solution flow correction value corresponding to the current sampling period based on the ratio feedback correction parameter. The target stock solution flow correction value corresponding to the current sampling period is used to generate the target stock solution flow rate in the next sampling period. Calculate the amount of mixed solution prepared based on the sum of the water supply flow rate and the stock solution flow rate corresponding to the current sampling period. When the amount of mixed solution prepared reaches the target total amount, or the actual running time reaches the target running time, the current mixing task is completed; otherwise, proceed to the next sampling period and repeat steps S2 to S8.

2. The intelligent liquid dynamic proportioning method based on PID closed-loop control according to claim 1, characterized in that, Based on the water supply correction value, feedforward compensation is performed on the water supply flow rate corresponding to the current sampling period to obtain the corrected water supply flow rate for the current sampling period, including: Obtain the water supply flow rate corresponding to the current sampling period and the water supply flow rate corresponding to multiple consecutive historical sampling periods stored in the water supply flow rate sequence, wherein the water supply flow rate represents the periodic average flow rate value calculated from the water supply flow rate sample values ​​within the corresponding sampling period. Based on the difference between the water supply flow rate corresponding to the current sampling period and the water supply flow rate corresponding to the previous sampling period, and the preset sampling period, the water supply flow rate change rate for the current sampling period is calculated. The water supply change trend corresponding to the current sampling period is determined based on the sign of the water supply flow rate change rate. Specifically, a water supply flow rate change rate greater than zero corresponds to an upward trend, a water supply flow rate change rate less than zero corresponds to a downward trend, and a water supply flow rate change rate equal to zero corresponds to a stable trend. The fluctuation range of water supply flow in the current sampling period is calculated based on the current sampling period and the difference between the maximum and minimum values ​​of water supply flow in the previous multiple consecutive sampling periods. The water supply correction value for the current sampling period is generated based on the water supply change trend and the fluctuation range of the water supply flow. Based on the water supply correction value, feedforward compensation is performed on the water supply flow corresponding to the current sampling period to obtain the corrected water supply flow corresponding to the current sampling period; The corrected water supply flow rate is used to generate the base target stock solution flow rate for the current sampling period. The base target stock solution flow rate is then corrected by the stock solution response and the ratio feedback to generate the target stock solution flow rate for the current sampling period.

3. The intelligent liquid dynamic proportioning method based on PID closed-loop control according to claim 2, characterized in that, Based on the water supply correction value, feedforward compensation is performed on the water supply flow rate corresponding to the current sampling period to obtain the corrected water supply flow rate corresponding to the current sampling period, including: The rate of change of water supply flow rate in the current sampling period is denoted as R. w (k) represents the fluctuation range of the water supply flow rate during the current sampling period, denoted as A. w (k), where the preset sampling period is denoted as △T; Obtain the water supply change trend corresponding to the current sampling period, and determine the water supply correction direction corresponding to the current sampling period based on the water supply change trend, wherein: When the water supply change trend is upward, the water supply correction direction is determined to be an increasing direction; When the water supply change trend is downward, the water supply correction direction is determined to be a reduction direction; When the water supply change trend is a stable trend, the water supply correction direction is determined to be the maintenance direction; According to the preset weights, |R w (k)|×△T and the fluctuation range of the water supply flow rate A w (k) is weighted to obtain the water supply compensation amplitude M(k) corresponding to the current sampling period, where M(k)≥0. The preset weight is used to characterize the influence of water supply change trend and water supply flow fluctuation amplitude on water supply correction amount. Based on the water supply correction direction and the water supply compensation amplitude M(k), the water supply correction value ΔQ corresponding to the current sampling period is generated. w (k), where: When the water supply correction direction is increasing, ΔQ w (k)=M(k); When the water supply correction direction is a decreasing direction, ΔQ w (k)=-M(k); When the water supply correction direction is the maintenance direction, ΔQ w (k)=0; According to the water supply correction value ΔQ w (k) The water supply flow rate Q corresponding to the current sampling period w (k) Perform feedforward compensation to obtain the corrected water supply flow rate Q. w ′(k), where: Q w ′(k)=Q w (k)+ΔQ w (k); The corrected water supply flow rate Q w ′(k) is used to generate the base target original liquid flow rate for the current sampling period.

4. The intelligent liquid dynamic proportioning method based on PID closed-loop control according to claim 3, characterized in that, The base target stock solution flow rate for the current sampling period is generated based on the corrected water supply flow rate and the target concentration ratio, including: The target concentration ratio is denoted as C. t The C t This indicates the target volume ratio of the stock solution in the mixture, as set by the user. Calculate the target flow ratio coefficient K c The formula is as follows: K c =C t / (1-C t ); Based on the corrected water supply flow rate Q corresponding to the current sampling period w ′(k) and the target flow rate proportionality coefficient K c Calculate the baseline target original liquid flow rate Q for the current sampling period. o 0(k), the formula is as follows: Q o 0(k)=K c ×Q w ′(k); The basic target stock solution flow rate is the initial target stock solution flow rate calculated based on the corrected water supply flow rate and target ratio concentration corresponding to the current sampling period, and is used for stock solution response correction and ratio feedback correction.

5. The intelligent liquid dynamic proportioning method based on PID closed-loop control according to claim 1, characterized in that, Based on the consistency between the target stock solution flow rate and the stock solution flow rate, as well as the flow rate deviation, a stock solution response correction value for the current sampling period is generated, including: Obtain the target stock solution flow rate and the corresponding stock solution flow rate for a series of consecutive completed sampling cycles stored before the current sampling cycle, wherein the number of the series of consecutive completed sampling cycles is not less than two; Based on the difference between the target stock liquid flow rate and the corresponding stock liquid flow rate for each completed sampling cycle, a stock liquid flow rate deviation sequence is generated, and the average deviation is calculated based on the stock liquid flow rate deviation sequence. Based on the magnitude relationship between the target stock solution flow rates corresponding to adjacent completed sampling cycles, the direction of change of the target stock solution flow rate corresponding to each adjacent sampling cycle is determined. Based on the magnitude relationship between the stock solution flow rates corresponding to adjacent completed sampling cycles, the direction of change of the stock solution flow rate corresponding to each adjacent sampling cycle is determined. The number of times the direction of change of the target stock solution flow rate is consistent with the direction of change of the stock solution flow rate is counted to obtain the number of times the direction of change is consistent. Based on the number of times the direction of change is consistent, the degree of inconsistency in the response is determined. The direction of change of the target stock solution flow rate and the direction of change of the stock solution flow rate both include the direction of increase, the direction of decrease, and the direction of no change. The direction of original solution response correction corresponding to the current sampling period is determined based on the average deviation, wherein: When the average deviation is greater than zero, the direction of the original solution response correction is determined to be the increasing direction; When the average deviation is less than zero, the direction of the original solution response correction is determined to be the reduction direction; When the average deviation is equal to zero, the original solution response correction direction is determined to be the maintenance direction; The basic response correction amount is determined based on the absolute value of the average deviation. The additional response correction amount is determined based on the degree of response inconsistency and the average target original liquid flow rate corresponding to the completed sampling period. The basic response correction amount and the additional response correction amount are superimposed to obtain the original liquid response correction amount corresponding to the current sampling period. The sign corresponding to the original liquid response correction direction and the original liquid response correction amount are combined to generate the original liquid response correction value corresponding to the current sampling period. The original liquid response correction value is used to characterize the flow deviation and change following consistency of the original liquid flow rate relative to the target original liquid flow rate within multiple consecutive completed sampling periods, so as to reflect the historical following response of the original liquid flow rate to the target original liquid flow rate, and is used to correct the basic target original liquid flow rate of the current sampling period.

6. The intelligent liquid dynamic proportioning method based on PID closed-loop control according to claim 1, characterized in that, Obtain the target stock solution flow rate correction value stored in the previous sampling period and the stock solution response correction value in the current sampling period, correct the basic target stock solution flow rate, and generate the target stock solution flow rate corresponding to the current sampling period, including: Obtain the target original liquid flow correction value ΔQ stored in the previous sampling period. f (k-1), the base target original liquid flow rate Q in the current sampling period. o 0(k), the original liquid response correction value ΔQ for the current sampling period. r (k); Based on the aforementioned basic target original liquid flow rate Q o 0(k), the original solution response correction value ΔQ r (k) and the target original liquid flow rate correction value ΔQ f (k-1), generate the target original liquid flow rate Q for the current sampling period. o t(k), the formula is as follows: Q o t(k)= Q o 0(k)+ΔQ r (k)+ΔQ f (k-1); Wherein, the target original liquid flow rate Q o t(k) is used as the target value of the PID closed-loop regulation in the current sampling period to control the servo-driven gear pump to perform raw liquid flow regulation.

7. The intelligent liquid dynamic proportioning method based on PID closed-loop control according to claim 1, characterized in that, Calculate the actual concentration ratio for the current sampling period, including: Obtain the water supply flow rate Q corresponding to the current sampling period. w (k), and the original liquid flow rate Q corresponding to the current sampling period. r (k), where the original liquid flow rate represents the periodic average flow rate value calculated from the original liquid flow rate sampling values ​​within the corresponding sampling period, and the actual proportion concentration C of the current sampling period is calculated. a (k), the formula is as follows: C a (k)=Q r (k) / (Q w (k)+Q r (k)); Wherein, the actual concentration ratio C a (k) represents the actual ratio result formed by the water supply flow rate and the original liquid flow rate corresponding to the current sampling period, which is used to characterize the actual ratio state of the current sampling period; The actual concentration ratio C a (k) Store the actual ratio concentration sequence in the order of sampling time. The actual ratio concentration sequence is used to obtain the actual ratio concentration corresponding to multiple consecutive sampling periods in order to generate ratio feedback correction parameters.

8. The intelligent liquid dynamic proportioning method based on PID closed-loop control according to claim 7, characterized in that, Generate ratio feedback correction parameters based on the ratio deviation sequence, including: Obtain the actual ratio concentration of the actual ratio concentration in the actual ratio concentration sequence, including the current sampling period, for a continuous multiple sampling periods, wherein the number of the continuous multiple sampling periods is not less than two; The actual concentration ratio corresponding to each sampling period is compared with the target concentration ratio, and the concentration ratio ratio is obtained by subtracting the actual concentration ratio from the target concentration ratio. A concentration ratio ratio ratio deviation sequence is generated according to the sampling time sequence. The average value of the ratio deviation is obtained by averaging the ratio deviations in the ratio deviation sequence. The fluctuation range of the proportion deviation is obtained by the difference between the maximum and minimum proportion deviations in the proportion deviation sequence. The representative value of the ratio deviation and the fluctuation range of the ratio deviation are used as the ratio feedback correction parameters; The ratio deviation representative value is used to characterize the direction and magnitude of the deviation of the actual ratio concentration from the target ratio concentration within multiple consecutive sampling periods, and the ratio deviation fluctuation amplitude is used to characterize the degree of fluctuation of the ratio deviation within multiple consecutive sampling periods.

9. The intelligent liquid dynamic proportioning method based on PID closed-loop control according to claim 8, characterized in that, Generate and store the target stock solution flow rate correction value corresponding to the current sampling period based on the ratio feedback correction parameters, including: Obtain the representative value of the ratio deviation and the fluctuation range of the ratio deviation from the ratio feedback correction parameters; The direction of ratio feedback correction is determined based on the representative value of the ratio deviation, wherein: When the representative value of the ratio deviation is greater than zero, the ratio feedback correction direction is determined to be the increasing direction; When the representative value of the ratio deviation is less than zero, the ratio feedback correction direction is determined to be the reduction direction; When the representative value of the ratio deviation is equal to zero, the ratio feedback correction direction is determined to be the maintenance direction; The basic feedback correction amount is determined based on the absolute value of the representative value of the ratio deviation. The stability additional correction amount is determined based on the fluctuation range of the ratio deviation and the average water supply flow rate corresponding to multiple consecutive sampling periods that form the ratio deviation sequence. The basic feedback correction amount and the stability additional correction amount are superimposed to obtain a non-negative ratio feedback correction amount. The sign corresponding to the ratio feedback correction direction and the ratio feedback correction amount are combined to generate the target original liquid flow rate correction value corresponding to the current sampling period, wherein: When the ratio feedback correction direction is increasing, the target original liquid flow rate correction value is positive; When the direction of the ratio feedback correction is a decrease, the target original liquid flow rate correction value is negative; When the ratio feedback correction direction is the maintenance direction, the target original liquid flow rate correction value is zero. The target stock solution flow rate correction value is stored in the order of sampling time for use when generating the target stock solution flow rate in the next sampling cycle.

10. A smart liquid dynamic proportioning system based on PID closed-loop control, characterized in that, The system includes: The task configuration module is used to obtain the target concentration ratio and solution preparation task parameters, wherein the target concentration ratio is set by the user, and the solution preparation task parameters include at least the target total solution volume and / or the target running time; The water supply detection module is used to obtain the water supply flow rate corresponding to the current sampling period according to the preset sampling period and store it into the water supply flow rate sequence. The feedforward compensation module is used to calculate the rate of change and fluctuation of water supply flow in the current sampling period based on the water supply flow sequence, generate the water supply correction value for the current sampling period based on the rate of change and fluctuation of water supply flow, perform feedforward compensation on the water supply flow corresponding to the current sampling period based on the water supply correction value to obtain the corrected water supply flow for the current sampling period, and generate the basic target stock solution flow for the current sampling period based on the corrected water supply flow and the target ratio concentration. The response correction module is used to acquire the target stock solution flow rate and stock solution flow rate corresponding to multiple consecutive completed sampling periods, and generate the stock solution response correction value for the current sampling period based on the consistency of change and flow deviation between the target stock solution flow rate and the stock solution flow rate. The stock solution response correction value is used to characterize the historical following response of the stock solution flow rate to the target stock solution flow rate corresponding to the sampling period, and is used to correct the base target stock solution flow rate for the current sampling period. The target generation module is used to obtain the target stock solution flow correction value stored in the previous sampling period and the stock solution response correction value in the current sampling period, correct the basic target stock solution flow rate, and generate the target stock solution flow rate corresponding to the current sampling period. The PID control module is used to control the speed or output flow of the servo-driven gear pump by using the target raw liquid flow rate corresponding to the current sampling period as the target value of the PID closed-loop regulation, so that the raw liquid flow rate tracks the target raw liquid flow rate, obtains the raw liquid flow rate corresponding to the current sampling period, and stores it in the raw liquid flow rate sequence. The feedback analysis module is used to obtain the water supply flow rate and raw liquid flow rate corresponding to the current sampling period based on the water supply flow rate sequence and the raw liquid flow rate sequence, calculate the actual ratio concentration of the current sampling period, and store the actual ratio concentration of the current sampling period into the actual ratio concentration sequence; obtain the actual ratio concentration of multiple consecutive sampling periods including the current sampling period in the actual ratio concentration sequence, and compare them with the target ratio concentration respectively to obtain the ratio deviation sequence; generate ratio feedback correction parameters based on the ratio deviation sequence, wherein the ratio feedback correction parameters are used to characterize the deviation amplitude of the actual ratio concentration relative to the target ratio concentration and the stability of the ratio deviation with the sampling period; The task execution module is used to generate and store the target stock solution flow rate correction value corresponding to the current sampling period based on the ratio feedback correction parameters. The target stock solution flow rate correction value corresponding to the current sampling period is used to generate the target stock solution flow rate in the next sampling period. The module calculates the amount of mixed solution prepared based on the sum of the water supply flow rate and the stock solution flow rate corresponding to the current sampling period. When the amount of mixed solution prepared reaches the target total amount, or the actual running time reaches the target running time, the current mixing task is completed. Otherwise, the module proceeds to the next sampling period and repeats the process from the water supply detection module to the task execution module.

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