Acid-base reagent constant-current supply system and testing method

Abstract

The invention discloses an acid-base reagent constant-current supply system and a test method, and relates to the technical field of acid-base reagent constant-current test.The method comprises the steps that before titration is started, initialization setting is conducted on a multi-channel pumping system, and a pressure sensor and a flow meter are started to collect real-time supply state data of all channels; based on the collected pressure measurement value and flow data, a dynamic PI D feedback control algorithm is adopted to adjust pump output so as to maintain constant flow speed output of the acid-base reagent under different load conditions; on the basis of stable supply of an acid-base reagent, continuously collecting a pH value change signal in the titration process by using a pH sensor, identifying a first derivative and a second derivative of a titration reaction based on a time sequence analysis method, and judging a titration inflection point moment when the second derivative exceeds a preset threshold value; and based on the identified first-order derivative and the identified second-order derivative, calling a fuzzy rule base to judge the grade of the titration rate which needs to be adopted at present, and realizing nonlinear self-adaptive adjustment of the titration rate.

Description

Technical Field

[0001] The present invention relates to the technical field of constant current testing of acid and alkali reagents, in particular to a constant current supply system and testing method of acid and alkali reagents. Background Art

[0002] Acid and base reagent constant-current testing technology involves precisely controlling the supply rate of acid or base reagents during chemical analysis to ensure consistent and stable reaction conditions. This technology is widely used in titration analysis, microfluidics systems, automated chemical analysis instruments, and online monitoring. Therefore, utilizing advanced technologies to improve the intelligence and safety of acid and base reagent constant-current testing has become a pressing issue.

[0003] In the field of constant-current testing of acid and base reagents, in actual operation, the existing technology is often unstable in the reagent supply flow rate due to factors such as load fluctuations and viscosity changes, resulting in deviations in experimental results. In addition, the traditional pH jump method has a delayed response when identifying the titration endpoint, which can easily cause excessive titration or misjudgment of the endpoint, affecting the experimental accuracy. At the same time, the traditional titration process uses a fixed titration rate and cannot be dynamically adjusted according to the reaction progress, resulting in low test efficiency or excessive consumption of reagents. Summary of the Invention

[0004] In view of the above existing problems, the present invention is proposed.

[0005] Therefore, the present invention provides a constant-current testing method for acid and base reagents to solve the problem of the existing technology in actual operation. Due to factors such as load fluctuations and viscosity changes, the reagent supply flow rate is often unstable, resulting in deviations in experimental results. In addition, the traditional pH jump method has a delayed response when identifying the titration end point, which can easily cause excessive titration or misjudgment of the end point, affecting the experimental accuracy. At the same time, the traditional titration process adopts a fixed titration rate, which cannot be dynamically adjusted according to the reaction progress, resulting in low test efficiency or excessive consumption of reagents.

[0006] In order to solve the above technical problems, the present invention provides the following technical solutions:

[0007] In a first aspect, the present invention provides a constant current testing method for acid-base reagents, comprising:

[0008] Before starting the titration, the multi-channel pumping system is initialized and the pressure sensor and flow meter are started to collect the real-time supply status data of each channel;

[0009] Based on the collected pressure measurement values ​​and flow data, a dynamic PID feedback control algorithm is used to adjust the pump output to maintain a constant flow rate output of acid and base reagents under different load conditions;

[0010] On the basis of stable supply of acid and base reagents, a pH sensor is used to continuously collect pH value change signals during the titration process, and the first and second derivatives of the titration reaction are identified based on the time series analysis method. When the second derivative exceeds the preset threshold, it is determined as the titration inflection point;

[0011] Based on the identified first-order derivative and second-order derivative, the fuzzy rule library is called to determine the current titration rate level to be adopted, thereby realizing nonlinear adaptive adjustment of the titration rate;

[0012] Based on the titration inflection point and the current titration rate, a delay compensation factor is introduced to correct the endpoint time to obtain the actual titration end time;

[0013] Record experimental data during the process, including final reagent consumption volume, titration endpoint time and corresponding pH value, and generate a titration process report.

[0014] As a preferred embodiment of the constant current test method for acid and base reagents of the present invention, the parameter setting in the dynamic PID feedback control algorithm specifically includes the following steps:

[0015] The historical calibration curve is used to convert the flow rate target Q0 set in the current experiment to obtain the corresponding reference pressure value P ref ;

[0016] According to the collected pressure measurement value P meas and flow data, calculate error signal;

[0017] Use the scaling factor K p , integral coefficient K i and differential coefficient K d Performing weighted compensation processing on the error signal;

[0018] The target output flow rate Q of the current channel is calculated by the following expression target :

[0019]

[0020] Among them, Q0 is the initial target flow rate set by the user, P ref is the standard reference pressure obtained by looking up the table or interpolating Q0, P meas is the pressure value collected in real time by the pressure sensor, K p , K i , K d The proportional, integral, and differential coefficients of the PID controller are pre-calibrated according to the system response characteristics;

[0021] According to the target output flow rate Q targetAdjust the pump output voltage or pulse frequency to make the actual supply flow rate approach the set value, so as to achieve constant flow rate output under different load conditions.

[0022] As a preferred embodiment of the constant current test method for acid-base reagents of the present invention, the method for identifying the titration inflection point based on time series analysis specifically comprises the following steps:

[0023] On the basis of stable supply of acid and alkali reagents, the pH sensor is used to continuously collect the pH change signal of the solution during the titration process at a fixed sampling frequency fsfs;

[0024] The collected pH sequence is divided into multiple time windows, each window contains N sampling points;

[0025] The sliding window method was used to perform a linear fit on the pH values ​​within each window, and the first-order derivative ΔpH within the window was calculated;

[0026] The first-order derivative ΔpH is defined as the rate of change of pH value within the window, that is:

[0027]

[0028] Among them, pH i+1 is the pH value of the i-th and i+1-th sampling points, t i , t i+1 is the corresponding sampling time;

[0029] Perform sliding window analysis on the first-order derivative sequence again to obtain the second-order derivative Δ 2 pH;

[0030] The second-order derivative Δ 2 pH represents the changing trend of the first-order derivative and is defined as:

[0031]

[0032] Where ΔpH j+1 is the ΔpH of two adjacent windows, t j , t j+1 is the time center point of the corresponding window;

[0033] When Δ 2 When the absolute value of pH exceeds the preset threshold θ, the current moment is marked as the inflection point of the titration reaction t detect .

[0034] As a preferred embodiment of the constant current test method for acid-base reagents of the present invention, the method for identifying the titration inflection point based on time series analysis specifically comprises the following steps:

[0035] On the basis of stable supply of acid and alkali reagents, the pH sensor is used to continuously collect the pH change signal of the solution during the titration process at a fixed sampling frequency fsfs;

[0036] The collected pH sequence is divided into multiple time windows, each window contains N sampling points;

[0037] The sliding window method was used to perform a linear fit on the pH values ​​within each window, and the first-order derivative ΔpH within the window was calculated;

[0038] The first-order derivative ΔpH is defined as the rate of change of pH value within the window, that is:

[0039]

[0040] Among them, pH i+1 is the pH value of the i-th and i+1-th sampling points, t i , t i+1 is the corresponding sampling time;

[0041] Perform sliding window analysis on the first-order derivative sequence again to obtain the second-order derivative Δ 2 pH;

[0042] The second-order derivative Δ 2 pH represents the changing trend of the first-order derivative and is defined as:

[0043]

[0044] Where ΔpH j+1 is the ΔpH of two adjacent windows, t j , t j+1 is the time center point of the corresponding window;

[0045] When Δ 2 When the absolute value of pH exceeds the preset threshold θ, the current moment is marked as the inflection point of the titration reaction t detect .

[0046] As a preferred embodiment of the constant current test method for acid and base reagents of the present invention, the method of introducing a delay compensation factor to correct the endpoint time specifically comprises the following steps:

[0047] Based on the titration inflection point t detect , and the average titration rate v corresponding to the current titration rate level;

[0048] Introducing delay compensation factor D c , the delay compensation factor is pre-calibrated according to the system response time and sensor hysteresis characteristics;

[0049] The actual titration end time t is calculated using the following formula:stop :

[0050] t stop =t detect -D c ΔpH(t);

[0051] Among them, t detect is the titration inflection point, D c is the empirical correction coefficient, ΔpH(t) is the pH difference between the current moment and the previous moment;

[0052] The corrected termination time t stop End the titration operation early to avoid over-titration caused by delayed sensor response;

[0053] Finally, the titration endpoint position and reagent consumption volume are obtained.

[0054] As a preferred embodiment of the constant current test method for acid and base reagents of the present invention, the method for recording experimental data and generating a titration process report specifically comprises the following steps:

[0055] Record all experimental data, including the initial set flow rate, real-time pressure values ​​of each channel, actual supply flow rate, pH value change curve, titration inflection point, actual titration end time, total reagent consumption volume and final pH value;

[0056] Integrate the above data into a complete titration process report in a structured manner;

[0057] The report includes titration curve, key time node annotation, reagent usage statistics and system operation status summary;

[0058] It also supports exporting to highly readable data file formats for subsequent analysis and archiving.

[0059] As a preferred embodiment of the constant current test method for acid and base reagents of the present invention, the method for automatically evaluating the repeatability and stability of the test specifically comprises the following steps:

[0060] While generating the titration process report, the repeatability and stability indicators of this test are automatically evaluated;

[0061] The evaluation is based on comparison of historical test data under the same conditions, including comparison of titration endpoint deviation, reagent consumption fluctuation range, and pH response slope consistency between the current test and historical data;

[0062] If any of the above deviations exceed the preset tolerance, it will be marked as an abnormal test;

[0063] and prompt the user to check system status, recalibrate sensors, or change reagent batches;

[0064] This evaluation mechanism continuously monitors test quality and ensures the reliability and repeatability of test results.

[0065] In a second aspect, the present invention provides a constant flow supply system for acid and alkali reagents, comprising:

[0066] Initialization setting module, dynamic control module, inflection point recognition module, rate adjustment module, endpoint correction module and data processing module;

[0067] The initialization setting module is used to set parameters of the multi-channel pumping system before starting titration, and to start the pressure sensor and flow meter to collect real-time supply status data of each channel;

[0068] The dynamic control module is used to adjust the pump output based on the collected pressure measurement value and flow data using a dynamic PID feedback control algorithm to maintain a constant flow rate output of the acid and base reagents under different load conditions;

[0069] The inflection point identification module is used to continuously collect pH value change signals during the titration process using a pH sensor on the basis of a stable supply of acid and base reagents, and identify the first-order derivative and second-order derivative of the titration reaction based on a time series analysis method. When the second-order derivative exceeds a preset threshold, it is determined to be the titration inflection point moment;

[0070] The rate adjustment module is used to call the fuzzy rule library to determine the titration rate level to be currently adopted based on the identified first-order derivative and second-order derivative, thereby realizing nonlinear adaptive adjustment of the titration rate;

[0071] The endpoint correction module is used to introduce a delay compensation factor to correct the endpoint time based on the titration inflection point moment determined by the inflection point recognition module and the current titration rate output by the rate adjustment module to obtain the actual titration termination time;

[0072] The data processing module is used to record the experimental data generated during the entire test process, including the final reagent consumption volume, titration endpoint time and corresponding pH value, and generate a complete titration process report, while evaluating the repeatability and stability of the test.

[0073] The beneficial effects of the present invention are: by introducing a dynamic PID feedback control algorithm, high stability and consistency of multi-channel reagent supply are achieved; combined with the titration inflection point recognition technology based on time series analysis, the sensitivity and accuracy of titration endpoint judgment are significantly improved; at the same time, a fuzzy logic control strategy is adopted to achieve nonlinear adaptive adjustment of the titration rate, taking into account both test efficiency and accuracy; and by introducing a delay compensation mechanism, the error caused by sensor response lag is effectively corrected, further improving the repeatability and reliability of the test results; in addition, the system has complete data recording and quality assessment functions, supports full process traceability and intelligent management, and is suitable for a variety of application scenarios such as microfluidics, automatic titration and online monitoring. BRIEF DESCRIPTION OF THE DRAWINGS

[0074] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0075] Figure 1 Flow chart of the constant current test method for acid and base reagents in the embodiment.

[0076] Figure 2 Schematic diagram of the constant flow supply system for acid and alkali reagents in the embodiment. DETAILED DESCRIPTION

[0077] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the specific embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0078] In the following description, many specific details are set forth to facilitate a full understanding of the present invention. However, the present invention may also be implemented in other ways different from those described herein. Those skilled in the art may make similar generalizations without violating the connotation of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0079] Secondly, the term "one embodiment" or "embodiment" herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. The phrase "in one embodiment" appearing in various places throughout this specification does not necessarily refer to the same embodiment, nor does it refer to a separate or selective embodiment that is mutually exclusive of other embodiments.

[0080] Reference Figure 1 and Figure 2 This embodiment provides a constant current testing method for acid-base reagents, comprising the following steps:

[0081] S1. Before starting titration, initialize the multi-channel pumping system and start the pressure sensor and flow meter to collect real-time supply status data of each channel;

[0082] Furthermore, before starting the titration, the system initialization steps are performed, including setting the initial flow rate according to the experimental requirements, obtaining the corresponding reference pressure value through the historical calibration curve lookup table, and simultaneously starting the pressure sensors and flow meters of each channel in the multi-channel pumping system to collect the pressure measurement value and actual flow rate information of the current reagent delivery process in real time to support the error calculation and output adjustment of the subsequent PID feedback control algorithm;

[0083] It should be noted that the initialization setting process provides stable initial conditions and a repeatable operating basis for the entire test process. The real-time supply status data collected by the pressure sensor and flow meter can accurately reflect the current system operation status and provide key input information for the subsequent dynamic PID control algorithm, thereby ensuring that acid and alkali reagents can achieve constant flow rate output under different experimental conditions.

[0084] S2. Based on the collected pressure measurement values ​​and flow data, a dynamic PID feedback control algorithm is used to adjust the pump output to maintain a constant flow rate output of acid and base reagents under different load conditions;

[0085] Furthermore, the historical calibration curve is used to convert the flow rate target Q0 set in the current experiment to obtain the corresponding reference pressure value P ref ;

[0086] According to the collected pressure measurement value P meas and flow data, calculate error signal;

[0087] Use the scaling factor K p , integral coefficient K i and differential coefficient K d Performing weighted compensation processing on the error signal;

[0088] The target output flow rate Q of the current channel is calculated by the following expression target :

[0089]

[0090] Among them, Q0 is the initial target flow rate set by the user, P ref is the standard reference pressure obtained by looking up the table or interpolating Q0, P meas is the pressure value collected in real time by the pressure sensor, K p , K i , K d The proportional, integral, and differential coefficients of the PID controller are pre-calibrated according to the system response characteristics;

[0091] According to the target output flow rate Q target Adjust the pump output voltage or pulse frequency to make the actual supply flow rate close to the set value, which is used to achieve constant flow rate output under different load conditions;

[0092] It should be noted that the dynamic PID feedback control algorithm relies on the reference pressure value obtained in the initialization phase and the real-time pressure measurement value. It combines the proportional coefficient, integral coefficient and differential coefficient to construct an error compensation model, so that the pump output can be automatically adjusted according to the load change, thereby effectively suppressing flow rate fluctuations and improving the robustness and adaptability of the system. It is suitable for reagent supply control in complex multi-channel environments.

[0093] S3. On the basis of a stable supply of acid and base reagents, a pH sensor is used to continuously collect pH value change signals during the titration process, and the first and second derivatives of the titration reaction are identified based on a time series analysis method. When the second derivative exceeds a preset threshold, it is determined to be the titration inflection point;

[0094] Furthermore, on the basis of stable supply of acid and base reagents, a pH sensor is used to continuously collect the pH change signal of the solution during the titration process at a fixed sampling frequency fsfs;

[0095] The collected pH sequence is divided into multiple time windows, each window contains N sampling points;

[0096] The sliding window method was used to perform a linear fit on the pH values ​​within each window, and the first-order derivative ΔpH within the window was calculated;

[0097] The first-order derivative ΔpH is defined as the rate of change of pH within the window, that is:

[0098]

[0099] Among them, pH i+1 is the pH value of the i-th and i+1-th sampling points, t i , t i+1 is the corresponding sampling time;

[0100] Perform sliding window analysis on the first-order derivative sequence again to obtain the second-order derivative Δ 2 pH;

[0101] Second-order derivative Δ 2 pH represents the changing trend of the first-order derivative and is defined as:

[0102]

[0103] Where ΔpH j+1 is the ΔpH of two adjacent windows, t j , t j+1is the time center point of the corresponding window;

[0104] When Δ 2 When the absolute value of pH exceeds the preset threshold θ, the current moment is marked as the inflection point of the titration reaction t detect ;

[0105] It should be noted that the titration inflection point identification method based on time series analysis uses the data continuously collected by the pH sensor to construct the first-order derivative and the second-order derivative, which can capture the key turning points of the titration reaction earlier and more sensitively. Compared with the traditional pH jump method, it has higher response speed and judgment accuracy. At the same time, the sliding window processing method enhances the anti-interference ability to noise interference and improves the stability and credibility of the identification results.

[0106] S4. Based on the identified first-order derivative and second-order derivative, the fuzzy rule library is called to determine the titration rate level to be currently adopted, thereby realizing nonlinear adaptive adjustment of the titration rate;

[0107] Furthermore, based on the first-order derivative ΔpH and the second-order derivative Δ 2 pH, which are normalized to values ​​within the interval [0,1] and used as two input variables of the fuzzy controller;

[0108] Calling a preset fuzzy rule base, which contains multiple fuzzy sets and corresponding output titration rate levels;

[0109] When ΔpH is small and Δ 2 When the pH is close to zero, it is judged to be close to the end point area and a low-speed titration instruction is output;

[0110] When ΔpH is large and Δ 2 If the pH is small, it is judged as a stable reaction area and a high-speed titration instruction is output;

[0111] After fuzzy reasoning, the titration rate level v that should be adopted currently is output;

[0112] The output titration rate is used to control the pump drive module to achieve nonlinear adaptive adjustment of the titration rate;

[0113] The titration process is optimized to be fast at the beginning and slow at the end, improving the overall test efficiency and accuracy;

[0114] It should be noted that the method of calling the fuzzy rule library to adjust the titration rate realizes intelligent decision-making of the titration rate level by normalizing the first-order derivative and the second-order derivative as the input variables of the fuzzy controller and combining it with preset fuzzy inference rules. This nonlinear adaptive adjustment mechanism can significantly shorten the test time while ensuring the titration accuracy and improve the overall test efficiency. It is particularly suitable for titration scenarios of samples with different concentrations and different reaction kinetic characteristics.

[0115] S5. Based on the titration inflection point and the current titration rate, a delay compensation factor is introduced to correct the endpoint time to obtain the actual titration termination time;

[0116] Furthermore, based on the titration inflection point t detect , and the average titration rate v corresponding to the current titration rate level;

[0117] Introducing delay compensation factor D c ,The delay compensation factor is pre-calibrated according to the system response time and sensor hysteresis characteristics;

[0118] The actual titration end time t is calculated using the following formula: stop :

[0119] t stop =t detect -D c ΔpH(t);

[0120] Among them, t detect is the titration inflection point, D c is the empirical correction coefficient, ΔpH(t) is the pH difference between the current moment and the previous moment;

[0121] The corrected termination time t stop End the titration operation early to avoid over-titration caused by delayed sensor response;

[0122] Finally, the titration endpoint position and reagent consumption volume are obtained;

[0123] It should be noted that the method of introducing a delay compensation factor to correct the endpoint time is intended to overcome the problem of overtitration caused by the delayed response of the pH sensor. By using the formula to predict the actual titration termination time in advance and normalizing it with the current titration rate, the accuracy and consistency of the endpoint judgment can be further improved, thereby improving the reliability and repeatability of the titration results.

[0124] S6. Record the experimental data during the process, including the final reagent consumption volume, titration endpoint time and corresponding pH value, and generate a titration process report;

[0125] Furthermore, all experimental data are recorded, including the initial set flow rate, the real-time pressure value of each channel, the actual supply flow rate, the pH value change curve, the titration inflection point time, the actual titration end time, the total reagent consumption volume and the final pH value;

[0126] Integrate the above data into a complete titration process report in a structured manner;

[0127] The report includes titration curve, key time node annotation, reagent usage statistics and system operation status summary;

[0128] It also supports exporting to highly readable data file formats for subsequent analysis and archiving;

[0129] The method for automatically evaluating test repeatability and stability includes the following steps:

[0130] While generating the titration process report, the repeatability and stability indicators of this test are automatically evaluated;

[0131] The evaluation is based on a comparison of historical test data under the same conditions, including comparison of titration endpoint deviation, reagent consumption fluctuation range, and pH response slope consistency between the current test and historical data;

[0132] If any of the above deviations exceed the preset tolerance, it will be marked as an abnormal test;

[0133] and prompt the user to check system status, recalibrate sensors, or change reagent batches;

[0134] This evaluation mechanism continuously monitors test quality and ensures the reliability and repeatability of test results.

[0135] It should be noted that the functional module for recording experimental data and generating titration process reports is not only used to save complete test process data, but also integrates a quality assessment mechanism. Through comparative analysis of historical data, it can automatically identify abnormal test conditions and prompt users to take corresponding measures, thereby realizing closed-loop management of the entire process from data collection, process control to quality monitoring, which helps to improve the intelligence level of equipment and the convenience of operation, and meet the standardized management needs of laboratories.

[0136] This embodiment also provides a constant flow supply system for acid and alkali reagents, comprising:

[0137] Initialization setting module, dynamic control module, inflection point recognition module, rate adjustment module, endpoint correction module and data processing module;

[0138] The initialization setting module is used to set the parameters of the multi-channel pumping system before starting the titration, and start the pressure sensor and flow meter to collect the real-time supply status data of each channel;

[0139] A dynamic control module is used to adjust the pump output based on the collected pressure measurement values ​​and flow data using a dynamic PID feedback control algorithm to maintain a constant flow rate output of acid and base reagents under different load conditions;

[0140] The inflection point recognition module is used to continuously collect pH value change signals during the titration process using a pH sensor based on the stable supply of acid and base reagents, and identify the first and second derivatives of the titration reaction based on the time series analysis method. When the second derivative exceeds the preset threshold, it is determined to be the inflection point of the titration;

[0141] The rate adjustment module is used to call the fuzzy rule library to determine the current titration rate level to be adopted based on the identified first-order derivative and second-order derivative, thereby realizing nonlinear adaptive adjustment of the titration rate;

[0142] The endpoint correction module is used to introduce a delay compensation factor to correct the endpoint time based on the titration inflection point moment determined by the inflection point recognition module and the current titration rate output by the rate adjustment module to obtain the actual titration end time;

[0143] The data processing module is used to record the experimental data generated during the entire test process, including the final reagent consumption volume, titration endpoint time and corresponding pH value, and generate a complete titration process report while evaluating the repeatability and stability of the test.

[0144] This embodiment also provides a computer device suitable for the constant current testing method of acid and base reagents, including: a memory and a processor; the memory is used to store computer-executable instructions, and the processor is used to execute computer-executable instructions to implement the constant current testing method of acid and base reagents proposed in the above embodiment.

[0145] The computer device may be a terminal, comprising a processor, a memory, a communication interface, a display screen and an input device connected via a system bus. The processor of the computer device is used to provide computing and control capabilities. The memory of the computer device comprises a non-volatile storage medium and an internal memory. The non-volatile storage medium stores an operating system and a computer program. The internal memory provides an environment for the operation of the operating system and the computer program in the non-volatile storage medium. The communication interface of the computer device is used to communicate with an external terminal in a wired or wireless manner, and the wireless manner may be achieved through WIFI, an operator network, NFC (near field communication) or other technologies. The display screen of the computer device may be a liquid crystal display or an electronic ink display screen, and the input device of the computer device may be a touch layer covering the display screen, or a button, trackball or touchpad provided on the housing of the computer device, or an external keyboard, touchpad or mouse.

[0146] This embodiment also provides a storage medium having a computer program stored thereon, which, when executed by a processor, implements the acid-base reagent constant current test method proposed in the above embodiment; the storage medium can be implemented by any type of volatile or non-volatile storage device or a combination thereof, such as static random access memory (SRAM), electrically erasable programmable read-only memory (EEPROM), erasable programmable read-only memory (EPROM), programmable read-only memory (PROM), read-only memory (ROM), magnetic memory, flash memory, disk or optical disk.

[0147] In summary, the present invention achieves high stability and consistency of multi-channel reagent supply by introducing a dynamic PID feedback control algorithm, and combines the titration inflection point recognition technology based on time series analysis to significantly improve the sensitivity and accuracy of titration endpoint judgment. At the same time, a fuzzy logic control strategy is adopted to realize nonlinear adaptive adjustment of the titration rate, taking into account both test efficiency and accuracy, and effectively corrects the error caused by sensor response lag by introducing a delay compensation mechanism, further improving the repeatability and reliability of the test results. In addition, the system has complete data recording and quality assessment functions, supports full process traceability and intelligent management, and is suitable for a variety of application scenarios such as microfluidics, automatic titration and online monitoring.

[0148] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention may be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present invention, which should all be included in the scope of the claims of the present invention.

Claims

1. A constant current test method for acid and base reagents, characterized by: include: Before starting the titration, the multi-channel pumping system is initialized and the pressure sensor and flow meter are started to collect the real-time supply status data of each channel; Based on the collected pressure measurement values ​​and flow data, a dynamic PID feedback control algorithm is used to adjust the pump output to maintain a constant flow rate output of acid and base reagents under different load conditions; On the basis of stable supply of acid and base reagents, a pH sensor is used to continuously collect pH value change signals during the titration process, and the first and second derivatives of the titration reaction are identified based on the time series analysis method. When the second derivative exceeds the preset threshold, it is determined as the titration inflection point; Based on the identified first-order derivative and second-order derivative, the fuzzy rule library is called to determine the current titration rate level to be adopted, thereby realizing nonlinear adaptive adjustment of the titration rate; Based on the titration inflection point and the current titration rate, a delay compensation factor is introduced to correct the endpoint time to obtain the actual titration end time; Record experimental data during the process, including final reagent consumption volume, titration endpoint time and corresponding pH value, and generate a titration process report.

2. The acid-base reagent constant current testing method according to claim 1, wherein: The parameter setting in the dynamic PID feedback control algorithm specifically includes the following steps: The historical calibration curve is used to convert the flow rate target Q0 set in the current experiment to obtain the corresponding reference pressure value P ref ; According to the collected pressure measurement value P meas and flow data, calculate error signal; Use the scaling factor K p , integral coefficient K i and differential coefficient K d Performing weighted compensation processing on the error signal; The target output flow rate Q of the current channel is calculated by the following expression target : Among them, Q0 is the initial target flow rate set by the user, P ref is the standard reference pressure obtained by looking up the table or interpolating Q0, P meas is the pressure value collected in real time by the pressure sensor, K p , K i , K d The proportional, integral, and differential coefficients of the PID controller are pre-calibrated according to the system response characteristics; According to the target output flow rate Q target Adjust the pump output voltage or pulse frequency to make the actual supply flow rate approach the set value, so as to achieve constant flow rate output under different load conditions.

3. The acid-base reagent constant current testing method according to claim 2, wherein: The method for identifying titration inflection points based on time series analysis specifically comprises the following steps: On the basis of stable supply of acid and alkali reagents, the pH sensor is used to continuously collect the pH change signal of the solution during the titration process at a fixed sampling frequency fsfs; The collected pH sequence is divided into multiple time windows, each window contains N sampling points; The sliding window method was used to perform a linear fit on the pH values ​​within each window, and the first-order derivative ΔpH within the window was calculated; The first-order derivative ΔpH is defined as the rate of change of pH value within the window, that is: Among them, pH i+1 is the pH value of the i-th and i+1-th sampling points, t i , t i+1 is the corresponding sampling time; Perform sliding window analysis on the first-order derivative sequence again to obtain the second-order derivative Δ 2 pH; The second-order derivative Δ 2 pH represents the changing trend of the first-order derivative and is defined as: Where ΔpH j+1 is the ΔpH of two adjacent windows, t j , t j+1 is the time center point of the corresponding window; When Δ 2 When the absolute value of pH exceeds the preset threshold θ, the current moment is marked as the inflection point of the titration reaction t detect .

4. The constant current test method for acid and base reagents according to claim 3, wherein: The method for adjusting the titration rate by calling the fuzzy rule base specifically comprises the following steps: Based on the first-order derivative ΔpH and the second-order derivative Δ 2 pH, which are normalized to values ​​within the interval [0,1] and used as two input variables of the fuzzy controller; calling a preset fuzzy rule base, wherein the fuzzy rule base includes a plurality of fuzzy sets and corresponding output titration rate levels; When ΔpH is small and Δ 2 When the pH is close to zero, it is judged to be close to the end point area and a low-speed titration instruction is output; When ΔpH is large and Δ 2 If the pH is small, it is judged as a stable reaction area and a high-speed titration instruction is output; After fuzzy reasoning, the titration rate level v that should be adopted currently is output; The output titration rate is used to control the pump driving module to achieve nonlinear adaptive adjustment of the titration rate; The titration process presents an optimized rhythm of fast at the beginning and slow at the end, improving the overall test efficiency and accuracy.

5. The constant current testing method for acid and base reagents according to claim 4, wherein: The method of introducing a delay compensation factor to correct the end time specifically includes the following steps: Based on the titration inflection point t detect , and the average titration rate v corresponding to the current titration rate level; Introducing delay compensation factor D c , the delay compensation factor is pre-calibrated according to the system response time and sensor hysteresis characteristics; The actual titration end time t is calculated using the following formula: stop : t stop =t detect -D c ·ΔpH(t); Among them, t detect is the titration inflection point, D c is the empirical correction coefficient, ΔpH(t) is the pH difference between the current moment and the previous moment; The corrected termination time t stop End the titration operation early to avoid over-titration caused by delayed sensor response; Finally, the titration endpoint position and reagent consumption volume are obtained.

6. The constant current testing method for acid and base reagents according to claim 5, wherein: The method for recording experimental data and generating a titration process report specifically comprises the following steps: Record all experimental data, including the initial set flow rate, real-time pressure values ​​of each channel, actual supply flow rate, pH value change curve, titration inflection point, actual titration end time, total reagent consumption volume and final pH value; Integrate the above data into a complete titration process report in a structured manner; The report includes titration curve, key time node annotation, reagent usage statistics and system operation status summary; It also supports exporting to highly readable data file formats for subsequent analysis and archiving.

7. The constant current testing method for acid and base reagents according to claim 6, wherein: The method for automatically evaluating test repeatability and stability specifically comprises the following steps: While generating the titration process report, the repeatability and stability indicators of this test are automatically evaluated; The evaluation is based on comparison of historical test data under the same conditions, including comparison of titration endpoint deviation, reagent consumption fluctuation range, and pH response slope consistency between the current test and historical data; If any of the above deviations exceed the preset tolerance, it will be marked as an abnormal test; and prompt the user to check system status, recalibrate sensors, or change reagent batches; This evaluation mechanism continuously monitors test quality and ensures the reliability and repeatability of test results.

8. A constant current supply system for acid and base reagents, based on the constant current testing method for acid and base reagents according to any one of claims 1 to 7, characterized in that: include: Initialization setting module, dynamic control module, inflection point recognition module, rate adjustment module, endpoint correction module and data processing module; The initialization setting module is used to set parameters of the multi-channel pumping system before starting titration, and to start the pressure sensor and flow meter to collect real-time supply status data of each channel; The dynamic control module is used to adjust the pump output based on the collected pressure measurement value and flow data using a dynamic PID feedback control algorithm to maintain a constant flow rate output of the acid and base reagents under different load conditions; The inflection point identification module is used to continuously collect pH value change signals during the titration process using a pH sensor on the basis of a stable supply of acid and base reagents, and identify the first-order derivative and second-order derivative of the titration reaction based on a time series analysis method. When the second-order derivative exceeds a preset threshold, it is determined to be the titration inflection point moment; The rate adjustment module is used to call the fuzzy rule library to determine the titration rate level to be currently adopted based on the identified first-order derivative and second-order derivative, thereby realizing nonlinear adaptive adjustment of the titration rate; The endpoint correction module is used to introduce a delay compensation factor to correct the endpoint time based on the titration inflection point moment determined by the inflection point recognition module and the current titration rate output by the rate adjustment module to obtain the actual titration termination time; The data processing module is used to record the experimental data generated during the entire test process, including the final reagent consumption volume, titration endpoint time and corresponding pH value, and generate a complete titration process report, while evaluating the repeatability and stability of the test.

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