Joint control method of weight-loss type feeding unit for pharmacy

Abstract

The invention relates to the field of control of weight-loss type feeding machines for pharmacy, in particular to a joint control method of a weight-loss type feeding unit for pharmacy, which comprises the following steps: S1, calculating an expected mass ratio of each slave feeding machine relative to a main feeding machine based on a medicine formula; s2, the actual mass flow of the main feeding machine is collected and obtained; s3, calculating the actual target mass flow rate of each slave feeding machine based on the expected mass proportion of each slave feeding machine relative to the main feeding machine and the actual mass flow rate of the main feeding machine; s4, each slave feeding machine carries out conveying based on the corresponding actual target mass flow calculated in the step S3; and S5, circularly executing the steps S2 to S4, and presetting cycle period time T. According to the joint control method, the actual target mass flow of the auxiliary material feeding machine can be dynamically adjusted and changed on the basis of the actual mass flow of the main feeding machine, so that the proportion accuracy of a medicine formula is improved, and unqualified products are reduced.

Description

Technical Field

[0001] This application relates to the field of control of pharmaceutical loss-in-weight feeders, and in particular to a method for the joint control of pharmaceutical loss-in-weight feeder units. Background Technology

[0002] In modern pharmaceutical manufacturing, especially in the Continuous Manufacturing (CM) model advocated by the US FDA, precise and stable continuous feeding is crucial for ensuring the uniformity of final drug quality. This enables online mixing and granulation of multi-component materials (including active pharmaceutical ingredients (APIs) and various excipients). Loss-in-Weight Feeders, as core equipment for achieving high-precision powder feeding, play a vital role in this process.

[0003] In existing technologies, units consisting of multiple loss-in-weight feeders generally employ an "independent setpoint control" mode, such as... Figure 1 As shown, its working principle is as follows: First, based on the drug formulation, the target mass flow rate (e.g., kg / h) corresponding to each material (main ingredient API, excipient 1, excipient 2, etc.) is calculated. Then, these independent and constant values ​​are used as set points and sent to the independent controllers of each feeder (main feeder and several slave feeders). Each feeder, through its own closed-loop control system (e.g., adjusting the screw speed), makes its actual output flow rate track this preset fixed target value.

[0004] However, this control strategy has inherent and insurmountable technical flaws. The core problem lies in the fact that each feeding unit forms an "information silo," lacking system-level coordination and linkage. In actual production, any feeder, especially the most critical API feeder, may experience batch-to-batch or intra-batch fluctuations in the physical properties of its materials (such as bulk density, flowability, and moisture content), or mechanical disturbances (such as vibration or bridging) causing its instantaneous actual flow rate to deviate from the preset fixed value. At this time, since other excipient feeders are unaware of this situation, they will continue to feed according to their own fixed settings. This directly leads to a real-time deviation in the mass ratio of each component in the material flow entering the downstream mixing unit, compromising one of the key quality attributes (CQA) of pharmaceuticals: "content homogeneity." Once this deviation occurs, it can only be detected using expensive downstream process analysis (PAT) tools, but often it is too late, resulting in the generation of out-of-stock (OOS) products and material waste, posing a significant risk to pharmaceutical quality. Summary of the Invention

[0005] In order to solve the above technical problems, the application provides a control method for a weight-loss type feeder group for pharmaceutical use, which aims to provide a control method for an auxiliary feeder, in which the actual target mass flow of the auxiliary feeder can be dynamically adjusted based on the actual mass flow of the main feeder, so as to improve the accuracy of the proportion of the pharmaceutical formula and reduce the generation of unqualified products.

[0006] The control method for the weight-loss type feeder group for pharmaceutical use provided by the application adopts the following technical scheme:

[0007] The control method for the weight-loss type feeder group for pharmaceutical use comprises the following steps:

[0008] S1, calculating the expected mass proportion of each slave feeder relative to the main feeder based on a pharmaceutical formula;

[0009] S2, collecting and obtaining the actual mass flow of the main feeder;

[0010] S3, calculating the actual target mass flow of each slave feeder based on the expected mass proportion of each slave feeder relative to the main feeder and the actual mass flow of the main feeder, and the calculation formula is as follows:

[0011] SP_slave_dynamic(t) = Flow_actual_master(t) * (Ratio_slave / master);

[0012] wherein SP_slave_dynamic(t) is the actual target mass flow of the slave feeder, Flow_actual_master(t) is the actual mass flow of the main feeder, and Ratio_slave / master is the expected mass proportion of the slave feeder relative to the main feeder;

[0013] S4, each slave feeder is transported based on the corresponding actual target mass flow calculated in step S3;

[0014] S5, steps S2 to S4 are cyclically executed, and a cycle period time T is preset.

[0015] Preferably, the step S2 comprises the following steps:

[0016] S21, collecting the initial mass flow of the main feeder;

[0017] S22, pre-processing the initial mass flow to obtain the actual mass flow of the main feeder.

[0018] Preferably, the step S21 comprises the following steps:

[0019] S211, presetting the basic target mass flow of the main feeder;

[0020] S212, the master feeder delivers based on the base target mass flow rate;

[0021] S213, the initial mass flow rate of the master feeder is collected.

[0022] Preferably, the pre-processing in step S22 includes filtering and denoising.

[0023] Preferably, the filtering in step S22 uses an average filter or a Kalman filter.

[0024] Preferably, the method further comprises:

[0025] The master feeder and all slave feeders are set under the same unified master clock.

[0026] In summary, the present application has the following beneficial technical effects:

[0027] 1. The present application enables the actual target mass flow rate of the auxiliary feeder to be dynamically adjusted based on the actual mass flow rate of the master feeder, thereby improving the accuracy of the proportion of the drug formula and reducing the production of unqualified products.

[0028] 2. The present application improves the accuracy of the proportion of the prepared drug formula and ensures the uniformity of the drug content.

[0029] 3. The present application has high disturbance suppression capability by filtering and denoising the collected initial mass flow rate of the master feeder, thereby greatly enhancing the robustness of the drug preparation process.

[0030] 4. The present application uses modern control theory such as filtering and synchronization, making the system response faster, running more smoothly, and controlling more accurately.

[0031] 5. The present application reduces the influence of human error on the proportion of the prepared drug formula, which conforms to the development direction of intelligent and automated drug production. BRIEF DESCRIPTION OF DRAWINGS

[0032] Figure 1 is prior art in the background art of the present application;

[0033] Figure 2 is a system architecture diagram of the co-control method in the embodiments of the present application;

[0034] Figure 3 is a flowchart of the co-control method in the embodiments of the present application;

[0035] Figure 4 is a comparison chart of the effects of the co-control method in the embodiments of the present application and the prior art method in Figure 1 ​DETAILED DESCRIPTION

[0036] The application will be further described in detail below with reference to the accompanying drawings.

[0037] The application discloses a kind of pharmaceutical weightlessness feeder set's joint control method.

[0038] With reference to Figures 2 to 4 The pharmaceutical weightlessness feeder set's joint control method includes the following steps:

[0039] S1, calculate the expected mass ratio of each slave feeder relative to the master feeder based on the drug formula.

[0040] Specifically, each drug has its specific formula, which includes a main drug component API and several auxiliary components, including auxiliary A, auxiliary B and various auxiliary materials. The formula of the drug includes the specific components and their corresponding proportions. According to the formula, the proportion of each auxiliary (i.e. auxiliary A, auxiliary B and various auxiliary materials) and the main drug component API is calculated, and then the expected mass ratio of each auxiliary in the pharmaceutical process is calculated based on the proportion of the slave feeder relative to the master feeder conveying the main drug component API.

[0041] For example, if the API delivery flow of the master feeder is 0.5 kg / h, and the delivery flow of the auxiliary A corresponding slave feeder is 1.2 kg / h, then the expected mass ratio of auxiliary A is 1.2 / 0.5 = 2.4.

[0042] That is, the delivery flow of the auxiliary A corresponding slave feeder is 2.4 times the delivery flow of the API corresponding master feeder.

[0043] In this way, the expected mass ratio of all auxiliaries relative to the main drug is calculated.

[0044] S2, collect and obtain the actual mass flow of the master feeder;

[0045] Specifically, it includes the following steps:

[0046] S21, collect the initial mass flow of the master feeder;

[0047] Specifically, it includes the following steps:

[0048] S211, preset the basic target mass flow of the master feeder;

[0049] Specifically, the process is mainly the initialization of parameters, in the central processing unit, such as PLC or DCS, set the master feeder basic target mass flow SP_master, the basic target mass flow as a preset value, can provide corresponding reference for subsequent actual conveying flow; and this step can also be placed in step S1 or before step S1.

[0050] S212, the master feeder is based on the basic target mass flow for conveying;

[0051] In use, the master feeder receives the SP_master instruction, and its local controller adjusts the motor speed of the actuator (such as screw, auger) of the master feeder through the conventional closed-loop PID control algorithm, so that the "actual mass flow" (Flow_actual_master) of the master feeder accurately tracks SP_master.

[0052] S213, collecting the initial mass flow of the master feeder.

[0053] Specifically, high-frequency monitoring and collecting data of the master feeder weighing sensor can be used to collect the initial mass flow of the master feeder;

[0054] During the continuous operation of the master feeder, the central processing system or the staff can compare the initial mass flow with the basic target mass flow in real time, and set a certain difference threshold, if the difference threshold between the two is out of limit, it means that the collection system or the weighing sensor of the master feeder may have problems, so that the master feeder can be repaired.

[0055] S22, preprocessing the initial mass flow to obtain the actual mass flow of the master feeder.

[0056] Based on the initial mass flow collected in step S21, a certain preprocessing is performed to obtain the actual mass flow of the master feeder, which is the true mass flow of the master feeder.

[0057] The above preprocessing can include filtering and denoising processes, since the weighing sensor of the master feeder usually uses high sensitivity instruments, it may contain high frequency noise caused by environmental vibration, equipment motor and other factors, if the collected initial mass flow is directly used for calculation, it will cause large deviation of the calculated data, thus greatly affecting the subsequent conveying flow of the feeder, and further causing large error of the proportion of the medicine, resulting in more unqualified medicine. Therefore, for the collected initial mass flow, a digital signal filtering module can be used for filtering and denoising.

[0058] The digital signal filtering module can use a moving average filter or a Kalman filter;

[0059] The moving average filter is used to smooth the initial mass flow of the plurality of master feeders collected in real time, effectively filtering out random noise, extracting a reference signal that can truly reflect the trend of material flow, and then used for calculation from the device set value.

[0060] The Kalman filter adopts Kalman filter algorithm, which is mainly used in application scenarios with extremely high precision requirements. It can give the optimal estimation of system state according to the dynamic model of the system and the measurement data with noise. It can not only provide smooth flow estimation value, but also predict the short-term change trend of flow, so as to realize more forward and accurate control.

[0061] S3, calculating the actual target mass flow of each slave feeder based on the expected mass ratio of each slave feeder relative to the master feeder and the actual mass flow of the master feeder;

[0062] Specifically, the calculation formula of the actual target mass flow of each slave feeder is as follows:

[0063] SP_slave_dynamic(t)=Flow_actual_master(t)*(Ratio_slave / master);

[0064] Wherein, SP_slave_dynamic(t) is the actual target mass flow of the slave feeder, Flow_actual_master(t) is the actual mass flow of the master feeder, and Ratio_slave / master is the expected mass ratio of the slave feeder relative to the master feeder;

[0065] The above process of calculating the actual target mass flow of each slave feeder is continuous, so that the actual target mass flow of each slave feeder is no longer a constant, but a dynamic variable that changes in real time following the actual mass flow of the master feeder.

[0066] S4, each slave feeder transports based on the corresponding actual target mass flow calculated in step S3;

[0067] Specifically, each slave feeder transports based on the actual target mass flow of the corresponding auxiliary material calculated by itself, so as to dynamically follow the actual mass flow of the master material to transport the corresponding auxiliary material, and improve the accuracy of the formula ratio.

[0068] S5, steps S2 to S4 are executed in cycles, and a cycle period time T is preset.

[0069] Specifically, the above steps S2 to S4 are repeatedly executed in cycles, and the cycle period time T is preset.

[0070] In addition, during use, the system sets the master feeder and all slave feeders under the same unified master clock when starting and conveying materials, and the master clock is throughout the entire pharmaceutical process, and the preset cycle time T can be dynamically adjusted according to the equipment or production needs, such as 20 milliseconds, 25 milliseconds, etc.

[0071] By setting the master feeder and all slave feeders under the same unified master clock, at the beginning of each cycle, the central controller synchronously completes the sampling, filtering calculation of the initial mass flow of the master feeder, and simultaneously broadcasts the newly calculated dynamic set value of the actual target mass flow of the auxiliary material corresponding to all slave feeders to the controllers of the slave feeders. This synchronization mechanism ensures that the actions of all devices are carried out under the unified "beat", achieving high-precision dynamic response.

[0072] In addition, in step S4, in order to further improve the accuracy of the pharmaceutical formula, the initial mass flow of each slave feeder can also be collected and the actual mass flow of the slave feeder can be obtained after filtering processing. Since the actual target mass flow of each slave feeder dynamically changes in response to the actual mass flow of the master feeder, each slave feeder has its own device limitations, such as a certain error value. Although the error value is within the controllable or acceptable range of the pharmaceutical formula, the accumulated error over time will affect the pharmaceutical formula proportion. Therefore, after obtaining the actual mass flow of the slave feeder, the actual mass flow of the slave feeder is divided by the obtained actual target mass flow of the slave feeder to obtain the ratio of the actual mass flow of the slave feeder to the obtained actual target mass flow of the slave feeder, which is recorded as an error ratio. The error ratio is the conveying error of the slave feeder. In order to improve the accuracy of the pharmaceutical formula proportion, the calculated actual target mass flow of the slave feeder is used as the actual mass flow of the slave feeder, and then the calculated actual target mass flow of the slave feeder is divided by the error ratio to obtain new data, which is recorded as a correction target mass flow. Finally, the correction target mass flow is used as the new actual target mass flow data of the slave feeder and input into the controller of the slave feeder, thereby further improving the accuracy of the pharmaceutical formula proportion.

[0073] During use, the error ratio of the slave feeder is usually constantly changing at different time periods, and the error ratio can also be constantly updated and iterated.

[0074] The above are preferred embodiments of the present application, which do not limit the protection scope of the present application, therefore: any equivalent changes made on the structure, shape, principle of the present application should be covered within the protection scope of the present application.

Claims

1. A control method for a pharmaceutical loss-in-weight feeder unit, characterized in that, Includes the following steps: S1. Calculate the expected mass ratio of each feeder relative to the main feeder based on the drug formulation; S2. Collect and obtain the actual mass flow rate of the main feeder; S3. Calculate the actual target mass flow rate of each slave feeder based on the expected mass ratio of each slave feeder relative to the main feeder and the actual mass flow rate of the main feeder. The calculation formula is as follows: SP_slave_dynamic(t)=Flow_actual_master(t)*(Ratio_slave / master); Where SP_slave_dynamic(t) is the actual target mass flow rate of the slave feeder, Flow_actual_master(t) is the actual mass flow rate of the master feeder, and Ratio_slave / master is the expected mass ratio of the slave feeder relative to the master feeder. S4. Each feeder delivers the corresponding actual target mass flow rate calculated in step S3. S5. Repeat steps S2 to S4, and preset the cycle time T.

2. The control method for a pharmaceutical loss-in-weight feeder unit according to claim 1, characterized in that, Step S2 includes the following steps: S21. Collect the initial mass flow rate of the main feeder; S22. Preprocess the initial mass flow rate to obtain the actual mass flow rate of the main feeder.

3. The control method for a pharmaceutical loss-in-weight feeder unit according to claim 2, characterized in that, Step S21 includes the following steps: S211, Preset the basic target mass flow rate of the main feeder; S212, The main feeder conveys the feed based on the basic target mass flow rate; S213. Collect the initial mass flow rate of the main feeder.

4. The control method for a pharmaceutical loss-in-weight feeder unit according to claim 2, characterized in that, The preprocessing in step S22 includes filtering and noise reduction.

5. The control method for a pharmaceutical loss-in-weight feeder unit according to claim 4, characterized in that, The filtering in step S22 uses an average filter or a Kalman filter.

6. The control method for a pharmaceutical loss-in-weight feeder unit according to claim 1, characterized in that, Also includes: Set the main feeder and all slave feeders to the same unified master clock.

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