A Multi-channel Feedback Calibration Method for Metering and Dispensing Plastic Particles

Abstract

This invention discloses a multi-channel feedback calibration method for metering and dispensing plastic particles, relating to the field of alarm monitoring technology. The method includes continuously acquiring the weighing readings of each metering channel when at least two types of plastic particles are dispensed simultaneously through multiple parallel metering channels; analyzing the weighing readings of each metering channel to determine whether a deterministic trend indicating future dispensing instability is present; when the weighing reading analysis of the first metering channel indicates that its current dispensing process has not triggered an immediate alarm but has shown a unidirectional deviation trend that will lead to the final dispensing quantity exceeding the tolerance, the first metering channel is marked as a channel requiring priority intervention. This invention achieves personalized adaptation of the trend judgment window, enabling more timely trend identification for channels with poor stability and improving the judgment accuracy for channels with good stability, reducing the lag and false judgment rate of trend identification, and effectively avoiding dispensing deviations caused by lag correction.

Description

Technical Field

[0001] This invention relates to the field of alarm monitoring technology, and more specifically, to a method for metering and dispensing plastic particles with multi-channel feedback calibration. Background Technology

[0002] Metering and batching of plastic particles is a crucial step in the processing of polymer materials, such as injection molding and extrusion. The accuracy of this batching directly affects the physical properties and dimensional stability of the final product. Current multi-channel parallel batching technologies often employ a control mode of real-time weighing and threshold alarms. This means that when the weighing reading of a certain metering channel exceeds the preset error range, an immediate alarm is triggered, and batching is stopped or forced to correct.

[0003] However, in actual production scenarios, factors such as differences in the flowability of plastic particles, mechanical wear of the feeding mechanism, and material bridging can cause the metering channel to exhibit a latent instability trend of unidirectional deviation even before reaching the alarm threshold. Current technology lacks a mechanism to predict and intervene early in such trends, often only making corrections after the weighing reading exceeds the threshold. By this time, some batching has already exceeded the tolerance, requiring re-batching or discarding substandard materials, leading to decreased production efficiency and material waste.

[0004] Meanwhile, traditional multi-channel batching correction strategies often employ a global synchronous adjustment mode. This means that when a deviation occurs in a single channel, the feeding parameters of all parallel channels are modified simultaneously. This ignores the independence of the batching process in each channel and the differences in the correlation of deviations, which can easily lead to cascading deviations and further reduce batching accuracy. In addition, existing correction calculations are mostly based on fixed proportional coefficients, without considering the severity and development stage of the deviation trend. The correction effect lacks specificity and is difficult to quickly offset different types of unidirectional deviation trends. Summary of the Invention

[0005] To address the above problems, this invention provides a multi-channel feedback calibration method for metering and dispensing plastic particles.

[0006] This invention provides a multi-channel feedback calibration method for metering and dispensing plastic particles, comprising: When at least two types of plastic particles are dispensed simultaneously through multiple metering channels connected in parallel, the weighing readings of each metering channel are continuously acquired. Analyze the weighing readings of each metering channel to determine whether there is a definite trend pointing to future batch instability; When the weighing reading analysis of the first metering channel shows that the current batching process has not triggered an immediate alarm but has shown a one-way deviation trend that will lead to the final batching quantity exceeding the tolerance, the first metering channel is marked as the channel that needs to be intervened first. Calculate the first adjustment amount to counteract the trend based on the severity and stage of the unidirectional deviation trend; The first adjustment amount is used to correct the output parameters of the feeding mechanism of the channel that needs to be prioritized for intervention. During the correction of the channel requiring priority intervention, the remaining feeding mechanisms that are not marked as channels requiring priority intervention shall continue to operate with their original parameters.

[0007] Preferably, the weighing readings of each metering channel are analyzed to determine whether a definite trend pointing to future batching instability occurs, specifically including: The continuously acquired weighing readings are captured within a preset time window to obtain the current analysis sequence; A linear fit is performed on the current analysis sequence to obtain a fitted straight line; If the absolute value of the slope of the fitted straight line is greater than a set threshold, and the direction of the slope is consistent with the direction of the deviation of the current cumulative amount of ingredients relative to the target amount of ingredients, then it is determined that the channel has the unidirectional deviation trend.

[0008] Preferably, based on the severity and development stage of the unidirectional deviation trend, a first adjustment amount is calculated to counteract the trend, specifically as follows: Substituting the slope S of the fitted straight line and the duration T from the point on which the unidirectional deviation trend was determined to occur, into the following formula, the first adjustment amount ΔP is calculated: ; in, and This is a gain coefficient preset based on the characteristics of the feeding mechanism.

[0009] Preferably, using the first adjustment amount to correct the output parameters of the feeding mechanism that needs to be prioritized in the channel specifically includes: The feeding mechanism is a vibrating feeder; The first adjustment amount is converted into an adjustment command for the vibration frequency or amplitude of the vibrating feeder; The adjustment instructions are executed in a progressive manner, and after each step of adjustment, a new weighing reading is obtained to assess whether the unidirectional deviation trend has been contained.

[0010] Preferably, the adjustment instructions are executed in a gradual manner, specifically as follows: The total adjustment amount corresponding to the adjustment instruction is divided into multiple adjustment steps that are executed sequentially; Each adjustment step is followed by the next batching cycle.

[0011] Preferably, the method further includes: After completing the correction of the channel that needs priority intervention, continuously monitor the weighing reading of that channel; If the channel does not exhibit the unidirectional deviation trend within a preset number of batching cycles, its priority intervention channel designation is removed, and the output parameters of the channel's feeding mechanism are restored to the baseline before this intervention.

[0012] Preferably, the duration of the preset time window is dynamically determined based on the historical batching stability data of the first metering channel; wherein, the channel with the worse historical batching stability, the shorter the duration of the time window set for the first metering channel.

[0013] Preferably, the gain coefficient and The value of is switched according to the current production stage of the first metering channel: at the beginning of the batch, the first set of conservative coefficients is used; during the stable operation of the batch, the second set of aggressive coefficients is switched; and at the end of the batch, the first set of conservative coefficients is switched back.

[0014] Preferably, before generating the adjustment command, a feasibility assessment is performed: based on historical interference data of the vibrating feeder when adjacent channels are working simultaneously, it is predicted whether executing the first adjustment amount will have an adverse effect on the feeding stability of at least one other metering channel; if an adverse effect is predicted, the first adjustment amount is reduced, and the adjustment command is generated with the reduced adjustment amount.

[0015] Preferably, the division of multiple adjustment steps satisfies the following condition: the absolute value of the adjustment amount corresponding to the first adjustment step is greater than the absolute value of the adjustment amount corresponding to any subsequent adjustment step.

[0016] Beneficial effects: The innovation of this invention lies in the provision of a multi-channel feedback calibration method for metering and dispensing plastic particles. By dynamically determining the duration of the time window based on historical dispensing stability data of the metering channels, the window duration is shorter for channels with poorer stability. This achieves personalized adaptation of the trend determination window, enabling more timely trend identification for channels with poor stability and improving the accuracy of determination for channels with good stability. Compared with the determination method using a fixed time window, this significantly reduces the lag and false judgment rate of trend identification, accurately identifies unidirectional deviation trends that do not trigger immediate alarms, effectively avoids dispensing errors caused by delayed correction, and helps improve dispensing accuracy. Attached Figure Description

[0017] Figure 1 This is a flowchart of the ingredient preparation method of the present invention. Detailed Implementation

[0018] The following specific embodiments further illustrate the multi-channel feedback calibration method for metering and dispensing plastic particles provided by the present invention. These embodiments are merely illustrative of the technical solutions of the present invention and are not intended to limit the scope of protection of the present invention.

[0019] like Figure 1 As shown: A multi-channel feedback calibration method for metering and dispensing plastic particles, comprising: In this embodiment, multiple sets of metering channels connected in parallel are used for simultaneous feeding of at least two types of plastic particles. Each metering channel is equipped with a weighing sensor, a vibrating feeder, and a drive controller. The rated feeding capacity of each metering channel is 50 kg, and the maximum allowable feeding error is ±0.5 kg.

[0020] When at least two types of plastic particles are dispensed simultaneously through multiple metering channels connected in parallel, the weighing readings of each metering channel are continuously acquired.

[0021] Specifically, the weighing sensors in each metering channel establish a data connection with the central controller, transmitting the continuously collected weighing readings to the central controller's buffer unit. It should be noted that, to avoid analysis delays caused by data transmission latency, a data transmission timeout threshold of 300ms is set. When the weighing data from a certain metering channel exceeds the timeout threshold three consecutive times, the local buffer data for that channel is temporarily used for analysis, and a communication error message is triggered.

[0022] Analyze the weighing readings of each metering channel to determine whether there is a definite trend pointing to future batching instability.

[0023] In this step, determining whether a definite trend pointing to future batch instability occurs specifically includes: capturing continuously acquired weighing readings within a preset time window to obtain the current analysis sequence; the duration of the preset time window is dynamically determined based on the historical batch stability data of the first metering channel; wherein, the channel with the worse historical batch stability, the shorter the duration of the time window set for the first metering channel.

[0024] Specifically, the central controller pre-stores historical batching stability data for each metering channel. This data includes indicators such as the frequency of unidirectional deviation trends, the number of deviation corrections, and the batching accuracy compliance rate for each channel in nearly 100 batching processes. A stability score is calculated for each channel using a preset algorithm, with a percentage-based score indicating better historical batching stability and a lower score indicating worse stability. The duration of the time window is measured in units of sampling points. The base duration is set to a time interval containing 30 consecutive sampling points, and is dynamically adjusted based on the stability score. The adjustment rules are as follows: when the stability score is ≥80, the base duration of 30 sampling points is maintained; when the stability score is ≤60 and <80, it is adjusted to 25 sampling points; when the stability score is <60, it is adjusted to 20 sampling points.

[0025] For channels with poorer historical ingredient stability, shorter time windows are preferable to more quickly capture weight change characteristics and promptly identify hidden unidirectional deviation trends, avoiding trend recognition lag caused by excessively long windows. Conversely, for channels with better stability, relatively longer time windows reduce trend misjudgments caused by short-term data fluctuations and improve the accuracy of the judgment results. The time window employs a sliding update mechanism, meaning that for each new weighing reading acquired, the window automatically discards the earliest sampling point, ensuring that the current analysis sequence always reflects the latest ingredient weight change status.

[0026] A linear fit is performed on the current analysis sequence to obtain a fitted straight line. Specifically, the least squares method is used to perform a linear fit on the sampling points in the current analysis sequence. During the fitting process, the sampling time is used as the abscissa and the weighing reading is used as the ordinate. The equation of the fitted straight line is calculated as y = kx + b, where k is the slope of the fitted straight line, reflecting the rate of change of the weighing reading, and b is the intercept. The core calculation logic of the least squares method is to determine the optimal slope k and intercept b by minimizing the sum of squares of the deviations between each sampling point and the fitted straight line, ensuring that the fitting result can accurately reflect the overall trend of the current analysis sequence.

[0027] If the absolute value of the slope of the fitted straight line is greater than a set threshold, and the direction of this slope is consistent with the direction of the deviation of the current cumulative feed amount from the target feed amount, then the channel is determined to have a unidirectional deviation trend. Specifically, the set threshold is calculated based on the maximum allowable feed error and the total feed time, and is set to 0.02 kg / sampling point. The design logic of this value is to ensure that, in a scenario with a rated feed amount of 50 kg and a maximum allowable error of ±0.5 kg, a trend change that could lead to the final deviation can be identified in advance. The deviation direction of the current cumulative feed amount from the target feed amount is divided into two types: positive deviation (current cumulative feed amount > target feed amount for the corresponding stage) and negative deviation (current cumulative feed amount < target feed amount for the corresponding stage). The direction of the slope is determined by the positive or negative value of the slope k. A positive value of k indicates that the weighing reading is on an upward trend, and a negative value of k indicates that the weighing reading is on a downward trend.

[0028] The rule for determining the consistency between the deviation direction and the slope direction is as follows: when the current cumulative feed amount is a positive deviation, if the slope k of the fitted line is positive, then the direction is considered consistent; when the current cumulative feed amount is a negative deviation, if the slope k of the fitted line is negative, then the direction is considered consistent. For example, if the current cumulative feed amount of a metering channel is 18kg, and the corresponding target feed amount for the stage is 15kg (positive deviation), and the slope k of the fitted line is 0.03kg / sampling point (absolute value greater than 0.02kg / sampling point), then the channel is determined to have a unidirectional deviation trend; if the slope k is -0.03kg / sampling point, although the absolute value is greater than the set threshold, the direction is inconsistent with the positive deviation, and it is not determined to be a unidirectional deviation trend.

[0029] In terms of technical effectiveness, this trend analysis method, combined with a dynamically adjusted time window, can more accurately and timely identify potential ingredient instability risks in different stability channels. Compared with the traditional fixed-window trend judgment mode, it provides more time for intervention and adjustment.

[0030] When the weighing reading analysis of the first metering channel shows that the current batching process has not triggered an immediate alarm but has shown a unidirectional deviation trend that will lead to the final batching quantity exceeding the tolerance, the first metering channel is marked as a channel that needs priority intervention.

[0031] Specifically, the trigger condition for an immediate alarm is that the absolute value of the deviation between the current weighing reading and the theoretical ingredient quantity for the corresponding stage is ≥0.3kg. This threshold is set based on 60% of the maximum allowable error in ingredient proportioning, ensuring both alarm sensitivity and avoiding false alarms. Determining a unidirectional deviation trend requires meeting two conditions: first, the current deviation value has not reached the 0.3kg immediate alarm threshold; second, after the above linear fitting and directional consistency determination, it is confirmed that this trend will cause the absolute value of the final ingredient quantity deviation to exceed the maximum allowable error of 0.5kg.

[0032] When both of the above conditions are met simultaneously, the central controller marks the metering channel as a channel requiring priority intervention and sets the corresponding flag bit in the system status register. The effective duration of the flag bit is from the time of marking until five sampling points after the correction is completed and the trend stabilizes. This effective duration is understood to avoid repeated marking and frequent corrections due to short-term data fluctuations, ensuring the stability of the adjustment process. Simultaneously, the central controller records the output parameters of the vibratory feeder for this channel before the intervention and stores them in the buffer unit as reference parameters, providing a basis for subsequent parameter recovery.

[0033] Based on the severity and stage of the unidirectional deviation trend, calculate the first adjustment amount to counteract the trend.

[0034] Furthermore, based on the severity and development stage of the unidirectional deviation trend, a first adjustment amount to counteract this trend is calculated. Specifically, the slope S of the fitted straight line and the duration T since the unidirectional deviation trend was determined to have occurred are substituted into the following formula to calculate the first adjustment amount ΔP: ΔP = K1 × |S| + K2 × T, where K1 and K2 are gain coefficients preset according to the characteristics of the feeding mechanism. The values ​​of the gain coefficients K1 and K2 are switched according to the current production stage of the first metering channel: at the beginning of the batch, the first set of conservative coefficients is used; during the stable operation stage of the batch, the second set of aggressive coefficients is switched; and at the end of the batch, the first set of conservative coefficients is switched back.

[0035] Specifically, the central controller divides the production stage according to the proportion of the cumulative batch amount to the total batch amount. The division rule is as follows: when the cumulative batch amount is ≤20%, it is determined to be the start stage of the batch; when 20% < cumulative batch amount is <80%, it is determined to be the stable operation stage of the batch; when the cumulative batch amount is ≥80%, it is determined to be the end stage of the batch. This division rule is suitable for the production characteristics of batch batches. During the start and end stages of the batch, the batching system is easily affected by factors such as material feeding and changes in silo level, resulting in poor stability. During the stable operation stage of the batch, the system is stable and has higher tolerance for deviation adjustment.

[0036] The first set of conservative coefficients is used to adapt to the start and end stages of the batch. These coefficients are smaller, reducing the weighted impact of slope and duration on the adjustment amount and avoiding over-adjustment due to system fluctuations. In this embodiment, the first set of conservative coefficients is set to K1=30 and K2=0.03. The second set of aggressive coefficients is used to adapt to the stable operation stage of the batch. These coefficients are larger, amplifying the weighted impact of slope and duration on the adjustment amount, enabling rapid and precise adjustment of unidirectional deviation trends and timely curbing the development of deviations. In this embodiment, the second set of aggressive coefficients is set to K1=50 and K2=0.05. Both sets of coefficients were determined through prior calibration tests to match the adjustment response characteristics of the vibrating feeder with the batching characteristics of the plastic particles, ensuring that the adjustment amount at different production stages can adapt to the actual batching requirements.

[0037] The central controller calculates in real time the proportion of the cumulative feed amount in the first metering channel to the total feed amount in a single batch, automatically determines the current production stage, and completes the real-time switching of K1 and K2. Coefficient switching and adjustment calculation are performed synchronously, requiring no manual intervention and ensuring the dynamic adaptability of the adjustment amount. The slope S of the fitted straight line is the slope of the fitted straight line obtained by least squares fitting when determining a unidirectional deviation trend. Its unit is kg / sampling point, directly reflecting the rate of change of the unidirectional deviation trend. |S| is the absolute value of this slope; the larger the value, the faster the unidirectional deviation trend develops, and the greater the corresponding adjustment amount required to counteract this trend.

[0038] The duration T from the onset of a unidirectional deviation trend is measured in units of sampling points. The timing begins when the central controller completes the determination of the unidirectional deviation trend and outputs the determination result. The value of duration T increases by 1 for each additional valid weighing sampling point. This duration directly reflects the degree of the unidirectional deviation trend. The larger the value of duration T, the longer the trend has been developing, the higher the risk of the ingredient quantity exceeding the tolerance, and the greater the corresponding adjustment requirement.

[0039] The calculation logic of the first adjustment amount ΔP is to comprehensively consider the development speed and duration of the unidirectional deviation trend, and combine the dynamic coefficient weighting of the production stage. The calculation result can accurately match the adjustment needs of the unidirectional deviation trend in different production stages, different severity levels, and different duration stages. This avoids excessive adjustment during the batch start-up and shutdown stages, and achieves rapid adjustment during the stable operation stage.

[0040] In this embodiment, if the slope of the fitted straight line is S=0.04kg / sampling point when a unidirectional deviation trend is determined during the stable operation phase of the batch, and the duration of the trend from its occurrence is T=8 sampling points, the second set of positive coefficients K1=50 and K2=0.05 are used. Substituting these values ​​into the formula, we get ΔP=50×|0.04|+0.05×8=2+0.4=2.4kg. If the trend occurs at the beginning of the batch, the first set of conservative coefficients K1=30 and K2=0.03 are used. Substituting these values ​​into the formula, we get ΔP=30×|0.04|+0.03×8=1.2+0.24=1.44kg. The adjustment amounts at different production stages are adapted to the actual production status, improving the accuracy of the correction.

[0041] Use the first adjustment amount to correct the output parameters of the feeding mechanism that needs to be prioritized in the channel.

[0042] In actual implementation, the first adjustment amount is used to correct the output parameters of the feeding mechanism in the channel that needs priority intervention. Specifically, this includes: before generating the adjustment command, a feasibility assessment is performed: based on historical interference data of the vibrating feeder when working simultaneously in adjacent channels, it is predicted whether executing the first adjustment amount will adversely affect the feeding stability of at least one other metering channel; if an adverse effect is predicted, the first adjustment amount is reduced, and the adjustment command is generated with the reduced adjustment amount. The feeding mechanism is a vibrating feeder; the first adjustment amount is converted into an adjustment command for the vibration frequency or amplitude of the vibrating feeder; the adjustment command is executed in a gradual manner, and after each step of adjustment, a new weighing reading is obtained to assess whether the unidirectional deviation trend has been curbed.

[0043] The adjustment instructions are executed in a progressive manner, specifically by dividing the total adjustment amount corresponding to the adjustment instructions into multiple adjustment steps to be executed sequentially. After each adjustment step is executed, the next batching cycle begins. The division of multiple adjustment steps satisfies the following condition: the absolute value of the adjustment amount corresponding to the first adjustment step is greater than the absolute value of the adjustment amount corresponding to any subsequent adjustment step.

[0044] Specifically, the central controller pre-stores historical interference data of each vibrating feeder when they are working simultaneously in adjacent channels. This data includes interference-related indicators such as the fluctuation value of the feeding accuracy of adjacent channels, the trigger frequency of unidirectional deviation trends, and the rate of change of conveying speed under different channel combinations and different vibration parameter adjustment amplitudes. At the same time, an interference impact assessment model is established. The model takes the adjustment amount of the channel to be adjusted and the vibration parameter adjustment type as inputs and the impact level of the feeding stability of adjacent channels as outputs. The impact level is divided into three levels: no impact, slight impact, and adverse impact. The criteria for judging adverse impact are that the fluctuation value of the feeding accuracy of adjacent channels is ≥0.1% or the rate of change of conveying speed is ≥2%.

[0045] The process of adjusting feasibility prediction is as follows: The central controller inputs the calculated first adjustment amount ΔP and the corresponding vibration parameter adjustment type into the interference influence assessment model. At the same time, it retrieves the information of the metering channels that are currently adjacent to the first metering channel and are in operation. The model calculates the impact level of this adjustment on the feeding stability of each adjacent channel. If the impact level of all adjacent channels is no impact or slight impact, it is determined that executing the first adjustment amount will not have an adverse effect, and the subsequent adjustment instructions are generated directly with the original first adjustment amount. If the impact level of any adjacent channel is an adverse effect, it is determined that executing the first adjustment amount will have an adverse effect, and the first adjustment amount is reduced.

[0046] The adjustment amount reduction adopts a step-wise reduction rule, and the reduction coefficient is determined according to the degree of adverse effect. In this embodiment, if a single adjacent channel has an adverse effect, the reduction coefficient is 0.7; if two or more adjacent channels have an adverse effect, the reduction coefficient is 0.5. The reduced adjustment amount ΔP' = ΔP × reduction coefficient. The value of the reduction coefficient is calibrated through multiple sets of interference tests in the early stage to ensure that the reduced adjustment amount effectively curbs the unidirectional deviation trend of the first metering channel while controlling the impact on the feeding stability of adjacent channels within a slight range. After the reduction is completed, the reduced adjustment amount ΔP' is used as the new adjustment amount to generate subsequent adjustment instructions.

[0047] The vibrating feeder is an electromagnetic vibrating feeder with a vibration frequency adjustment range of 50-100Hz and an amplitude adjustment range of 0.1-1.0mm. The adjustment of vibration frequency and amplitude is achieved by the pulse signal output by the drive controller. The duty cycle of the pulse signal is linearly positively correlated with the vibration frequency and amplitude of the vibrating feeder. The larger the duty cycle, the higher the vibration frequency and the larger the amplitude, and the faster the corresponding material conveying rate. Conversely, the smaller the duty cycle, the slower the material conveying rate.

[0048] The first adjustment amount is converted into an adjustment command for the vibration frequency or amplitude of the vibrating feeder. Specifically, the adjustment type is first determined based on the deviation direction of the unidirectional deviation trend. When the current cumulative batching amount has a positive deviation, the material conveying rate of the vibrating feeder needs to be reduced, corresponding to the generation of an adjustment command to reduce the vibration frequency or amplitude. When the current cumulative batching amount has a negative deviation, the material conveying rate of the vibrating feeder needs to be increased, corresponding to the generation of an adjustment command to increase the vibration frequency or amplitude. If the first adjustment amount is reduced after the feasibility of adjustment is predicted, the conversion is based on the reduced adjustment amount ΔP'. Then, based on the mapping relationship between the batching amount adjustment and the vibration parameter adjustment obtained from the previous calibration test, the adjustment amount is converted into a specific vibration frequency adjustment value Δf or amplitude adjustment value ΔA. The mapping relationship is obtained by fitting multiple sets of experimental data. In this embodiment, the vibration frequency adjustment value Δf = adjustment amount × 2Hz / kg, and the amplitude adjustment value ΔA = adjustment amount × 0.2mm / kg. Technicians can choose the vibration frequency or amplitude as the main adjustment parameter according to the actual batching requirements, or they can combine the two for adjustment.

[0049] Specifically, the total adjustment amount corresponding to the adjustment command is the aforementioned vibration frequency adjustment value Δf or amplitude adjustment value ΔA. The total adjustment amount is divided into 3-5 sequentially executed adjustment steps in a non-equidistant manner. The division rule satisfies that the absolute value of the adjustment amount corresponding to the first adjustment step is greater than the absolute value of the adjustment amount corresponding to any subsequent adjustment step. The absolute values ​​of the adjustment amounts of subsequent adjustment steps are set in an equidistant or progressively decreasing manner. In this embodiment, when the total adjustment amount is divided into 4 adjustment steps, the first adjustment step accounts for 40% of the total adjustment amount, and the remaining 3 adjustment steps each account for 20% of the total adjustment amount. The design consideration of this division method is to quickly curb the development of the unidirectional deviation trend through the first larger adjustment, and to achieve fine correction of the deviation through subsequent smaller adjustments, while avoiding system fluctuations caused by a single large adjustment, thus balancing the efficiency and stability of the correction. The batching cycle is a fixed time interval for the metering channel to complete one quantitative batching, which is determined by the system's preset batching rate and single batching amount. In this embodiment, a single batching cycle is set to a time interval containing 10 sampling points to ensure that there is sufficient batching time to reflect the adjustment effect after each step adjustment.

[0050] During execution, the drive controller first outputs a pulse signal corresponding to the first adjustment step, completing the first step adjustment of the vibration frequency or amplitude. This adjustment step is the one with the largest absolute value of adjustment among all step steps. Subsequently, the metering channel enters the next complete batching cycle and batches materials according to the adjusted vibration parameters. After the batching cycle ends, pulse signals corresponding to subsequent adjustment steps are output sequentially to complete the subsequent step adjustments. Each completed adjustment step enters the next batching cycle, and so on, until all adjustment steps are completed. The execution of each adjustment step is precisely matched with the batching cycle, ensuring that the adjustment action is completed at the switching node of the batching cycle, avoiding material conveying fluctuations caused by parameter adjustments within a single batching cycle.

[0051] After each step adjustment, a new weighing reading is obtained to assess whether the unidirectional deviation trend has been curbed. Specifically, after completing one adjustment step and running the corresponding batching cycle, the central controller obtains all weighing readings within the batching cycle as new analysis data. The time window after dynamic adjustment is re-examined according to the trend determination method described above, linear fitting is performed, and a new fitted line slope S' is obtained. At the same time, the corresponding K1 and K2 coefficients are matched according to the current production stage. The trend curbing effect is evaluated by comparing the change of S' with the original fitted line slope S. If |S'| < |S| and the consistency between the direction of S' and the original deviation direction weakens, the unidirectional deviation trend is initially contained, and subsequent adjustment instructions continue to be executed according to the adjustment step size. If |S'| ≥ |S| or the direction of S' is still highly consistent with the original deviation direction, the adjustment strength of the current adjustment step size is insufficient, and the value of the subsequent adjustment step size is appropriately increased in the next batching cycle. If |S'| ≤ 0.01 kg / sampling point, that is, the absolute value of the slope of the new fitted straight line is less than 50% of the trend judgment threshold, the unidirectional deviation trend is effectively contained, and the remaining adjustment steps are immediately stopped, maintaining the current vibration parameters in the subsequent batching cycle. If the first adjustment amount was reduced in the early stage, when evaluating the trend containment effect, the adjustment strength is comprehensively judged in conjunction with the reduction coefficient to avoid insufficient adjustment due to reduction.

[0052] In this embodiment, if the first adjustment amount ΔP = 2.4 kg during the stable operation phase of the batch, and the feasibility of adjustment is determined to have no adverse effects, and the current cumulative feed amount is a positive deviation, then the vibration frequency is selected as the adjustment parameter. The total adjustment value of the vibration frequency Δf = 2.4 kg × 2 Hz / kg = 4.8 Hz. The total adjustment amount is divided into 4 adjustment steps, with the first adjustment step being 1.92 Hz and the subsequent 3 adjustment steps being 0.96 Hz each. The feed cycle consists of 10 sampling points. The drive controller first reduces the vibration frequency by 1.92Hz, and the metering channel enters the next batching cycle of 10 sampling points. After the batching cycle ends, a new weighing reading is obtained and S' = 0.025kg / sampling point is calculated. |S'| < |S| = 0.04kg / sampling point, indicating that the trend has been initially contained. The vibration frequency is then reduced by 0.96Hz each time, and the next batching cycle begins after each adjustment, until |S'| ≤ 0.01kg / sampling point. The remaining adjustment steps are then stopped, completing the correction of the channel that needs priority intervention.

[0053] During the correction of the priority intervention channel, the other feeding mechanisms that are not marked as priority intervention channels shall continue to operate with the original parameters.

[0054] Specifically, when the central controller marks the channel requiring priority intervention and performs a correction operation, it keeps the output parameters of the vibratory feeders in the remaining unmarked channels locked. The lock signal continues until the correction completion signal of the channel requiring priority intervention is triggered. This locking state is achieved by prohibiting parameter writing commands, ensuring that the vibration frequency, amplitude, and other parameters of the remaining channels are not disturbed by the correction process of the priority channel. At the same time, combined with the feasibility prediction of the previous adjustment, it further avoids the adverse effects of the correction operation on the feeding stability of adjacent channels.

[0055] Understandably, the core design principle of keeping the remaining channels running at their original parameters is to respect the independence of the batching process in each metering channel, and to avoid disrupting the batching balance of other channels due to adjustments in a single channel. For example, in a scenario where multiple sets of plastic particles are batched in a fixed ratio, if the parameters of other channels are adjusted simultaneously due to the adjustment of one channel, the final mixing ratio may deviate from the preset value, affecting product quality.

[0056] In addition, during the correction period, the central controller continuously monitors the weighing readings and trend changes of the remaining unmarked channels. If a new unidirectional deviation trend is found in an unmarked channel due to external interference, it is marked as a secondary intervention channel. After the correction of the current priority intervention channel is completed, the same process is followed to ensure that the batching accuracy of all channels can be guaranteed.

[0057] The method also includes: after completing the correction of the channel that needs priority intervention, continuously monitoring the weighing reading of the channel; if the channel does not show a unidirectional deviation trend within a preset number of batching cycles, then remove the mark of the channel that needs priority intervention and restore the output parameters of the feeding mechanism of the channel to the benchmark before this intervention.

[0058] After completing the correction of the channel that needs priority intervention, the central controller continues to collect and analyze the weighing readings of that channel in real time. The analysis still uses a time window dynamically determined based on the historical batching stability data of that channel. At the same time, the gain coefficients K1 and K2 are automatically switched according to the current production stage. If the adjustment amount was reduced in the early stage, the feeding stability of adjacent channels will be continuously monitored to ensure that the correction operation has no subsequent adverse effects. This continuous monitoring process is carried out in sync with the routine monitoring of other metering channels and does not affect the overall operating efficiency of the batching system.

[0059] The preset number of batching cycles is set based on the production stability and trend recurrence probability of the batching system. In this embodiment, it is set to 5-8 consecutive batching cycles. This value is designed to balance the effectiveness of monitoring and the efficiency of production, avoiding accidental stability misjudgments due to too few preset cycles, and preventing baseline parameter recovery lag due to too many preset cycles. During continuous monitoring, if the channel is determined to show a unidirectional deviation trend again in any batching cycle, monitoring is immediately terminated, the channel that needs priority intervention is maintained, and the adjustment amount is recalculated and correction operation is performed according to the aforementioned method. If the channel does not show a unidirectional deviation trend after multiple trend judgments within a preset number of consecutive batching cycles, it is determined that the batching status of the channel has returned to stability, and it is not necessary to continue to maintain the corrected parameters.

[0060] Once the batching status of the channel is determined to have stabilized, the central controller first clears the priority intervention flag for that channel in the system status register, removes the priority monitoring and correction priority for that channel, and restores it to the monitoring status of a regular metering channel. Subsequently, the central controller retrieves the reference parameters of the vibrating feeder stored in the cache unit before this intervention, generates a parameter recovery command, and sends it to the drive controller. After receiving the command, the drive controller accurately restores the vibration frequency or amplitude of the vibrating feeder in that channel to the reference parameters before the intervention at the switching node at the end of the current batching cycle. The recovery action is completed at the batching cycle switching node, avoiding material conveying fluctuations caused by parameter adjustments during the batching process.

[0061] After the parameters are restored, the channel performs subsequent batching operations according to the baseline parameters. The central controller continues to monitor it according to the normal logic to ensure the long-term stability of the batching status. In this embodiment, if the channel does not show a unidirectional deviation trend for six consecutive batching cycles after the correction is completed, the priority intervention channel mark is immediately removed, and the vibration frequency is restored from the corrected value to the baseline frequency before the intervention, so that the channel returns to the normal batching status.

[0062] The innovation of this invention lies in the provision of a multi-channel feedback calibration method for metering and dispensing plastic particles. By dynamically determining the duration of the time window based on historical dispensing stability data of the metering channels, the window duration is shorter for channels with poorer stability. This achieves personalized adaptation of the trend determination window, enabling more timely trend identification for channels with poor stability and improving the accuracy of determination for channels with good stability. Compared with the determination method using a fixed time window, this significantly reduces the lag and false judgment rate of trend identification, accurately identifies unidirectional deviation trends that do not trigger immediate alarms, effectively avoids dispensing errors caused by delayed correction, and helps improve dispensing accuracy.

[0063] By switching gain coefficients K1 and K2 based on the current production stage of the metering channel, using conservative coefficients for the start and end stages of a batch and aggressive coefficients for the stable operation stage, the adjustment calculation is adapted to different stages. The conservative coefficients avoid over-adjustment caused by system state fluctuations during the start and stop stages of a batch, while the aggressive coefficients enable rapid and accurate containment of unidirectional deviation trends during the stable operation stage. Combined with the calculation formula, the adjustment can accurately match the deviation trends of different production stages and different degrees of severity, solving the problem of lack of scenario adaptability of traditional fixed coefficient correction.

[0064] By predicting the feasibility of adjustment based on historical interference data of adjacent channels before generating adjustment instructions, and reducing the adjustment amount in cases with adverse effects, interference avoidance is achieved when multiple channels are connected in parallel. This avoids the adverse effects of single-channel correction operations on the feeding stability of adjacent channels, takes into account both the deviation correction effect of the target channel and the overall operational stability of the batching system, and solves the problem of chain deviations that are easily triggered in traditional multi-channel batching correction.

[0065] By dividing the total adjustment amount of the adjustment command into non-equidistant adjustment steps where the absolute value of the first step is greater than any subsequent step, and performing gradual adjustments in conjunction with the batching cycle, the deviation trend can be quickly curbed by the first large adjustment, and fine correction can be achieved by subsequent small adjustments. This not only improves the overall efficiency of deviation correction, but also avoids system fluctuations caused by a single large adjustment, balancing correction efficiency and the stability of the batching process, and achieves precise and gentle adjustment of the conveying rate of the vibrating feeder.

[0066] During the correction period, the original parameters of the remaining channels are maintained. Combined with the interference avoidance design based on the feasibility prediction of adjustment, the independence of the batching of each metering channel is respected. This can completely avoid the chain deviation caused by global synchronous adjustment, which is conducive to ensuring the proportional stability of multi-channel batching. At the same time, secondary deviation trends are graded to ensure that the batching accuracy of all channels can be effectively guaranteed.

[0067] By continuously monitoring the weighing readings of the channel after correction, and removing the marker and restoring the baseline parameters before intervention when there is no deviation in the continuous preset quantity batching cycle, closed-loop control of the batching status of the channel after correction is achieved. This avoids the trend recurrence caused by premature parameter restoration due to short-term stability, and also prevents the batching system operation deviation caused by maintaining the corrected parameters for a long time. This ensures that the corrected channel can smoothly return to the normal production state, further improving the robustness and adaptability of the method.

[0068] Meanwhile, by setting detailed designs such as data transmission timeout handling, valid duration of marker bits, matching rules for batching cycle and adjustment step size, and periodic judgment conditions for parameter recovery, combined with four adaptations including dynamic time window, staged gain coefficient, interference avoidance prediction and non-equidistant adjustment step size, the overall practicality of the method is improved. It can adapt to complex production environments such as differences in plastic particle flowability, mechanical wear, batch production stage fluctuations, and multi-channel interference. It can meet the demand for high-precision and high-efficiency batching in the field of polymer material processing, and reduce material waste and production rework rate.

[0069] The above are merely preferred embodiments of the present invention. The scope of protection of the present invention is not limited to the above embodiments. All technical solutions falling within the scope of the present invention's concept are within the scope of protection of the present invention. It should be noted that for those skilled in the art, any improvements and modifications made without departing from the principles of the present invention should also be considered within the scope of protection of this template.

Claims

1. A method for metering and dispensing plastic particles with multi-channel feedback calibration, characterized in that, include: When at least two types of plastic particles are dispensed simultaneously through multiple metering channels connected in parallel, the weighing readings of each metering channel are continuously acquired. Analyze the weighing readings of each metering channel to determine whether there is a definite trend pointing to future batch instability; When the weighing reading analysis of the first metering channel shows that the current batching process has not triggered an immediate alarm but has shown a one-way deviation trend that will lead to the final batching quantity exceeding the tolerance, the first metering channel is marked as the channel that needs to be intervened first. Calculate the first adjustment amount to counteract the trend based on the severity and stage of the unidirectional deviation trend; The first adjustment amount is used to correct the output parameters of the feeding mechanism of the channel that needs to be prioritized for intervention. During the correction of the channel requiring priority intervention, the remaining feeding mechanisms that are not marked as channels requiring priority intervention shall continue to operate with their original parameters.

2. The method for metering and dispensing plastic particles with multi-channel feedback calibration according to claim 1, characterized in that, Analyze the weighing readings of each metering channel to determine whether a definite trend pointing to future batch instability emerges, specifically including: The continuously acquired weighing readings are captured within a preset time window to obtain the current analysis sequence; A linear fit is performed on the current analysis sequence to obtain a fitted straight line; If the absolute value of the slope of the fitted straight line is greater than a set threshold, and the direction of the slope is consistent with the direction of the deviation of the current cumulative amount of ingredients relative to the target amount of ingredients, then it is determined that the channel has the unidirectional deviation trend.

3. The method for metering and dispensing plastic particles with multi-channel feedback calibration according to claim 2, characterized in that, Based on the severity and stage of the unidirectional deviation trend, the first adjustment amount used to counteract the trend is calculated as follows: Substituting the slope S of the fitted straight line and the duration T from the point on which the unidirectional deviation trend was determined to occur into the following formula, the first adjustment amount is calculated. ; in, and This is a gain coefficient preset based on the characteristics of the feeding mechanism.

4. The method for metering and dispensing plastic particles with multi-channel feedback calibration according to claim 1, characterized in that, Using the first adjustment amount, the output parameters of the feeding mechanism of the channel requiring priority intervention are corrected, specifically including: The feeding mechanism is a vibrating feeder; The first adjustment amount is converted into an adjustment command for the vibration frequency or amplitude of the vibrating feeder; The adjustment instructions are executed in a progressive manner, and after each step of adjustment, a new weighing reading is obtained to assess whether the unidirectional deviation trend has been contained.

5. The method for metering and dispensing plastic particles with multi-channel feedback calibration according to claim 4, characterized in that, The adjustment instructions are executed in a gradual manner, specifically as follows: The total adjustment amount corresponding to the adjustment instruction is divided into multiple adjustment steps that are executed sequentially; Each adjustment step is followed by the next batching cycle.

6. The method for metering and dispensing plastic particles with multi-channel feedback calibration according to claim 1, characterized in that, The method further includes: After completing the correction of the channel that needs priority intervention, continuously monitor the weighing reading of that channel; If the channel does not exhibit the unidirectional deviation trend within a preset number of batching cycles, its priority intervention channel designation is removed, and the output parameters of the channel's feeding mechanism are restored to the baseline before this intervention.

7. The method for metering and dispensing plastic particles with multi-channel feedback calibration according to claim 2, characterized in that: The duration of the preset time window is dynamically determined based on the historical batching stability data of the first metering channel; wherein, the channel with the worse historical batching stability, the shorter the duration of the time window set for the first metering channel.

8. The method for metering and dispensing plastic particles with multi-channel feedback calibration according to claim 3, characterized in that, The gain coefficient and The value of is switched according to the current production stage of the first metering channel: at the beginning of the batch, the first set of conservative coefficients is used; during the stable operation of the batch, the second set of aggressive coefficients is switched; and at the end of the batch, the first set of conservative coefficients is switched back.

9. The method for metering and dispensing plastic particles with multi-channel feedback calibration according to claim 4, characterized in that, Before generating the adjustment command, a feasibility assessment is performed: based on historical interference data of the vibrating feeder when it operates simultaneously in adjacent channels, it is predicted whether executing the first adjustment amount will have an adverse effect on the feeding stability of at least one other metering channel; if an adverse effect is predicted, the first adjustment amount is reduced, and the adjustment command is generated with the reduced adjustment amount.

10. A method for metering and dispensing plastic particles with multi-channel feedback calibration according to claim 5, characterized in that, The division of multiple adjustment steps satisfies the following condition: the absolute value of the adjustment amount corresponding to the first adjustment step is greater than the absolute value of the adjustment amount corresponding to any subsequent adjustment step.

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