CN117272243A - Dynamic metering precision estimation method based on weightless screw rotating speed data - Google Patents

Abstract

The invention provides a dynamic metering accuracy estimation method based on weightless screw rotating speed data. The dynamic metering precision estimation method based on the weightless screw rotating speed data comprises the following steps: extracting and segmenting actual rotation speed data of the screw; performing linear regression analysis on screw rotation speed data according to the segmented data; predicting the theoretical rotating speed of the screw rod in the feeding stage according to the linear regression analysis result; and calculating the dynamic metering precision of the screw period. The method for estimating the dynamic metering precision based on the rotating speed data of the weightless screw can solve the problems that the existing weightless screw is low in dynamic metering precision and the accuracy of ingredients is affected.

Description

Dynamic measurement accuracy estimation method based on loss-in-weight screw speed data

Technical field

The present invention relates to the technical field of loss-in-weight scales, and specifically, to a dynamic measurement accuracy estimation method based on loss-in-weight scale screw speed data.

Background technique

In the industrial field, in order to ensure the consistency of the product, the proportion of materials must be strictly implemented according to the formula, so the materials need to be accurately measured, such as the preparation of lithium batteries. In continuous production equipment, the feeding system uses a loss-in-weight scale to continuously feed materials at a set flow rate. The existing technology operates in volumetric mode during the replenishing phase of the loss-in-weight scale and the stable phase after replenishing, that is, the discharging screw operates according to the speed at the moment before replenishing the material or the average speed at the previous moment. Only the weight data is recorded, and no Provide closed-loop feedback, and the feeding stage is a metering blind area.

In the prior art known to the inventor, the dynamic measurement accuracy is calculated based on the change in weight loss during the non-feeding stage, which cannot truly reflect the actual dynamic measurement accuracy and greatly affects the accuracy of the ingredients.

Contents of the invention

The main purpose of the present invention is to provide a dynamic measurement accuracy estimation method based on the screw speed data of a loss-in-weight scale, which can solve the problem of low dynamic measurement accuracy of existing loss-in-weight scales and affecting the accuracy of batching.

In order to achieve the above objectives, according to one aspect of the present invention, a dynamic measurement accuracy estimation method based on loss-in-weight screw speed data is provided, including:

Extract and segment the actual screw speed data;

Perform linear regression analysis of screw speed data based on segmented data;

Predict the theoretical screw speed during the feeding stage based on the linear regression analysis results;

Calculate screw cycle dynamic metering accuracy.

Further, the steps of extracting and segmenting the screw speed data include:

Set the trigger interval between two adjacent feedings as one cycle;

Divide the actual speed data of the loss-in-weight weighing screw collected in one cycle into two data sequences V ₁ and V ₂ , corresponding to the volume mode section and the closed-loop control section respectively;

Divide the actual screw speed V ₂ in the closed-loop control section into two data sequences V ₂₁ and V ₂₂ .

Further, the step of dividing the actual screw speed V ₂ of the closed-loop control section into two data sequences V ₂₁ and V ₂₂ includes:

Taking the minimum value of the actual screw speed sequence V ₂ in the closed-loop control section as the dividing point J, divide the actual screw speed V ₂ in the closed-loop control section into two data sequences V ₂₁ and V ₂₂ .

Further, the step of performing linear regression analysis of screw speed data based on segmented data includes:

Perform linear regression analysis on the data sequence V ₂₂ to obtain the regression straight line of the closed-loop control section;

Estimate the theoretical screw speed between the completion time of feeding and the dividing point J based on the regression line

Further, the step of predicting the theoretical screw speed in the feeding stage based on the linear regression analysis results includes:

Based on the actual screw speed at the moment before feeding and the estimated actual screw speed at the time when feeding is completed, linear regression is performed to estimate the theoretical screw speed during the feeding stage.

Further, the step of performing linear regression based on the actual screw speed at the moment before feeding and the estimated actual screw speed at the time when feeding is completed includes:

Determine the theoretical screw speed straight line in the second half of the feeding period based on the regression straight line between the completion time of feeding and the dividing point J moment;

Determine the time point of the maximum weight loss value;

Determine the time point of the minimum theoretical screw speed based on the time point of the maximum loss-in-weight value;

Determine the theoretical screw speed corresponding to the time point at which the theoretical screw speed is minimum based on the theoretical screw speed straight line in the second half of feeding;

The actual screw speed straight line in the first half of feeding is determined based on the actual screw speed at the moment before feeding and the theoretical screw speed corresponding to the time point at which the theoretical screw speed is minimum.

Further, the screw periodic dynamic metering accuracy e is calculated by the following formula:

Where {V ₁ , V ₂₁ } is the set of data sequences V ₁ and V ₂₁ , For data sequence/> is a set of , sum is the summation function, τ is the time between the start of feeding and the dividing point J, and T is the cycle time.

Further, the dynamic measurement accuracy estimation method also includes:

Obtain multiple continuous periodic dynamic measurement accuracy;

Calculate the dynamic measurement accuracy of the loss-in-weight weighing screw speed data based on multiple consecutive periodic dynamic measurement accuracy.

Furthermore, the volume mode section is the constant speed stage of the actual screw speed, and the closed-loop control section is the variable speed stage of the actual screw speed.

Further, before the step of performing linear regression analysis of screw speed data based on segmented data, it also includes:

Obtain the stabilization time t1 when the actual screw speed is in the uniform speed stage after the feeding is completed;

Get the feeding time t2;

Get the ratio t1/t2 of t1 and t2;

When t1/t2≤1/4,

The steps for linear regression analysis of screw speed data based on segmented data include:

Perform linear regression analysis on the data sequence V ₂₂ , and estimate the actual screw speed at the breaking point J based on the regression line;

The steps to predict the theoretical screw speed during the feeding stage based on the linear regression analysis results include:

According to the actual screw speed at the moment before feeding and the actual screw speed at the dividing point J, a linear regression is performed to estimate the theoretical screw speed during the feeding stage.

The steps to calculate the screw cycle dynamic metering accuracy include:

Calculate the periodic dynamic measurement accuracy e through the following formula:

Where {V ₁ , V ₂₁ } is the set of sequences V ₁ and V ₂₁ , sum is the summation function, τ is the time between the start of feeding and the dividing point J, and T is the cycle time.

Applying the technical solution of the present invention, the dynamic measurement accuracy estimation method based on the loss-in-weight screw speed data includes: extracting and segmenting the actual screw speed data; performing linear regression analysis of the screw speed data based on the segmented data; and performing linear regression analysis based on the linear regression analysis results. Predict the theoretical screw speed during the feeding stage; calculate the dynamic measurement accuracy of the screw cycle. This dynamic metering accuracy estimation method segments the actual screw speed data, then uses the determined segmented data to obtain the theoretical screw speed data, and predicts the feeding stage by performing linear regression on the obtained screw theoretical speed data. The theoretical rotation speed of the screw, so that the metering accuracy in the feeding stage, which is a metering blind area, can also be expressed by a linear function, and then the linear function of the feeding stage obtained by linear regression can be used to determine the dynamic metering accuracy in the feeding stage, and calculate the periodic dynamic metering Accuracy, achieving accurate estimation of dynamic measurement accuracy in continuous production, allowing the dynamic precision measurement of loss-in-weight scales to more accurately reflect the true accuracy, greatly improving the accuracy of ingredients.

Description of the drawings

The description and drawings that constitute a part of this application are used to provide a further understanding of the present invention. The illustrative embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the attached picture:

Figure 1 shows a flow chart of a dynamic measurement accuracy estimation method based on loss-in-weight screw speed data according to an embodiment of the present invention;

Figure 2 shows the relationship between the screw speed data and the loss-in-weight weighing amount within one cycle of the dynamic measurement accuracy estimation method based on the loss-in-weight screw speed data of one embodiment of the present invention; and

Figure 3 shows the relationship between the screw speed data and the loss-in-weight weighing weight within one cycle of the dynamic measurement accuracy estimation method based on the loss-in-weight screw speed data according to another embodiment of the present invention.

Detailed ways

It should be noted that, as long as there is no conflict, the embodiments and features in the embodiments of this application can be combined with each other. The present invention will be described in detail below with reference to the accompanying drawings and embodiments.

Referring to Figures 1 to 3, the present invention provides a dynamic measurement accuracy estimation method based on loss-in-weight screw speed data, including:

Extract and segment the actual screw speed data;

Perform linear regression analysis of screw speed data based on segmented data;

Predict the theoretical screw speed during the feeding stage based on the linear regression analysis results;

Calculate screw cycle dynamic metering accuracy.

This dynamic metering accuracy estimation method segments the actual screw speed data, then uses the determined segmented data to obtain the theoretical screw speed data, and predicts the feeding stage by performing linear regression on the obtained screw theoretical speed data. The theoretical rotation speed of the screw, so that the metering accuracy in the feeding stage, which is a metering blind area, can also be expressed by a linear function, and then the linear function of the feeding stage obtained by linear regression can be used to determine the dynamic metering accuracy in the feeding stage, and calculate the periodic dynamic metering Accuracy, achieving accurate estimation of dynamic measurement accuracy in continuous production, allowing the dynamic precision measurement of loss-in-weight scales to more accurately reflect the true accuracy, greatly improving the accuracy of ingredients.

In this embodiment, during the material proportioning process, the actual rotation speed of a part of the screw is consistent with the theoretical rotation speed of the screw. Therefore, the theoretical rotation speed of this part of the screw can be obtained by using a linear regression analysis method based on the changes in the theoretical rotation speed of the screw. The linear function of the rotational speed. After the linear function is determined, the straight line determined by the linear function can be used to infer the theoretical screw rotational speed of the part where the actual screw rotational speed is inconsistent with the theoretical screw rotational speed. In this way, the dynamic accuracy of the feeding stage can be calculated. Measurement provides a basis for calculating the weight change accuracy of the loss-in-weight scale, so that the weight change of the loss-in-weight scale can be calculated based on the dynamic measurement accuracy of the screw speed data of the loss-in-weight scale, and then the material ratio can be adjusted to ensure that the entire cycle The material proportions within the system become controllable with higher precision, which can more effectively improve the accuracy and reliability of material batching.

In one embodiment, the step of extracting and segmenting the screw speed data includes:

Set the trigger interval between two adjacent feedings as one cycle;

Divide the actual speed data of the loss-in-weight weighing screw collected in one cycle into two data sequences V ₁ and V ₂ , corresponding to the volume mode section and the closed-loop control section respectively;

Divide the actual screw speed V ₂ in the closed-loop control section into two data sequences V ₂₁ and V ₂₂ .

In this embodiment, the trigger interval between two adjacent feedings is set as one cycle. The working cycle of the loss-in-weight scale can be divided according to the working principle of the loss-in-weight scale, so that the period division of the loss-in-weight scale matches the working principle of the loss-in-weight scale. The period division is more reasonable, which can obtain more accurate and reliable data in the subsequent dynamic measurement accuracy estimation, and can also effectively reduce the difficulty of dynamic measurement accuracy estimation.

In one embodiment, the volume mode section is the constant speed stage of the actual screw speed, and the closed-loop control section is the variable speed stage of the actual screw speed.

During the working process of the loss-in-weight scale, the screw has a constant speed working stage and a variable speed working stage. The constant speed working stage includes a coexistence stage of feeding and feeding and a separate feeding stage. The variable speed working stage is a separate feeding stage. The constant speed stage and the variable speed working stage of the actual screw speed are used. The speed change stage divides the volume mode section and the closed-loop control section. The linear function of the theoretical screw speed in the closed-loop control section can be determined based on the actual screw speed changes in the closed-loop control section. This linear function can be used to back-develop the independent screw speed in the constant-speed working stage of the screw. The linear function of the feeding stage can then be used to calculate the theoretical screw speed of the feeding and feeding coexistence stages of the screw's uniform working stage by using the linear function of the separate feeding stage at the screw's constant speed working stage and the actual screw speed at the moment before feeding.

In one embodiment, the step of dividing the actual screw speed V ₂ in the closed-loop control section into two data sequences V ₂₁ and V ₂₂ includes:

Taking the minimum value of the actual screw speed sequence V ₂ in the closed-loop control section as the dividing point J, divide the actual screw speed V ₂ in the closed-loop control section into two data sequences V ₂₁ and V ₂₂ .

In one embodiment, the step of performing linear regression analysis of screw speed data based on segmented data includes:

Perform linear regression analysis on the data sequence V ₂₂ to obtain the regression straight line of the closed-loop control section;

Estimate the theoretical screw speed between the completion time of feeding and the dividing point J based on the regression line

In this embodiment, since the minimum value of the actual screw speed sequence V ₂ in the closed-loop control section is the starting point of the consistent stage between the actual screw speed and the theoretical screw speed, the screw in the closed-loop control section can be calculated based on this starting point. The actual rotation speed V ₂ is divided into a data sequence and divided into two data sequences V ₂₁ and V ₂₂ . After being divided into two data sequences, since the minimum value can be determined, and the actual screw speed at the moment before feeding can also be determined, it is equivalent to determining the values of the two endpoints of V _22. In this case, it can be calculated The linear function of the data sequence V ₂₂ , because the linear function of the data sequence V ₂₁ is the same as the linear function of the data sequence V ₂₂ , and the line segment where the data sequence V ₂₁ is located is at the extended end of the line segment where the data sequence V ₂₂ is located, and the two are mutually exclusive. Compared with the dividing point J, therefore, after calculating the linear function of the data sequence V ₂₂ , the linear regression method can be used to infer the regression line of the data sequence V _21. On this basis, the weight loss of the volume mode segment can be further weighed. The screw speed data is estimated to determine the weight loss in the volume mode segment as a linear function of the screw speed.

In one embodiment, the step of predicting the theoretical screw speed during the feeding stage based on the linear regression analysis results includes:

Based on the actual screw speed at the moment before feeding and the estimated actual screw speed at the time when feeding is completed, linear regression is performed to estimate the theoretical screw speed during the feeding stage.

In one embodiment, the step of performing linear regression based on the actual screw speed at the moment before feeding and the estimated actual screw speed at the time when feeding is completed includes:

Determine the theoretical screw speed straight line in the second half of the feeding period based on the regression straight line between the completion time of feeding and the dividing point J moment;

Determine the time point of the maximum weight loss value;

Determine the time point of the minimum theoretical screw speed based on the time point of the maximum loss-in-weight value;

Determine the theoretical screw speed corresponding to the time point at which the theoretical screw speed is minimum based on the theoretical screw speed straight line in the second half of feeding;

The actual screw speed straight line in the first half of feeding is determined based on the actual screw speed at the moment before feeding and the theoretical screw speed corresponding to the time point at which the theoretical screw speed is minimum.

In this embodiment, the maximum value of the weight loss and the minimum value of the theoretical screw rotation speed are basically relative. Therefore, by determining the moment when the weight loss weight reaches the maximum value, the minimum value of the screw theoretical rotation speed can be determined. Since the minimum value of the theoretical screw speed is also located on the linear regression line of the theoretical screw speed obtained in the aforementioned manner, therefore, determining the theoretical screw speed of the linear regression line at that moment also determines the minimum value of the theoretical screw speed. At the same time, since the actual screw speed at the moment before feeding is determined, the values of the theoretical screw speed at the starting point and end point of the feeding phase are both determined. According to the values of the screw theoretical speed at the starting point and end point of the feeding phase, it can be determined The linear function of the theoretical screw speed in the feeding stage, and then the weight accuracy of the loss-in-weight scale can be calculated based on this linear function and the determined theoretical screw speed.

In one embodiment, the screw cycle dynamic metering accuracy e is calculated by the following formula:

Where {V ₁ , V ₂₁ } is the set of data sequences V ₁ and V ₂₁ , For data sequence/> is a set of , sum is the summation function, τ is the time between the start of feeding and the dividing point J, and T is the cycle time.

In this embodiment, {V ₁ , V ₂₁ } is a set of data sequences V ₁ and V ₂₁ , which is a set formed by the numerical combination of V ₁ and V ₂₁ in the same period range. For data sequence/> The set is composed of the same period range/> Through the above method, the screw periodic dynamic measurement accuracy e can be calculated.

In one embodiment, the dynamic measurement accuracy estimation method further includes:

Obtain multiple continuous periodic dynamic measurement accuracy;

Calculate the dynamic measurement accuracy of the loss-in-weight weighing screw speed data based on multiple consecutive periodic dynamic measurement accuracy.

When calculating the dynamic measurement accuracy of the loss-in-weight weighing screw speed data, the calculation can be performed by averaging the dynamic measurement accuracy of multiple consecutive cycles, or by using the variance method.

In one embodiment, before the step of performing linear regression analysis of screw speed data based on segmented data, the step further includes:

Obtain the stabilization time t1 when the actual screw speed is in the uniform speed stage after the feeding is completed;

Get the feeding time t2;

Get the ratio t1/t2 of t1 and t2;

When t1/t2≤1/4,

The steps for linear regression analysis of screw speed data based on segmented data include:

Perform linear regression analysis on the data sequence V ₂₂ , and estimate the actual screw speed at the breaking point J based on the regression straight line;

The steps to predict the theoretical screw speed during the feeding stage based on the linear regression analysis results include:

According to the actual screw speed at the moment before feeding and the actual screw speed at the dividing point J, a linear regression is performed to estimate the theoretical screw speed during the feeding stage.

The steps to calculate the screw cycle dynamic metering accuracy include:

Calculate the periodic dynamic measurement accuracy e through the following formula:

Where {V ₁ , V ₂₁ } is the set of sequences V ₁ and V ₂₁ , sum is the summation function, τ is the time between the start of feeding and the dividing point J, and T is the cycle time.

In this embodiment, when the ratio between the stable time t1 and the feeding time t2 when the actual screw speed after the feeding is completed is in the uniform stage and is less than or equal to 1/4, it is considered that the stable time after the feeding is completed is much shorter than the feeding time. Feeding time, at this time, you can ignore the stabilization time after the feeding is completed, directly use the dividing point J as the end point of the theoretical screw speed in the feeding stage, and use the actual screw speed just before feeding as the starting point of the theoretical screw speed in the feeding stage, using linear The regression method estimates the screw speed during the feeding stage. It can greatly reduce the calculation workload and simplify the dynamic measurement accuracy estimation method based on the loss-in-weight screw speed data, making the overall calculation process easier to implement and improving calculation efficiency.

Through the above embodiments, the present invention proposes a dynamic metering accuracy estimation method based on loss-in-weight screw speed data. The start time of two consecutive feedings is defined as a cycle, and each cycle is divided into a volume mode stage and a closed-loop control. stage, conduct linear regression analysis on the loss-in-weight weighing screw speed data in the closed-loop control stage, and estimate the theoretical screw speed in the volume mode stage, so that the periodic measurement accuracy can be calculated, and then the dynamic measurement accuracy of continuous production can be estimated.

It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, the singular forms are also intended to include the plural forms unless the context clearly indicates otherwise. Furthermore, it will be understood that when the terms "comprises" and/or "includes" are used in this specification, they indicate There are features, steps, operations, means, components and/or combinations thereof.

It should be noted that the terms "first", "second", etc. in the description and claims of this application and the above-mentioned drawings are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It is to be understood that the data so used are interchangeable under appropriate circumstances so that the embodiments of the application described herein can be practiced in sequences other than those illustrated or described herein.

The above descriptions are only preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and changes. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention shall be included in the protection scope of the present invention.

Claims (10)

1. A dynamic metering precision estimation method based on weightless screw rotating speed data is characterized by comprising the following steps:

extracting and segmenting actual rotation speed data of the screw;

performing linear regression analysis on screw rotation speed data according to the segmented data;

predicting the theoretical rotating speed of the screw rod in the feeding stage according to the linear regression analysis result;

and calculating the dynamic metering precision of the screw period.

2. The method of claim 1, wherein the step of extracting and segmenting screw speed data comprises:

setting the triggering interval of two adjacent feeding as a period;

the actual rotation speed data of the weightless screw rod collected in one period is divided into 2 segments of data sequences V ₁ 、V ₂ The volume mode section and the closed-loop control section are respectively corresponding;

the actual rotation speed V of the screw rod of the closed-loop control section ₂ Divided into 2 segments of data sequence V ₂₁ 、V ₂₂ 。

3. The method for estimating dynamic measurement accuracy according to claim 2, wherein the actual rotational speed V of the screw in the closed-loop control section ₂ Divided into 2 segments of data sequence V ₂₁ 、V ₂₂ The method comprises the following steps:

with closed-loop control of the actual speed sequence V of the section screw ₂ The minimum value of (1) is taken as a demarcation point J, and the actual rotation speed V of the closed-loop control section screw rod is determined ₂ Divided into 2 segments of data sequence V ₂₁ 、V ₂₂ 。

4. A method of estimating accuracy of dynamic measurement according to claim 3, wherein the step of performing linear regression analysis of screw rotation speed data based on the segment data comprises:

for data sequence V ₂₂ Performing linear regression analysis to obtain a regression line of the closed-loop control section;

estimating the theoretical rotating speed of the screw rod between the feeding completion time and the demarcation point J time according to the regression line

5. The method according to claim 4, wherein the step of predicting the theoretical rotational speed of the screw in the feeding stage based on the result of the linear regression analysis comprises:

linear regression is carried out according to the actual rotation speed of the screw rod at the moment before feeding and the estimated actual rotation speed of the screw rod at the moment of finishing feeding, and the theoretical rotation speed of the screw rod at the feeding stage is estimated

6. The method according to claim 5, wherein the step of linearly regressing the actual rotational speed of the screw according to the actual rotational speed of the screw immediately before the feeding and the estimated actual rotational speed of the screw at the feeding completion time comprises:

determining a theoretical rotating speed straight line of the screw in the second half section of the feeding according to a regression straight line from the feeding completion time to the demarcation point J time;

determining a time point when the weightlessness weighing value is maximum;

determining the time point of the moment of minimum theoretical rotating speed of the screw according to the time point of the moment of maximum weightless weighing value; determining the theoretical rotating speed of the screw corresponding to the time point of the minimum moment of the theoretical rotating speed of the screw according to the theoretical rotating speed straight line of the screw in the latter half section of the feeding;

and determining the screw actual rotating speed straight line of the first half section of the feeding according to the screw theoretical rotating speed corresponding to the time point of the minimum moment of the screw actual rotating speed and the screw theoretical rotating speed before feeding.

7. The method for estimating dynamic measurement accuracy according to claim 5, wherein the screw cycle dynamic measurement accuracy e is calculated by the following formula:

wherein { V ₁ ,V ₂₁ Number } isAccording to sequence V ₁ 、V ₂₁ Is a set of (a) and (b),for data sequence->Sum is a sum function, τ is the time between the start of feed and the demarcation point J, and T is the cycle time.

8. The dynamic measurement accuracy estimation method according to claim 1, characterized in that the dynamic measurement accuracy estimation method further comprises:

acquiring a plurality of continuous periodic dynamic metering precision;

and calculating the dynamic metering precision of the rotating speed data of the weightless screw according to the dynamic metering precision of a plurality of continuous periods.

9. The method of claim 2, wherein the volume mode segment is a constant speed segment of the actual rotational speed of the screw, and the closed loop control segment is a variable speed segment of the actual rotational speed of the screw.

10. The method of dynamic measurement accuracy estimation according to claim 2, further comprising, before the step of performing linear regression analysis of screw rotation speed data based on the segment data:

obtaining the stable time t1 of the screw actual rotating speed at a constant speed stage after the material supplementing is completed;

acquiring a feeding time t2;

acquiring the ratio t1/t2 of t1 to t2;

when t1/t2 is less than or equal to 1/4,

the step of carrying out linear regression analysis on the screw rotating speed data according to the segmented data comprises the following steps:

for data sequence V ₂₂ Linear regression analysis is carried out, and the actual rotation speed of the screw at the moment of the demarcation point J is estimated according to a regression line;

the method for predicting the theoretical rotating speed of the screw in the feeding stage according to the linear regression analysis result comprises the following steps:

according to the actual rotation speed of the screw rod at the moment before feeding and the actual rotation speed of the screw rod at the moment of the demarcation point J, linear regression is carried out, and the theoretical rotation speed of the screw rod at the feeding stage is estimated

The step of calculating the dynamic metering precision of the screw period comprises the following steps:

calculating the period dynamic metering precision e by the following formula:

wherein { V ₁ ,V ₂₁ Is sequence V ₁ 、V ₂₁ Sum is a sum function, τ is the time between the start of feed and the demarcation point J, and T is the cycle time.