1. An online correction method for detection data of a particle size analyzer comprises the steps of inputting offline detection data of the fineness of a cement comprehensive sample by using a laboratory data input system, correcting a real-time measurement value of the fineness of the cement comprehensive sample by the particle size analyzer through the offline detection data, and obtaining the offline detection data once in the laboratory data input system at each sampling moment; a plurality of real-time measurement values can be obtained in the granularity analyzer in a time period between every two adjacent sampling moments, and an online detection data is obtained after the average value of the plurality of real-time measurement values and is used as the online detection data of the next sampling moment in the two adjacent sampling moments; the method is characterized in that: the method comprises the following steps:

the method comprises the following steps: acquiring online detection data { x) of the last n sampling moments_iAnd off-line detection data y_iFor each online detection data x_iPreset weight coefficient c_iTo obtain { c_i}; wherein i is more than or equal to 1 and less than or equal to N, and i belongs to N^*；

Step two: constructing a cost functionObtaining linear transformation coefficients a and b capable of minimizing z;

step three: real-time measurement value { x ] in a time period corresponding to the next m sampling moments by using a and b_rCarry out linear transformation to obtain { xnew }_rL R belongs to R, (n +1) delta t is less than or equal to R and less than or equal to (n + m) delta t, the delta t is the time interval of two adjacent sampling moments, xnew_r＝ax_r+ b; by xnew_rCompleting the correction of the real-time measured value of the particle size analyzer;

step four: and repeating the first step, the second step and the third step.

2. The method for on-line calibration of particle size analyzer test data according to claim 1, wherein: before the second step, the correlation coefficient of the online detection data and the offline detection data is calculatedAnd the correlation coefficient is compared with the lower warning limit rho_minLower stop limit ρ_mminComparing to obtain a drift result; in particular, the amount of the solvent to be used,

if the drift result is not 'drift', continuing to run the subsequent steps; if the drift result is the early warning of 'drift', continuing to run the subsequent steps, but simultaneously sending out the early warning; and if the drift result is 'drift', stopping running the subsequent steps.

3. The method for on-line calibration of particle size analyzer test data according to claim 1, wherein: array of weighting coefficients c_i|1≤i≤n，i∈N^*The arithmetic is the row of increasing arithmetic numbers.

4. An on-line calibration system for particle analyzer test data, comprising:

the advanced control system can be used as an operation carrier of an advanced control algorithm and the online correction method and can be communicated with a distributed control system, a database system and a granularity analyzer;

the distributed control system can read and display the rotating speeds of the powder concentrator and the circulating fan, issue a control command and act the powder concentrator and the circulating fan;

the particle size analyzer is used for detecting the real-time specific surface area, fineness and particle distribution of the cement comprehensive sample and supporting the provision of real-time measurement values for external communication;

the database system is used for storing intermediate operation data of the advanced control system, receiving and storing offline detection data from the laboratory data input system;

the laboratory data input system is used for laboratory personnel to input the off-line detection data of the laboratory on the cement comprehensive sample, and comprises the specific surface area, the fineness and the particle distribution of the cement comprehensive sample.

5. A computer device comprising a memory, a processor and a computer program stored on the memory and executable on the processor, characterized in that the processor implements the online correction method according to any of claims 1-3 when executing the computer program.

Background

Many raw materials and finished products in industrial production and scientific research are in the form of powder, and the size and distribution of powder particles often have important influence on product performance, for example, the particle size of a catalyst influences the speed of a chemical reaction, the particle size of a coating influences the surface gloss of a coating, the particle size of a medicament influences the absorption rate and the treatment effect, and the particle size of cement influences water demand, setting time, strength and the like.

A laser particle size analyzer (hereinafter referred to as a particle size analyzer) is a new instrument for measuring the particle size and distribution of powder. The working principle is as follows: the main machine of the particle size analyzer is internally provided with a laser emitter and a laser receiver, and the powder material to be detected is sucked into the main machine of the particle size analyzer by utilizing the negative pressure generated by compressed air. The laser diffracts when passing through the powdery material, forms light spots with different strengths at the receiver end, converts the optical signal of the receiver end into a digital signal and transmits the digital signal to an upper computer, analyzes the size and the distribution condition of the powder granularity through software, and supports external communication to provide a detection result.

The concrete application of the particle size analyzer in production is introduced by taking the automatic control of cement grinding production as an example:

in the grinding production process, a laboratory generally takes a cement comprehensive sample from a production site every other hour or so for laboratory analysis in a cement enterprise, information such as a cement ratio table, fineness, calcium content and sulfur content is obtained, and then an operator in a central control room is informed of the quality information of a current cement finished product. The cement comprehensive sample is a sample obtained by sampling and converging a cement conveying pipeline by a sampler for a small number of times at fixed time intervals in one hour, and can accurately represent the average performance of the cement produced in the hour. After obtaining the comprehensive sample detection index, an operator (hereinafter referred to as an operator) in the central control room adjusts the rotating speed of a fan, the opening of a cold air valve, the rotating speed of a powder concentrator and the like in a DCS (distributed control System) according to own experience to control the specific surface area and fineness index of the cement. There are some contradictions in this traditional manual control production: 1) the frequency of laboratory test is once an hour, the real-time performance is poor, so that the production regulation of the central control room has hysteresis; 2) the labor intensity of the workers in the laboratory is high, the sampling and testing must be carried out continuously every hour, otherwise, the production becomes blind operation, and the product quality is uncontrollable.

In recent years, some automatic control methods for cement grinding production appear, the principle is that a particle size analyzer is used for obtaining information such as a ratio table, fineness, particle size distribution and the like of cement in real time to serve as feedback, then an advanced control algorithm is used for calculating the rotating speed of an output fan, the opening degree of a cold air valve, the rotating speed of a powder concentrator and the like, and the rotating speed is sent to corresponding equipment of DCS action, so that the aim of replacing an operator and automatically adjusting production is fulfilled. The methods greatly improve the automation degree of cement production, enable the production to become fine and controllable and obtain good economic benefits. It can be said that the particle size analyzer is the eye for realizing the automatic control of the cement grinding production, and the accuracy and the reliability of the data of the particle size analyzer are the prerequisites for realizing the automatic control of the production.

However, there are still some problems in detecting the particle size of the powder material by using a particle size analyzer: after the particle size analyzer is used for a long time, the data can generate a drift phenomenon. The 'drift' phenomenon is explained by taking the fineness of cement detected by a particle size analyzer as an example: before using the particle size analyzer, manufacturers of the particle size analyzer and cement enterprises can respectively detect the same comprehensive sample on a production site by using the particle size analyzer and a laboratory to obtain two different fineness values. And dozens of comprehensive samples in the production process are continuously detected, so that two groups of different fineness values can be obtained. Under normal conditions, because different methods are used for detecting samples in the same production process, the two groups of fineness values have a certain corresponding relation, which is generally regarded as a linear relation. It is generally accepted in the industry that the set of fineness detected by a laboratory is the true value of the cement fineness, and the real-time measurement of the particle size analyzer is the reference value. This is in line with the actual situation because the method used by the cement enterprise laboratory to detect the fineness of the cement comprehensive sample is the method specified by the national standard, and the method is determined to be accurate and effective after years of practical examination and becomes the standard method. Therefore, the particle size analyzer manufacturer can calculate the linear transformation coefficient from the fineness of the particle size analyzer to the fineness of the laboratory by taking the fineness value of the laboratory as a target value and taking the original fineness value detected by the particle size analyzer in the same time period as input through methods such as linear regression and the like. And then, when the fineness of the cement is detected by the granularity analyzer, the original fineness is converted by the conversion coefficient, and the converted fineness value is used as a final fineness detection value of the granularity analyzer. This approach is also referred to as an off-line particle sizer detection data correction method.

The drift phenomenon means that the output characteristics of the particle analyzer slowly change after the particle analyzer is used for a long time due to the influence of various factors such as the temperature, the humidity and the air pressure of a production field, the vibration of the particle analyzer, the normal maintenance condition and the like. If the initially calibrated off-line linear transformation coefficient is still used, the difference between the fineness detected by the laboratory and the fineness detected by the particle size analyzer after transformation is increased, and the result of the fineness detected by the particle size analyzer is considered to be invalid, so that the automatic production control fails. After investigating and researching particle size analyzers of multiple brands at home and abroad, the detection results of the particle size analyzers almost have the phenomenon of 'drifting' in different degrees in the application of automatic control of cement production, and the phenomenon becomes a great adverse factor for restricting the automatic control effect of cement grinding production, and needs to be solved urgently.

Disclosure of Invention

In order to solve the technical problems, the invention provides an online correction method, system and device for detection data of a particle size analyzer.

In order to solve the technical problems, the invention adopts the following technical scheme:

an online correction method for detection data of a particle size analyzer comprises the steps of inputting offline detection data of the fineness of a cement comprehensive sample by using a laboratory data input system, correcting a real-time measurement value of the fineness of the cement comprehensive sample by the particle size analyzer through the offline detection data, and obtaining the offline detection data once in the laboratory data input system at each sampling moment; a plurality of real-time measurement values can be obtained in the granularity analyzer in a time period between every two adjacent sampling moments, and an online detection data is obtained after the average value of the plurality of real-time measurement values and is used as the online detection data of the next sampling moment in the two adjacent sampling moments; the method comprises the following steps:

the method comprises the following steps: acquiring online detection data { x) of the last n sampling moments_iAnd off-line detection data y_iFor each online detection data x_iPreset weight coefficient c_iTo obtain { c_i}; wherein i is more than or equal to 1 and less than or equal to N, and i belongs to N^*；

Step two: constructing a cost functionObtaining linear transformation coefficients a and b capable of minimizing z;

step three: real-time measurement in time period corresponding to next m sampling moments by using a and bValue { x_rCarry out linear transformation to obtain { xnew }_rL R belongs to R, (n +1) delta t is less than or equal to R and less than or equal to (n + m) delta t, the delta t is the time interval of two adjacent sampling moments, xnew_r＝ax_r+ b; by xnew_rCompleting the correction of the real-time measured value of the particle size analyzer;

step four: and repeating the first step, the second step and the third step.

Specifically, before the second step, the correlation coefficient of the online detection data and the offline detection data is calculatedAnd the correlation coefficient is compared with the lower warning limit rho_minLower stop limit ρ_mminComparing to obtain a drift result; in particular, the amount of the solvent to be used,

if the drift result is not 'drift', continuing to run the subsequent steps; if the drift result is the early warning of 'drift', continuing to run the subsequent steps, but simultaneously sending out the early warning; and if the drift result is 'drift', stopping running the subsequent steps.

Specifically, the series of weight coefficients { c }_i|1≤i≤N,i∈N^*The arithmetic is the row of increasing arithmetic numbers.

An on-line calibration system for particle analyzer test data, comprising:

the advanced control system can be used as an operation carrier of an advanced control algorithm and the online correction method and can be communicated with a distributed control system, a database system and a granularity analyzer;

the distributed control system can read and display the rotating speeds of the powder concentrator and the circulating fan, issue a control command and act the powder concentrator and the circulating fan;

the particle size analyzer is used for detecting the real-time specific surface area, fineness and particle distribution of the cement comprehensive sample and supporting the provision of real-time measurement values for external communication;

the database system is used for storing intermediate operation data of the advanced control system, receiving and storing offline detection data from the laboratory data input system;

the laboratory data input system is used for laboratory personnel to input the off-line detection data of the laboratory on the cement comprehensive sample, and comprises the specific surface area, the fineness and the particle distribution of the cement comprehensive sample.

A computer device comprising a memory, a processor and a computer program stored on said memory and executable on said processor, said processor implementing said online correction method when executing said computer program.

Compared with the prior art, the invention has the beneficial technical effects that:

the automatic control technology for cement grinding production is widely applied to the cement industry as the core of intelligent manufacturing. Compared with manual control, the automatic production control enables the cement production process to be fine and controllable due to the characteristics of high action frequency, edge clamping optimization and the like, and good quality benefit and economic benefit are obtained. However, due to the influence of many factors such as the temperature, humidity, air pressure of the production site, the vibration of the instrument and the maintenance condition in a flat time, the detection output characteristic of the particle size analyzer, which is the core detection device, on which the automatic control of the cement grinding depends, may slowly change with time. If the traditional off-line data correction method is used, the difference between indexes such as specific surface area and fineness of cement detected and output by a particle size analyzer and a value detected by a laboratory after long-time use is increased, so that the automatic control of cement grinding production becomes uncontrollable or even fails.

According to the online data correction method for the particle size analyzer, disclosed by the invention, the online high-frequency particle size analyzer detection data is corrected by utilizing the offline low-frequency laboratory detection data, so that the accuracy and the reliability of the particle size analyzer detection data are improved, and a good foundation is laid for the automatic control of cement production.

Specifically, the online correction method for the detection data of the particle size analyzer has the following advantages:

1. increasing data accuracy and reliability. By being atCorrelation coefficient rho between detection data of line-calculation particle analyzer and detection data of laboratory_xyWhether the particle size analyzer has a 'drift' phenomenon or not is quantitatively judged, whether the particle size analyzer is abnormal or not can be found at the first time, the reliability and the accuracy of the original data output by the particle size analyzer are ensured, and the dangerous condition that the detection data of the particle size analyzer after failure is continuously taken as the input of the advanced control algorithm is avoided;

2. the response is quick, the lag is small, and the influence on the automatic production control is small. By introducing a weighting factor c₁,c₂,...,c_i,...,c_n(1≤i≤n,c_iNot less than 0), distinguishing the weight of the detection result data at different moments, wherein the closer the detection result data is to the current time, the greater the influence on the online calculation of the linear transformation coefficient is, so that the linear transformation coefficient can be quickly adjusted to be suitable for the current moment, and the adjustment speed is high;

3. and obtaining an optimal correction result under certain conditions. By constructing a cost function, the calculated linear transformation coefficient is optimal under a certain condition, the condition that the deviation of the final output data output by the particle analyzer is large due to improper setting of the linear transformation coefficient is avoided, and the phenomenon of 'drifting' generated after correction data is avoided in principle;

4. the adaptive detection range is wider. The method of offline correction data relies on initial linear transform coefficients calculated from initial offline test results, which have a limited sample range. The invention iteratively updates and constructs the sample data set of the offline detection result, and further iteratively updates the linear transformation coefficient, so that the online updated linear transformation coefficient is always adaptive to the current moment. The range of the constructed offline detection result data set is larger, so that the adaptive detection range is wider;

5. and the labor intensity of laboratory personnel is reduced. The frequency of detecting cement comprehensive samples in laboratories commonly adopted by cement enterprises at present is 1 h/time, and by adopting the particle size analysis detection data online correction method, the goodness of fit between a particle size analyzer and the laboratory data is improved, namely the reliability of detection results of the particle size analyzer is improved. Can utilize the particle size analyzer to detect and replace laboratory personnel to detect for the frequency that the laboratory detected the comprehensive appearance reduces to 2 h/time or even lower, effectively alleviates laboratory personnel intensity of labour.

Drawings

FIG. 1 is a block diagram of an on-line calibration system of the present invention;

FIG. 2 is a schematic diagram of the off-line calibration result of the real-time measurement value of the particle size analyzer of the present invention;

FIG. 3 is a schematic diagram of the on-line calibration result of the real-time measurement value of the particle size analyzer of the present invention.

Detailed Description

Preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

As shown in fig. 1, the online calibration System mainly includes an advanced control System (hereinafter referred to as an advanced control System), a Distributed control System (hereinafter referred to as a DCS System), a granularity analyzer, a database System, and a laboratory data input System. The first control system is an operation carrier of an advanced control algorithm and a granularity analyzer online data correction algorithm, and has the function of communicating with an external DCS system, a database system and a granularity analyzer. In this embodiment, the first Control system communicates with the DCS system and the granularity analyzer by using an OPC (Object Linking and Embedding for Process Control, hereinafter referred to as OPC protocol) communication protocol. The DCS is an original production control system of a cement enterprise, can read and display the real-time running state of bottom layer production equipment, issues a control command to the bottom layer production equipment to adjust production, provides a communication function for the outside, and supports interaction of the production state and equipment state information with the outside. The particle size analyzer is arranged on a cement production line and is used for detecting indexes such as real-time specific surface area, fineness, particle distribution and the like of the produced cement comprehensive sample. The host of the granularity analyzer provides a communication function for the outside, and the first control system can read the detection result through an OPC protocol. The database system is used for storing intermediate operation data of the prior control system, receiving and storing real-time detection data of the cement comprehensive sample input by the laboratory data input system, and comprises information such as specific surface area and fineness. The laboratory data input system can adopt a B/S framework or a C/S framework and is responsible for providing an interface for laboratory personnel to input real-time test results of the cement comprehensive sample being produced at regular intervals, wherein the real-time test results comprise information such as specific surface area, fineness and the like. In this embodiment, it is assumed that laboratory personnel input fineness detection data of the laboratory every 1 hour, and this frequency is also a frequency of detecting production samples generally adopted by cement enterprises at present.

An online correction method for detection data of a particle size analyzer comprises the following specific steps:

s1: an original data set is constructed. Taking the current time n hours before as the reference of 0 time, recording the fineness detection data of n cement comprehensive samples recorded in the 0 th-nth hours of a laboratory data input system as y₁,y₂,…,y_i,…,y_n,(1≤i≤n,i∈N^*) Then the current time is the nth hour.

The first control system reads the real-time measurement value of 0-nth hour from the granularity analyzer by utilizing OPC protocol and records as x₁,x₂,…,x_i,…,x_n,(1≤i≤n,i∈N^*). Because the real-time fineness frequency of the detected output of the particle size analyzer is far higher than the input fineness frequency of a laboratory data input system, x is_iRefers to the average of a plurality of real-time measurements detected by the particle size analyzer during the time period from (i-1) hour to the nth hour of the laboratory. If remember x_rIs a real-time measurement value output by the r time particle size analyzer

In the priority control system, the operator presets x₁,x₂,…,x_i,…,x_n,(1≤i≤n,i∈N^*) Respectively corresponding data weight coefficients of c₁,c₂,...,c_i,...,c_n,(1≤i≤n,i∈N^*,c_iNot less than 0), in general, let c₁Minimum value, representing data x furthest from the current time₁The weight is the smallest. Let c_nMaximum value, representing data x closest to the current time_nThe weight is the largest. Let c₁～c_nThe data in between are linearly uniform, i.e. Obviously, if c is set₁＝c₂Then the weight of each data is equal.

S2: and judging whether the output data of the particle size analyzer has drift. In the priority control system, the correlation coefficient between the x and y two sets of data in step S1 is calculatedComparing with the set value, judging whether the output data of the particle size analyzer has drift, namelyWhere ρ is_mminAnd ρ_minThe lower stop limit and the lower early warning limit are preset for an operator in the early control system. If not, the first control system directly runs the following steps S3-S7; if the early warning of the drift is detected, the first control system then runs the following steps S3-S7, but reminds the operator to closely observe the following correlation coefficient rho_xyThe direction of change of the particle size analyzer is prepared in advance; if the real-time measurement value is not accurate, the operator checks the reason that the real-time measurement value output by the particle size analyzer is not accurate until the problem is solved.

S3: linear transform coefficients a and b are found. Let x be_iAnd y_iThe linear relation exists, and the cost function is constructed in the advanced control system by using the data set in S1A and b are calculated so that z takes a minimum value. Specifically, letObtaining by solution:

s4: the real-time measurements are corrected. Based on the current time (nth hour), within the next m hours (m is the update step length,) And (4) recording the off-line detection data of the produced cement comprehensive sample into a laboratory data input system every 1 hour by laboratory personnel. If y in step S1 is designated_iAnd (i is more than or equal to 1 and less than or equal to n) is ith off-line detection data of the laboratory, and the data input by laboratory personnel in the next m hours is called n +1 to n + m off-line detection data y_i,(n+1≤i≤n+m,i∈N^*)。

On the other hand, in the time period corresponding to the (n +1) th to (n + n) th hours, since the output frequency of the particle size analyzer is high, a plurality of real-time measurement values x are output_r(R belongs to R, n +1 is more than or equal to R and less than or equal to n + m), and the first control system controls the x_rLinear conversion processing is performed to pair x by using a and b obtained in step S3_rMaking linear transformations, i.e. xnew_r＝ax_r+b,(r∈R,n+1≤r≤n+m)。

With xnew_rThe method comprises the steps of using the advanced control algorithm as real-time input of the advanced control algorithm operated in the advanced control system to calculate and output the rotating speed of the powder concentrator and the rotating speed of the circulating fan in real time, transmitting a calculation result to the DCS through OPC communication, and enabling the DCS to operate the powder concentrator and the circulating fan according to the calculation result to complete one-time closed-loop automatic control.

S5: the linear transform coefficients are updated. The first control system reads the off-line detection data recorded from the (m +1) th to the (m + n) th times of the laboratory data input system

Meanwhile, the first control system reads online detection data from the m +1 hour to the m + n hour from the granularity analyzer by utilizing an OPC (optical proximity correction) protocolAndconstructing new data sets together; checking the validity of the new data set in step S2, and calculating a new linear transformation coefficient a in step S3_newAnd b_new。

S6: using the new linear transformation coefficient a obtained in step S5 based on the time of the n + mth hour_newAnd b_newTo correct the real-time measurements output by the particle size analyzer over the next m hours. Similarly to step S4, the laboratory staff enters the off-line test data of the cement composite sample into the laboratory data input system every 1 hour, and records the off-line test data asThe first control system reads a plurality of real-time measured values x output by the particle size analyzer from the particle size analyzer within the time from the nth + m +1 hour to the nth +2m hour_r(R ∈ R, n + m + 1. ltoreq. r.ltoreq.n +2m), a calculated in step S5_newAnd b_newMaking corrections for linear transformations, i.e. xnew_r＝a_newx_r+b_new,(r∈R,n+m+1≤r≤n+2m)。

With xnew_rThe method comprises the steps of using the advanced control algorithm as real-time input of the advanced control algorithm operated in the advanced control system to calculate and output the rotating speed of the powder concentrator and the rotating speed of the circulating fan in real time, transmitting a calculation result to the DCS through OPC communication, and enabling the DCS to operate the powder concentrator and the circulating fan according to the calculation result to complete one-time closed-loop automatic control.

S7: and analogizing in turn, continuously iterating the steps S4-S6, dynamically updating a and b, always using the updated a_newAnd b_newCorrecting the real-time measured value of the detection output of the particle size analyzer for the next m hours, and using the corrected xnew_rAnd the fineness is used as the fineness input of the final advanced control algorithm for automatic production, and the closed-loop automatic control process is carried out until the production is finished.

FIG. 2 is an offline calibration result of a real-time measurement value of a particle analyzer, and FIG. 3 is an online calibration result of a real-time measurement value of a particle analyzer, wherein the original fineness of the particle analyzer is a real-time measurement value, and the detection fineness of a laboratory is offline detection data; it can be seen that the real-time measured value of the particle size analyzer is closer to the detection data of a laboratory after being corrected by adopting the on-line correction method of the invention, and the real fineness of the sample is met.

The online correction method of the invention is used for correcting the detected data such as fineness data, specific surface area and the like, and the corrected data are all considered to be within the protection scope of the invention.

It will be evident to those skilled in the art that the invention is not limited to the details of the foregoing illustrative embodiments, and that the present invention may be embodied in other specific forms without departing from the spirit or essential attributes thereof. The present embodiments are therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein, and any reference signs in the claims are not intended to be construed as limiting the claim concerned.

Furthermore, it should be understood that although the present description refers to embodiments, not every embodiment may contain only a single embodiment, and such description is for clarity only, and those skilled in the art should integrate the description, and the embodiments may be combined as appropriate to form other embodiments understood by those skilled in the art.