JPH01255614A - Method for deciding melting process of metal and control method thereof - Google Patents

Abstract

PURPOSE:To save man-hour and to decide suitable melting process by calculating the aimed value for each component of a metal, the aimed temp. for melting and charging wt. for material based on decision rule for melting process and the upper and lower limit values for quality and component standards of the metal. CONSTITUTION:Each data of component standard means (a) and production planning control means (b) stored in a computer 1 for production control and knowledge base (d) having melting process decision rule stored in a computer 2 for expert system are input into an inference engine (e). The inference engine (e) calculates process path, the aimed value for each component to be melted, the aimed temp. for melting and charging wt. for the material based on the rule for deciding the melting process and the upper and lower values for the quality and the component standards of the metal to be melted. These calculated data are inputted in a calculator 3 for process control through communicating means (f), (c) to give the steelmaking equipment 4 the operational command. By this method, the man-hour is saved and the melting plan can be set up under the newest rule, to execute excellent melting.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for determining a metal melting process using knowledge engineering and a method for controlling the same.

[Prior art]

Traditionally, instructions for the melting process of metals, such as steel (hereinafter referred to as melting plans), could only be given by skilled experts (experts), and systemization has yet to be realized due to the difficulty of organizing the knowledge possessed by experts. I haven't. Furthermore, systems constructed with insufficient knowledge cannot be put to practical use because they cannot cope with changes in various conditions that occur one after another after the system is completed. Therefore, in recent years, consideration has been given to creating a melting method using a high-print type expert system based on a production system.

[Problem B to be solved by the invention] As mentioned above, in the past, it took a lot of man-hours for an expert to create a melting plan, and it also required a large number of steel types when there was a change in operating specifications. Since it is impossible to change the melting method, operations will be carried out with an inappropriate melting method, resulting in deterioration of the ferroalloy unit due to component deviations, decreased efficiency of casting work due to low heat, or There were problems such as interruptions and poor quality of slabs.

The present invention was made in view of the above circumstances, and its purpose is to reduce the number of man-hours required to create a melting plan by using the knowledge base of an expert system, and to always keep up to date with the latest specifications and latest rules. A method for determining a metal melting process that enables the creation of a melting plan by eliminating composition deviations, deterioration of ferroalloy basic unit, efficiency reduction or interruption of casting work due to low heat, and defective quality of slabs, and its control method. The aim is to propose the following.

[Means to solve the problem]

The method for determining a metal melting process according to the present invention is a method for determining a process for melting a metal having a predetermined composition standard, in which rules for determining the melting process are prepared in advance as a knowledge base. , to calculate the process path, the target value of each component of the metal to be melted, the target temperature for melting, and the material input amount based on the rules and the upper and lower limit values of the material and component standards of the metal. Features.

Further, the method for controlling the melting process of the present invention consists in controlling the melting process based on the results of the above-mentioned calculations.

[Effect]

In the knowledge base system, its inference engine calculates process paths, etc. using the upper and lower limits of the material and component specifications inputted thereto and a knowledge base prepared in advance.

[Example] Hereinafter, the method of the present invention will be specifically explained based on the drawings. FIG. 1 is a block diagram showing the configuration of an apparatus used to implement the method of the present invention. As shown in the figure, this invention is a production management computer 1. It is implemented by three computers: an expert system computer 2 and a process control computer 3.

The production management computer 1 is a computer that uses procedural knowledge, and has three function implementation means shown in (a) to (C) below.

(a) Means for storing and managing the upper and lower limits of specifications for product components for each material (b) Means for storing and managing manufacturing plans in a steelmaking factory (C) Expert system computer 2 and process control computer 3 In addition, the expert system computer 2 has the following (d)
It has three function realizing means shown in ~(f).

(d), a knowledge base (e) that stores rules for determining the melting process, an inference engine (f) that determines the melting process using the rules stored in this knowledge base, and production management. On the other hand, the process control computer 3 receives information from the production control computer 1, and processes steelmaking equipment (smelting equipment such as a converter, RH, LT, etc., and casting equipment such as a continuous caster). 4, and its operating status is fed back to the production control computer 1.

Next, the method of the present invention will be specifically explained. The expert system computer 2 determines the following four items.

(1), Process path (2), target component (3), target temperature (4) Amount of input of 6 ferroalloys and its brand Each of the above items will be explained below.

(1) Process path determination method For example, in a fiE factory that has steelmaking equipment 4 such as a converter, RH degasser, LT (ladle refining equipment), and continuous caster, the method shown in Fig. 2, B, C. Since there may be three types of process paths as shown in Figure 1, matching of the manufacturing plan management means (b) stored in the production management computer 1 and the knowledge base (d) stored in the expert system computer 2 is necessary. After performing, the inference engine (e) performs inference,
^, B, and C, and manually transmits the determined information to the communication means (C) of the production management computer 1 through the communication means (C) of the expert system computer 2. C) is input to the process control computer 3, and the computer 3 gives an operation command to the steelmaking equipment 4. The continuously cast steel materials produced in process passes A, B, and C are respectively referred to as LT material, RH material, and Ca-treated material.

(2) Method for determining target component values There are three types of target component specifications: those with only the upper limit determined, those with only the lower limit determined, and those with both the upper and lower limits determined, depending on the material and element of the ingot material. In the case of melting, the target component values are set near the upper limit for elements that require cost to lower the component value, and near the lower limit for elements that require cost to increase the component value. From a cost perspective, it is sufficient to set a value close to the upper limit or lower limit as a target value, but in reality, it is necessary to set a value near the upper limit or lower limit as a target value, but in reality, it is necessary to change the steel type in case of variations in the quality of input ferroalloy, variations in yield, controllability, and composition deviations. Target values are set taking into consideration factors such as presence or absence and recovery method. In the method of the present invention, information regarding these components is made into rules and stored in the expert system computer 2 as a knowledge base (d).

A method for determining target component values for the LT material among the continuous casting materials described above will be described below. In order to set the component target value of the LT material as the component value after LT processing, the inference engine (
e) Infers and determines the target component value after LT treatment from the upper limit or lower limit value of the component specifications, and then infers and determines the target component value after converter tapping and the target component value at the end point of the converter. , these decision information are transmitted to the communication means of the expert system computer 2 (
f) to the communication means (C) of the production management computer 2, and the process control calculation n3 is inputted by the communication means (C).
The computer 3 gives an operation command to the steelmaking equipment 4.

Note that the target component values can be inferred and determined for the R11 material and the Ca-treated material using the same concept as for the LT material.

(3) How to determine the target temperature The method for determining the target temperature of the LT material will be described below.

The solidification temperature is determined from the target components after LT treatment, and based on this, the target temperature in the tandye is calculated, and the treatment method in each process is determined after 9 hours, according to the rules regarding temperature drop, after LT treatment, before LT treatment, and in the converter. The inference engine (e) infers and determines each target temperature after tapping and at the end point of the converter, and uses these determination information as (1).

As in the case of (2), the communication means (G) and (C) are used to input to the process control computer 3, and the computer 3 gives an operation command to the steelmaking equipment 4. However, the target temperature at the end point of the converter is
This is calculated after calculating the amount of ferroalloy input described in the next section, taking into account the temperature drop due to ferroalloy input.

Note that the target temperature can also be determined for the R11 material and the Ca-treated material using the same concept as for the LT material.

(4) Determining the brand and amount of ferroalloy 6
(The expert system computer 2 calculates the brand and amount of the ferroalloy to be filled.)

Linear programming is used for this calculation, and an inference engine (e
) is used to find the latest optimal solution according to the situation, and the process control computer 3 gives control commands to each control equipment 4. However, the amount of ferroalloy input calculated here is the value assuming that the target component value at the end point of the converter is achieved as targeted.
In reality, depending on the variations during operation, the above (1) to (3)
The process control computer 3 recalculates based on the determination result of the melting plan. Then, the melting process is controlled based on the results calculated in this way.

[Numerical Example] A method for determining the melting process for LT material will be described below using specific numerical values.

Table 1 shows the upper and lower limit values of the main component specifications among the components of the molten steel used in this example, and the target value after LT treatment, melting target value, and converter end point target value obtained by inference, and Table 2 shows the target value after LT treatment, melting target value, and converter end point target value obtained by inference.
It is a table showing an example of the rule (IP-TIIEN~) of the knowledge base (d) for determining the post-processing target value.

The inference engine (e) infers and determines the target component value after T processing by matching the component standard upper and lower limit values in Table 1 with the rules in Table 2. , the dissolution target value is determined by the inference engine (
e) is inferred, and the converter end point target value is similarly inferred and determined.

However, the C component of the converter end point target value needs to be recalculated by taking into account the C amount in the ferroalloy after determining the amount of ferroalloy to be input.

Further, the target temperature is determined by inference by the inference engine (e) by matching the target temperature determination rules of the manufacturing plan management means (b) and the knowledge base (d).

Table 1 Table 2 The inferred values such as the post-LT treatment target value, melting target value, converter end point target value, etc. shown in Table 1 above are sent to the process control computer 3 along with the target temperature by the production control computer 1 according to the daily manufacturing plan. Set.

In this numerical example, the LT material has been described, but the melting method can be similarly determined for the R11 material and the Ca-treated material.

〔effect〕

As detailed above, in the method of the present invention, experts are required to create an appropriate melting plan by comparing the database and knowledge base using the manufacturing plan management means and component specification management means. In addition, it is possible to always create a melting plan based on the latest specifications and rules, which prevents component deviations, deterioration of the ferroalloy unit consumption, and decreased efficiency or interruption of casting work due to low heat. The present invention has excellent effects such as eliminating defects in the quality of pieces.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of an apparatus used to carry out the method of the present invention;
FIG. 2 is a schematic diagram showing the types of process passes according to the method of the present invention.

Claims (1)

[Claims] 1. In a method for determining a process for melting a metal having a predetermined composition standard, rules for determining the melting process are prepared in advance as a knowledge base, and the rules and the A process path, a target value of each component of a metal to be melted, a target temperature for melting, and a material input amount are calculated based on the material of the metal and the upper and lower limit values of the component specifications. How to determine the melting process. 2. In a method for determining a process for ingotting a metal having a predetermined composition standard, rules for determining the ingot process are prepared in advance as a knowledge base, and the rules and the material and composition specifications of the metal are prepared in advance. Based on the upper and lower limit values, the process path, the target value of each component of the metal to be melted, the target temperature for melting, and the amount of material input are calculated, and the melting process is controlled based on the calculation results. 1. A method for controlling a metal melting process.