KR100799708B1 - Operation control system of impact drop compensation volume and its control method - Google Patents

Abstract

In the present invention, the impact drop compensation amount calculation control device for controlling mass flow by setting the impact drop compensation amount at the tip of the rolled steel sheet in hot finishing rolling, and the operation control method of the rolling mill, The purpose of the present invention is to provide an impact control device and an operation control method for the impact drop compensation amount which stabilizes the mass flow of the tip of the rolled steel plate by measuring the torque of the main motor rotating the roll and applying the speed compensation amount of the main motor more accurately. have.

According to the present invention, the impact drop compensation amount calculation control device for stabilizing the mass flow of the end of the rolled steel sheet, a data collection device for checking whether the rolled steel sheet enters the rear end stand with a load cell installed in the rear end stand, and is applied to the front and rear end stands SCC which stores and outputs the set value of the rolling torque and the impact drop compensation amount, a motor torque detection device for detecting the measured rolling torque from the main motor which rotates the work roll of the stand, the actual torque and the set torque of the stand, Using a rolling torque deviation comparison device for comparing the deviations of the difference, a rolling torque weight gain calculating device for setting the rolling torque weighting gain, a torque calculating device for calculating torque using the rolling torque calculation model, and the calculated torque Impact drop compensation amount to calculate impact drop compensation amount and output to roll speed PLC The drop impact compensation amount operation control device comprising a device is provided.

Description

Operation control system of impact drop compensation volume and its control method

1 is a conceptual diagram showing an impact drop compensation amount calculation control device according to an embodiment of the present invention,

FIG. 2 is a flowchart illustrating a calculation control method of the impact drop compensation amount calculation control device illustrated in FIG. 1.

       ♠ Explanation of symbols on the main parts of the drawing ♠

  1, 1 ': working roll 2: rolled steel sheet

  5: Load Cell 7, 7 ': Main Motor

  9: Motor Torque Detection Device

  11: Supervisory Control Computer (SCC)

  10, 10 ': Roll speed setting PLC (Programmable logic control)

  21: data acquisition device 31: rolling torque deviation comparison device

  41: rolling torque weight gain calculator 51: rolling torque calculator

61: impact drop compensation amount calculation device

The present invention is an impact drop compensation amount calculation control device for controlling the rotational speed of the work roll of the stand by calculating the impact drop during the rolling process using a plurality of hot finishing mill (hereinafter referred to as 'stand') and its operation control method In particular, the impact drop compensation amount calculation to stabilize the mass flow of the tip of the rolled steel sheet by detecting the torque of the main motor for rotating the work roll of the stand and applying the speed compensation amount of the main motor more accurately A control device and a method for controlling the operation thereof.

The unbalance of the main motor system when the plate passes through the stand by controlling the rolling speed of the rolling mill against the occurrence of dimensional quality deviation and the rolling sheet unstable factor of the tip of the rolled coil steel sheet, which has the highest demand dissatisfaction in hot rolling. It is essential that the technology to prevent the occurrence of miss roll at the tip, eliminate chronic defects of hot rolled products, and improve the control instability in finishing rolling to obtain the best hot rolled quality. to be.

As a hot rolling controller according to the prior art, there is a looper located between the work rolls of each stand (where the front stand located at the front end is called 'i stand' and the rear stand is called 'i + 1 stand'). The tension of the rolled steel sheet spanned between both stands was controlled by the operation of the looper. This looper consists of a looper roll and a looper arm. In general, the looper measures the looper angle and controls the speed of the main motor which rotates the work roll of the stand to reduce the error of the target angle through the height controller.

In addition, the speed of the main motor of the stand i is calculated by the following equation (1).

Here, λ = SSV _{i, i + 1} + Man _i + Lp _i + ΔV _id , where MRH represents the pattern of the work roll rotational speed as the Master Rheostat, and SSRH represents the stand speed rearstat ( Stand Speed Rheostat) is the ratio of the speed to the thickness ratio between each stand in%, SSV is the successive control of the i and i + 1 stands, Man is the driver manual intervention in the i stand, and LP is the looper in the i stand. Is a compensation signal fed back from, and ΔV _id is the amount of i-stand impact drop compensation.

In general, when the rolled steel sheet enters the i + 1 stand, the mass flow may be broken due to the change in the rotational speed of the work roll.

The impact drop compensation amount is determined by Equation 2 below.

Here, T _R is the rolling torque, C _LVC is the Loose Value compensation constant, ΔL is the rolling plate length variation between the stands, G _LVC is the loose value compensation gain, Δt is the tip of the rolled steel sheet It is the time delay from entering after entering loose value.

In order to determine the impact drop compensation amount in Equation 2, the rolling torque uses a value calculated by predicting the rolling torque in a supervisory control computer (SCC). However, when the rolling torque is somewhat large, it is difficult to accurately predict the torque, so it is impossible to accurately set the impact drop compensation amount.

On the other hand, the technical literature related to the technology for determining the impact drop compensation amount in such hot mapping rolling is as follows.

1) In Japanese Patent Laid-Open No. 07-245976 (Invention Name: Speed Compensator of Rolling Machine), the algorithm is started in synchronization with the rolling load signal generated at the same time as the rolling material enters the rolling roll, and three speed compensation quantities are used here. do. The first speed compensation calculation term is the same as the conventional method, and the second speed compensation calculation term samples every speed difference during the previous rolling when the rolling schedule of the current ash and the previous ash is the same. It extracts every time and outputs it as speed compensation amount (V1). The third speed correction calculation term is converted into a speed correction amount V2 based on the output of the plate thickness detector provided between the stands as the plate thickness correction term and outputs it. The final speed reference value V _REF is determined as shown in Equation 3.

On the other hand, 2) Japanese Patent Laid-Open No. 9-239418 (Invention: Speed Compensation Computing Device of Continuous Rolling Mill) has the same structure as the patent of Japanese Patent Laid-Open Publication No. 07-245976 described above, but the calculation method of the second speed compensation calculation section It is different. That is, in Japanese Laid-Open Patent Publication No. 9-239418, when the rolling schedule of the current ash and the previous ash are the same, the maximum deviation from the speed reference value during the speed recovery time from the entry of the rolled steel sheet of the stand (V _{ACTX , i} ), and use it to find the speed correction coefficient (Kx) of i stand. This value assumes that the speed drop characteristics of each stand are the same, and the i + 1 stand speed correction amount V1 is determined as _{VREF1, i + 1} × Kx.

However, the problems of the two Japanese patents described above are as follows.

1) In the case of Japanese Patent Application Laid-Open No. 07-245976, when the speed compensation amount (V1) is obtained, the previous speed deviation is stored in the storage device for the same rolling schedule, and is output in synchronization with the increase of the rolling load during the current speed compensation. I choose the way. The assumptions made by this algorithm assume that the impact drop characteristics will be the same for the same rolling schedule. However, in reality, the assumption that the previous rolling state and the current rolling state are not completely the same due to the manual intervention of the driver, the temperature characteristics of the rolling material, and other disturbances, the assumption that the same speed drop characteristics are generally not satisfied is disadvantageous. .

2) In the case of Japanese Patent Application Laid-open No. Hei 9-239418, when calculating the speed compensation amount (V1), the speed correction coefficient (Kx) obtained with the maximum speed drop of the i stand is obtained and applied to the i + 1 stand. For the same reason as stated above, it is practically difficult to satisfy the assumption that the two (i, i + 1) stands have the same dynamic characteristics.

The present invention is provided to solve the problems of the prior art as described above, in setting the impact drop compensation amount of the tip of the rolled steel sheet in hot finishing rolling, by measuring the motor torque to more accurately compensate the speed compensation of the main motor It is an object of the present invention to provide an impact drop compensation amount arithmetic control device capable of solving a quality defect by stabilizing a mass flow by applying a tip, and a method for controlling the arithmetic operation.

According to the present invention for achieving the object as described above, in the process of finishing rolling the steel sheet using a plurality of stands, the impact drop compensation amount of the end portion of the rolled steel sheet is set and applied to the main motor mass flow ( An impact drop compensation amount calculation control device for stabilizing mass flow, comprising: a data collection device for checking whether a rolled steel sheet enters a rear stand with a load cell installed in the rear stand, and a rolling torque setting value and impact drop applied to the front and rear stands; A supervisory control computer (SCC) for storing and outputting a set value of the compensation amount, a motor torque detection device for detecting a rolling torque actual value from a main motor rotating the work roll of the stand, an actual torque and a set torque of the stand, Rolling torque deviation comparison device for comparing the deviation of the, and the rolling torque weight gain A rolling torque weight gain calculating device for setting the torque, a torque calculating device for calculating torque using the rolling torque calculating model, and calculating the impact drop compensation amount using the calculated torque and setting the roll speed PLC (Programmable Logic Control) There is provided an impact drop compensation amount calculation control device including an impact drop compensation amount calculation device for outputting to a).

In addition, according to the present invention, the impact drop compensation amount of the end of the rolled steel sheet is set in the process of finishing the steel sheet by using a plurality of stands and applied to the main motor to stabilize the mass flow (Mass Flow) of the end of the rolled steel sheet In the method for calculating a drop compensation amount, the method comprising: determining whether the rolled steel sheet has entered an i + 1 stand, receiving a setting value of a rolling torque setting value and an impact drop compensation amount of the i + 1 stand; Measuring a torque of a main motor driving a work roll of a stand to obtain a rolling torque measurement value, measuring an error degree of the rolling torque measurement value with the rolling torque setting value, and obtaining a rolling torque allowable gain; Rolling torque weight gain is obtained in the case where the torque actual value is smaller than γ and larger than the motor torque setting value. Using the rolling torque weight gain to calculate the rolling torque from the rolling torque calculation model as shown in Equation 2 below, and using the rolling torque calculation value to calculate the impact drop compensation amount in the following Equation 3. And setting the roll speed and outputting it to a programmable logic controller (PLC) to control the rotational speed of the work roll of the stand.

Hereinafter, with reference to the accompanying drawings, a preferred embodiment of the impact drop compensation amount calculation control device and the calculation control method according to the present invention will be described in detail.

1 is a conceptual diagram illustrating an impact drop compensation amount calculation control device according to an embodiment of the present invention, and FIG. 2 is a flowchart illustrating a calculation control method of the impact drop compensation amount calculation control device shown in FIG. 1.

As shown in FIG. 1, the impact drop compensation calculation control device 100 includes a data collection device 21 that recognizes from the load cell 5 installed in the stand whether the rolled steel sheet 2 enters the i + 1 stand. To detect the rolling torque measured value applied to the SCC (Supervisory Control Computer) 11 and the work roll 1 'of the i + 1 stand. A motor torque detection device 9, a rolling torque deviation comparison device 31 for comparing the deviation between the actual torque and the set torque, a rolling torque weight gain calculating device 41 for setting the rolling torque weight gain, Rolling torque calculating device 51 for calculating accurate torque using rolling torque calculation model, and impact drop for calculating accurate impact drop compensation amount and outputting to speed setting programmable logic control (PLC) 10, 10 '. Bo And a volume calculation unit (61).

An operation control method of the impact drop compensation amount operation control device having such a configuration will be described.

As shown in FIG. 1 and FIG. 2, the first step S1 checks the time when the rolled steel sheet 2 enters the i + 1 stand in the data collecting device 21. As such, the reason for confirming the time when the rolled steel sheet 2 enters the i + 1 stand in the data collection device 21 is that the impact drop compensation amount of the i + 1 stand has been obtained since the rolled steel sheet 2 enters the i stand. Since the set value is applied and the rolling torque of the i + 1 stand is detected after the rolled steel sheet 2 enters the i + 1 stand, it is necessary to confirm the time when the rolled steel sheet 2 enters the i + 1 stand.

The second step S2 is a step of reading the _set value of the rolling torque set value T _{R, set} and the impact drop compensation amount ΔV _id of the i + 1 stand from the SCC 11.

And the 3rd step S3 detects the rolling torque actual value T _{R, fbk} of the i + 1 stand from the motor torque detection apparatus 9 installed in the i + 1 stand.

In the next step S4, the rolling torque deviation comparison device 31 determines how much the actual measured values T _{R, fbk of} the rolling torque differ from the _{set values} T _{R, set} of the rolling torque set by the SCC 11. To judge. Here, the difference between the two torques is represented by the variable γ, which is called the rolling torque allowable gain. In the impact drop compensation amount calculation control method according to an embodiment of the present invention, γ is set to about 5% of the rated torque, and the setting equation is as follows, and the number of stands constituting the finishing mill is 7 units in total. Assumed In addition, according to the advancing direction of the rolled steel sheet 2, the identification code of F1-F7 was attached | subjected to each of the 1st thru | or 7th stand.

[Formula 1; setting of γ]

γ is set to about 5% of the rated torque of the rolling motor.

About 300 [Kg · m] from F1 to F4 stands

About 225 [Kg · m] from F5 to F6 stand

F7 stands approximately 120 [Kg · m]

In the fifth step S5, the rolling torque weight gain is set according to the determination result in the fourth step. Then, the rolling torque is calculated from the rolling torque calculation model in the sixth step S6. To this end, the present invention proposes a rolling torque calculation model as shown in Equation 4.

Here, α and β are rolling torque weight gains.

The rolling torque weight gains in Equation 4 are proposed as in Equation 5 below.

In addition, the concept of Equation 5 is that when the difference between the measured value and the set value of the rolling torque is less than γ (S5a), the torque of the rolled steel sheet 2 is not so large that there is no significant effect on the quality of the rolled steel sheet 2, α Is 1, β is set to 0, and the sixth step S6, which is a torque calculation step, is performed. However, when the difference between the measured value and the set value of the rolling torque exceeds γ (S5b), the quality of the rolled steel sheet 2 is affected. In this case, the rolling torque weight gains α and β are set from Equation 5, and the impact drop compensation amount is corrected using the rolling torque calculation model.

As an example, when γ is 500 kg · m, α is (1-500 / (500/7) / 10) = 0.3 (30%) and β is 0.7 (70%). That is, it is an arithmetic instruction to use 30% as a set value of torque and 70% as a measured value, respectively, for calculation of compensation amount.

In the sixth step S6, the rolling torque is accurately calculated from the rolling torque calculation model of Equation 4 using the rolling torque weight gain obtained in the fifth step S5, and the impact of the equation 3 in the seventh step S7. The more accurate impact drop compensation amount is calculated from the drop compensation amount setting formula and output to the work roll rotation speed setting PLC of the i + 1 stand.

As described in detail above, the impact drop compensation amount calculation control device and the calculation control method thereof according to the present invention measure the motor torque and apply the speed compensation amount of the main motor more accurately to stabilize the mass flow at the tip end. There is an advantage to solve the defect.

Although the technical idea of the impact drop compensation amount calculation control apparatus and the operation control method of the present invention has been described above with the accompanying drawings, this is for illustrative purposes only and not for limiting the present invention. . In addition, it is obvious that any person skilled in the art can make various modifications and imitations without departing from the scope of the technical idea of the present invention.

Claims (2)

In the process of finishing the steel sheet by using a plurality of stands, the impact drop compensation amount calculation control device which sets the impact drop compensation amount at the tip of the rolled steel sheet and applies it to the main motor to stabilize the mass flow at the tip of the rolled steel sheet. In A data collection device for checking whether a rolled steel sheet enters a rear end stand with a load cell installed in the rear end stand; SCC (Supervisory Control Computer) for storing and outputting the rolling torque setting value and impact drop compensation amount to be applied to the front and rear stands, A motor torque detection device for detecting a rolling torque actual value from a main motor rotating the work roll of the rear stage stand; Rolling torque deviation comparison device for comparing the deviation between the actual torque and the set torque of the rear end stand, A rolling torque weight gain calculating device for setting a weight gain of the rolling torque; A torque calculating device for calculating torque using a rolling torque calculating model, And an impact drop compensation amount calculating device for calculating an impact drop compensation amount using the calculated torque and outputting the impact drop compensation amount to a roll speed programmable PLC. In the method of controlling the impact drop compensation amount to set the impact drop compensation amount at the tip of the rolled steel sheet in the course of finishing rolling the steel plate using a plurality of stands and apply it to the main motor to stabilize the mass flow of the tip of the rolled steel sheet. In Determining whether the rolled steel sheet has entered the rear end stand (i + 1 stand) of the i th stand; Receiving a setting value of a rolling torque setting value and an impact drop compensation amount of the i + 1 stand; Measuring the torque of the main motor driving the work roll of the i + 1 stand to obtain a rolling torque actual value; Measuring an error degree between the measured rolling torque measured value and the rolling torque setting value, and obtaining a rolling torque allowable gain γ; Setting a rolling torque weight gain for the case where the motor torque measured value is less than or greater than the motor torque set value + γ using Equation 1 below; Calculating rolling torque from a rolling torque calculation model as shown in Equation 2 using the rolling torque weight gain; And setting the impact drop compensation amount by using the rolling torque calculation value and outputting the impact drop compensation amount to a roll speed setting PLC (Programmable Logic Control). [Equation 1]

[Equation 2]

[Equation 3]

Here, T _{R, fbk} is the rolling torque actual value, T _{R, set} is the rolling torque set value, γ is the rolling torque allowable gain, α and β are the rolling torque weight gain, T _R is the rolling torque, C _LVC Is the Loose Value compensation constant, ΔL is the variation in the length of the rolled plate between the stands, G _LVC is the Loose Value Compensation Gain, and Δt is the time from the end of the rolled steel sheet to the time the loose value occurs. , ΔV _id is the impact drop compensation amount.

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