Continuous casting plant and corresponding regulation method

Patent metadata

Field	Value
Publication number	US-12447526-B2
Application number	US-202218702471-A
Country	US
Kind code	B2
Filing date	Oct 18, 2022
Priority date	Oct 19, 2021
Publication date	Oct 21, 2025
Grant date	Oct 21, 2025

Abstract

Plant ( 10 ) for the continuous casting of metal products comprising a mould ( 12 ) in which a metal (L) in the molten state is able to be poured with a determinate flow rate (Q), a regulation device ( 16 ) capable of regulating said flow rate (Q), a control unit ( 18 ) configured to manage at least the movements of said regulation device ( 16 ), and at least one detection device ( 19 ) capable of detecting every punctual variation of the level ( 14 ) of metal (L) in said mould ( 12 ) with respect to a nominal value thereof and generating a corresponding variation signal (SV) and sending it said control unit ( 18 ), which is capable of generating a command signal (RS) for said regulation device ( 16 ) in order to cause a desired variation of the flow rate (Q). The present invention also concerns the regulation method for generating the above command signal (RS).

First claim

The invention claimed is:

1. Plant for continuous casting of metal products comprising a mould in which a metal in a molten state is able to be poured with a determinate flow rate, a regulation device capable of regulating said flow rate, a control unit configured to manage at least movements of said regulation device, and at least one detection device capable of detecting every punctual variation of a level of metal in said mould with respect to a nominal value thereof and generating a corresponding variation signal having a frequency, an amplitude and a phase and sending the corresponding variation signal to said control unit, wherein said control unit comprises a central processing unit and at least one memory unit connected to the central processing unit in which at least one first compensation algorithm is stored, wherein the at least one first compensation algorithm is configured to make said central processing unit, without using any measurement or estimate of a disturbance acting on said plant, selectively generate a command signal for said regulation device starting from said variation signal and taking into account an overall delay between the generation of said variation signal and actual actuation of said regulation device, said command signal having at least a command signal variable amplitude and a command signal variable phase.

2. Regulation method for a plant for continuous casting of metal products, having a mould to contain metal in a molten state, regulation means to regulate a flow rate of said metal and keep a level thereof stable in said mould, and a control unit connected to said regulation means, wherein said method comprises a detection step in which detection means detect a punctual variation of said level with respect to a nominal value, and generate a corresponding variation signal, having a frequency, an amplitude and a phase, which is sent to the control unit, and wherein the method further comprises a control step, in which said control unit, in response to said variation signal and in accordance with at least one first compensation algorithm, selectively generates, without using any measurement or estimate of a disturbance acting on said plant, a command signal for said regulation device starting from said variation signal and taking into account an overall delay between the generation of said variation signal and actual actuation of said regulation device, said command signal having at least a command signal variable amplitude and a command signal variable phase.

3. Method as in claim 2 , wherein said control step comprises a calculation sub-step in which said control unit, before calculating said command signal, processes said variation signal and generates, in an iterative manner and instant by instant, a control signal having a control signal amplitude and a control signal phase, which serves as a basis for generation of said command signal, together with a correction value generated on the basis of said at least one first compensation algorithm which takes into account a mathematical system associated with said overall delay.

4. Method as in claim 3 , wherein said mathematical system is considered in a frequency domain and associates a transfer function having a gain and a phase which takes into account said overall delay, said control signal being an input signal of said mathematical system and said command signal being an output signal from said mathematical system, expressed by RS=A r sen(ωt+φ r )≡A c A s sen(ωt+φ+φ s ).

5. Method as in claim 4 , wherein during said calculation sub-step said control unit uses said at least one first compensation algorithm first to calculate an error function defined by a difference between said variation signal and said command signal and expressed as E=A c A s sen(ωt+φ+φ s )+A d sen(ωt+φ d ), and subsequently a cost function proportional to a square of said error function, wherein said cost function is optimized to find optimal values of amplitude and phase of said control signal.

6. Method as in claim 5 , wherein during said calculation sub-step said cost function is optimized on the basis of optimization algorithms selected from a gradient descent algorithm, or an algorithm based on an estimation of a set of moments of a gradient.

7. Plant for continuous casting of metal products comprising:
a mould in which a metal in a molten state is able to be poured with a determinate flow rate;
a regulation device capable of regulating said flow rate;
a control unit configured to manage movements of said regulation device; and
at least one detection device capable of detecting every punctual variation of a level of metal in said mould with respect to a nominal value thereof and generating a corresponding variation signal having a frequency, an amplitude and a phase and sending the corresponding variation signal to said control unit;
wherein said control unit comprises a central processing unit and at least one memory unit connected to the central processing unit in which at least one first compensation algorithm is stored, and
wherein the control unit is programmed and configured to execute the regulation method of claim 2 .

8. Method as in claim 3 , wherein said at least one first compensation algorithm is configured to also compensate the frequency of said control signal in the event that an initial estimate of the frequency of said variation signal is wrong.

9. Method as in claim 3 , wherein said at least one first compensation algorithm generates said control signal only if said variation signal has a frequency greater than or around 0.2 Hz.

10. Method as in claim 5 , wherein said at least one first compensation algorithm is implemented with a neural network artificial intelligence having an input layer containing information relating to the frequency of said control signal, a hidden layer containing functions of activation of oscillatory phenomenon of said variation signal, that is, sine and cosine, weighted with orthogonal components of said control signal, and an output layer which is a linear combination of said control signal, and wherein a backpropagation algorithm of said error function is applied to said neural network for iterative estimation of the orthogonal components and relating to the control signal.

Assignees

• Danieli Off Mecc
• Danieli Automation Spa

Inventors

• Pezzutto Cristiano
• Conte Riccardo
• Brunetti Gianpiero
• Carboni Andrea

Classifications

• G05D9/12

  characterised by the use of electric means · CPC title

• B22D11/10

  Supplying or treating molten metal (B22D41/00 takes precedence) · CPC title

• B22D11/181 Primary

  responsive to molten metal level or slag level · CPC title

• B22D11/041 Primary

  for vertical casting (B22D11/043, B22D11/049 - B22D11/059 take precedence) · CPC title