# US 8,788,084 B2 · Control method for the meniscus of a continuous casting mold > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 8,788,084 B2 - Document ID: US8788084B2 - Status: Granted - Kind: B2 - Application number: 13/380,686 - Filed: 2010-05-06 - Published: 2012-04-26 - Granted: 2014-07-22 - Earliest claimed: 2009-06-24 - Assignees: Siemens Aktiengesellschaft - Applicants: Martin Niemann; Bernhard Weisshaar - Inventors: Martin Niemann; Bernhard Weisshaar - Web page: https://patentgrep.com/patent/US8788084B2 ## CPC - B22D 11/16: Controlling or regulating processes or operations - B22D 11/181: {responsive to molten metal level or slag level} - B22D: CASTING OF METALS; CASTING OF OTHER SUBSTANCES BY THE SAME PROCESSES OR DEVICES (shaping of plastics or substances in a plastic state B29C; metallurgical processing, selection of substances to be added to metal C21, C22) ## Abstract The inflow of liquid metal into a continuous casting mold is set by a closure device. A measured actual meniscus value is fed to a controller determining a closure device target position on the basis of the actual and a corresponding target value. The measured actual value is fed to a disturbance variable compensator. The target position/corrected target position or a corresponding actual value are further fed to the disturbance variable compensator which determines the disturbance variable compensation value. The disturbance variable compensator has a model of the continuous casting mold for determining an expected value. A number of oscillating compensators determine a frequency disturbance proportion. The sum of the frequency disturbance proportions corresponds to the disturbance variable compensation value. The disturbance variable compensator has a jump determiner, by which it determines the jump compensation value by integrating the difference. ## Claims ### Claim 1 A control method for the meniscus of a continuous casting mold, comprising setting the inflow of liquid metal into the continuous casting mold by means of a closure device and withdrawing the partially solidified metal strand from the continuous casting mold by means of a withdrawal device, feeding a measured actual value of the meniscus to a meniscus controller, which determines a target position for the closure device on the basis of the actual value and a corresponding target value, feeding the measured actual value of the meniscus to a disturbance variable compensator, feeding the target position for the closure device, a target position for the closure device corrected by a disturbance variable compensation value, an actual position of the closure device or an actual position of the closure device corrected by the disturbance variable compensation value to the disturbance variable compensator, determining by the disturbance variable compensator the disturbance variable compensation value on the basis of values fed to it, feeding the target position corrected by the disturbance variable compensation value to the closure device, wherein the disturbance variable compensator comprises a model of the continuous casting mold, by means of which the disturbance variable compensator determines an expected value for the meniscus on the basis of a model input value, wherein the disturbance variable compensator comprises a number of oscillating compensators, by means of which the disturbance variable compensator determines an interference frequency component on the basis of a difference between the actual value and the expected value each relative to a related interference frequency, wherein the sum of the interference frequency components corresponds to the disturbance variable compensation value, wherein the model input value is determined by the relationship i =p′+z′ wherein p′ is the uncorrected target or actual position of the closure device and z′ is a jump compensation value, and wherein the disturbance variable compensator comprises a jump determiner, by means of which the disturbance variable compensator determines the jump compensation value by integrating the difference between actual value and expected value. ### Claim 2 (depends on 1) The control method according to claim 1, wherein the model of the continuous casting mold consists of a series connection of a model integrator with a model delay element, each oscillating compensator consists of a series connection of two oscillating integrators and the jump determiner consists of an individual jump integrator, as the respective input value a value m=Vi+h1e is fed to the model integrator, a value m′=I+h2e is fed to the model delay element, a value s1=h3e−S2 is fed to the front oscillation generator of a respective oscillation compensator, a value s2=h4e+S1 is fed to the back oscillation generator of a respective oscillation compensator and a value s3=h5e is fed to the jump integrator, wherein V is an amplification factor, i is the model input value, e is the difference between the actual value and the expected value, I is the output signal from the model integrator, S1 is the output signal from the respective front oscillation generator, S2 is the output signal from the respective back oscillation generator, h1 and h2 are model adaptation factors, h3 and h4 are specific oscillation adaptation factors for the respective oscillating compensator and h5 is a jump adaptation factor. ### Claim 3 (depends on 2) The control method according to claim 2, wherein the adaptation factors are determined in such a way that the poles of the transmission function determined by the model of the continuous casting mold fulfill the following conditions: for each interference frequency, a pair of conjugate complex poles is formed, whose real parts are smaller than zero and whose imaginary parts are equal to an angular interference frequency defined by the respective interference frequency, three real poles are formed, which are all smaller than zero. ### Claim 4 (depends on 3) The control method according to claim 3, wherein the adaptation factors are determined in such a way that the real parts of the conjugate-complex poles, relative to the respective angular interference frequency, are between −0.3 and −0.1. ### Claim 5 (depends on 3) The control method according to claim 3, wherein the adaptation factors are determined in such a way that the real poles are all smaller than −2.0. ### Claim 6 (depends on 3) The control method according to claim 3, wherein the adaptation factors are determined in such a way that the real poles differ from one another in pairs. ### Claim 7 (depends on 3) The control method according to claim 3, wherein the adaptation factors are determined in such a way that one of the real poles is between −2.5 and −3.5, one is between −3.5 and −4.5 and one is between −4.5 and −5.5. ### Claim 8 (depends on 1) The control method according to claim 1, wherein the number of oscillating compensators is greater than one. ### Claim 9 (depends on 1) The control method according to claim 1, wherein the target position for the closure device or the target position for the closure device corrected by the disturbance variable compensation value is fed to the disturbance variable compensator, but not the actual position of the closure device or the actual position of the closure device corrected by the disturbance variable compensation value. ### Claim 10 (depends on 1) A computer program product comprising a non-transitory computer readable storage medium comprising machine code which when executed directly by a control device for a continuous casting machine causes the control device to control the meniscus of a continuous casting mold of the continuous casting machine according to a control method according to claim 1. ### Claim 11 (depends on 10) The computer program product according to claim 10, wherein the data medium is a component of the control device. ### Claim 12 A control device for a continuous casting machine, wherein the control device is embodied in such a way that, in operation, to set the inflow of liquid metal into the continuous casting mold by means of a closure device and to withdraw the partially solidified metal strand from the continuous casting mold by means of a withdrawal device, to feed a measured actual value of the meniscus to a meniscus controller, which determines a target position for the closure device on the basis of the actual value and a corresponding target value, to feed the measured actual value of the meniscus to a disturbance variable compensator, to feed the target position for the closure device, a target position for the closure device corrected by a disturbance variable compensation value, an actual position of the closure device or an actual position of the closure device corrected by the disturbance variable compensation value to the disturbance variable compensator, to determine by the disturbance variable compensator the disturbance variable compensation value on the basis of values fed to it, to feed the target position corrected by the disturbance variable compensation value to the closure device, wherein the disturbance variable compensator comprises a model of the continuous casting mold, by means of which the disturbance variable compensator determines an expected value for the meniscus on the basis of a model input value, wherein the disturbance variable compensator comprises a number of oscillating compensators, by means of which the disturbance variable compensator determines an interference frequency component on the basis of a difference between the actual value and the expected value each relative to a related interference frequency, wherein the sum of the interference frequency components corresponds to the disturbance variable compensation value, wherein the model input value is determined by the relationship i=p′+z′ wherein p′ is the uncorrected target or actual position of the closure device and z′ is a jump compensation value, and wherein the disturbance variable compensator comprises a jump determiner, by means of which the disturbance variable compensator determines the jump compensation value by integrating the difference between actual value and expected value. ### Claim 13 (depends on 12) A continuous casting machine, wherein it is controlled by a control device according to claim 12. ### Claim 14 (depends on 12) The control device according to claim 12, wherein the model of the continuous casting mold consists of a series connection of a model integrator with a model delay element, each oscillating compensator consists of a series connection of two oscillating integrators and the jump determiner consists of an individual jump integrator, as the respective input value a value m=Vi+h1e is fed to the model integrator, a value m′=I+h2e is fed to the model delay element, a value s1=h3e−S2 is fed to the front oscillation generator of a respective oscillation compensator, a value s2=h4e+S1 is fed to the back oscillation generator of a respective oscillation compensator and a value s3=h5e is fed to the jump integrator, wherein V is an amplification factor, i is the model input value, e is the difference between the actual value and the expected value, I is the output signal from the model integrator, S1 is the output signal from the respective front oscillation generator, S2 is the output signal from the respective back oscillation generator, h1 and h2 are model adaptation factors, h3 and h4 are specific oscillation adaptation factors for the respective oscillating compensator and h5 is a jump adaptation factor. ### Claim 15 (depends on 14) The control device according to claim 14, wherein the adaptation factors are determined in such a way that the poles of the transmission function determined by the model of the continuous casting mold fulfill the following conditions: for each interference frequency, a pair of conjugate complex poles is formed, whose real parts are smaller than zero and whose imaginary parts are equal to an angular interference frequency defined by the respective interference frequency, three real poles are formed, which are all smaller than zero. ### Claim 16 (depends on 15) The control device according to claim 15, wherein the adaptation factors are determined in such a way that the real parts of the conjugate-complex poles, relative to the respective angular interference frequency, are between −0.3 and −0.1. ### Claim 17 (depends on 15) The control device according to claim 15, wherein the adaptation factors are determined in such a way that the real poles are all smaller than −2.0. ### Claim 18 (depends on 15) The control device according to claim 15, wherein the adaptation factors are determined in such a way that the real poles differ from one another in pairs. ### Claim 19 (depends on 15) The control device according to claim 15, wherein the adaptation factors are determined in such a way that one of the real poles is between −2.5 and −3.5, one is between −3.5 and −4.5 and one is between −4.5 and −5.5. ### Claim 20 (depends on 12) The control device according to claim 12, wherein the number of oscillating compensators is greater than one. ### Claim 21 (depends on 12) The control device according to claim 12, wherein the target position for the closure device or the target position for the closure device corrected by the disturbance variable compensation value is fed to the disturbance variable compensator, but not the actual position of the closure device or the actual position of the closure device corrected by the disturbance variable compensation value.