Method and system for generating an eccentricity compensation signal for gauge control of position control of a rolling mill

A system for generating and using an eccentricity compensation signal to compensate for the dynamic eccentricity component F.sub.ECC in the total force F+F.sub.ECC applied between two rotatable backup rolls engaging rotating work rolls in a rolling mill as the work rolls of said mill compress a metal strip passing between said work rolls, wherein F relates to the DC component of said total force, said system comprising:

• (a) means for creating a signal proportional to said total force F+F.sub.ECC ;
• (b) means for reducing said DC component F of said total force signal to produce an intermediate signal generally corresponding in phase and magnitude to said eccentricity component F.sub.ECC ;
• (c) a digital filter of the type operated by first and second input signals in accordance with an adaptive noise cancellation algorithm, wherein said first input signal is a noise correlated signal and said second input is an "error" signal having at least a portion correlated with said first input signal to produce a constructed output signal generally corresponding in magnitude and spectrum to said correlated portion of said second input whereby said constructed output signal attempts to reduce said second input to a minimum;
• (d) means for creating a control signal correlated with rotation of at least one of said backup rolls;
• (e) means for connecting said control signal as said first input signal to said digital filter;
• (f) means for connecting said intermediate signal as said second input to said digital filter;
• and,
• (g) means for adjusting said total force applied between said two backup rolls by said constructed output signal from said digital filter.

A system for adjusting the device for exerting a force against a strip being rolled by a rolling mill having at least one rotating backup roll, said system including:

• (a) means for creating a signal F corresponding to a force (F.sub.O) created by said device and a force (F.sub.ECC) caused by eccentricity of said backup roll;
• (b) means for substantially removing said force (F.sub.O) from said signal F;
• (c) digital means for constructing an analog signal corresponding to said eccentricity signal (F.sub.ECC), said digital means being an adaptive digital filter having first digital input corresponding to said eccentricity force F.sub.ECC, a second input correlated with the rotation of said backup roll and a coefficient adjusting algorithm response to said first input and a preselected convergence factor (.mu.), said correlated signal having an incremented value correlated with with and driven by rotation of said backup roll;
• and,
• (d) means for adjusting said device by subtracting said constructed analog signal from said exerted force.

A system for adjusting the device for exerting a force against a strip being rolled by a rolling mill having an upper rotating backup roll and a lower rotating backup roll, said system including:

• (a) means for creating a signal F corresponding to a force (F.sub.O) created by said device and a force (F.sub.ECC) caused by eccentricity and other variables in phase with rotation of one of said bacjup rolls;
• (b) means for substantially removing said force (F.sub.O) from said signal F;
• (c) digital means for constructing an analog signal corresponding to said eccentricity signal (F.sub.ECC), said digital means being first and second adaptive digital filters each filter having an output, a first digital input corresponding to said eccentricity F.sub.ECC, a second input correlated with the rotation of said one of said backup rolls and a coefficient adjusting algorithm responsive to said first input and a preselected convergence factor (.mu.), said correlated signal having an incremented value correlated with and driven by rotation of one of said backcup rolls, said first filter employing a second input correlated with and driven by said uppper backup roll, said second filter employing a second input correlated with and driven by said lower backup roll;
• (d) means for combining the output of each adaptive filter to provide said constructed signal;
• and,
• (e) means for adjusting said device by subtracting said constructed signal from said exerted force.

A control system for generating an eccentricity compensation signal to compensate for the dynamic eccentricity component F.sub.ECC in the total force F+F.sub.ECC applied between two rotatable backup rolls engaging rotating work rolls in a rolling mill as the work rolls of said mill compress a metal strip passing between said work rolls, wherein F relates to the DC component of said total force, said system comprising;

• means for creating a signal proportional to said total force F+F.sub.ECC ;
• means for reducing said DC component F of said total force signal to produce an intermediate signal generally corresponding in phase and magnitude to said eccentricity component F.sub.ECC ;
• an adaptive digital filter means for digitally reconstructing said eccentricity component F.sub.ECC as a signal at the output of said filter means by development of filter coefficients to reduce eccentricity component F.sub.ECC to a minimum;
• and means for adjusting said total force by said signal at the output of said filter means.

A system for generating and using an eccentricity compensation signal to compensate for the dynamic eccentricity component F.sub.ECC in the total force F+F.sub.ECC applied between two rotatable backup rolls engaging rotating work rolls in a rolling mill as the work rolls of said mill compress a metal strip passing between said work rolls to a preselected thickness, wherein F relates to the DC component of said total force, said method comprising:

• (a) means for creating a signal proportional to said total force F+F.sub.ECC ;
• (b) a digital filter of the type operated by first and second input signals in accordance with an adaptive noise cancellation algorithm, wherein said first input signal is a noise correlated signal and said second input is an "error" signal having at least a portion correlated with said first input signal to produce a constructed output signal generally corresponding in magnitude and spectrum to said correlated portion of said second input whereby said constructed output signal attempts to reduce said second input to a minimum;
• (c) means for creating a control signal correlated with rotation of at least one of said backup rolls;
• (d) means for connecting said control signal as said first input signal to said digital filter;
• (e) means for connecting said intermediate signal as said second input to said digital filter;
• and,
• (f) means for adjusting said device by said constructed output signal to maintain said preselected thickness of said metal strip.