Rolling mill strip thickness controller

Apparatus for controlling the thickness of material produced by a rolling mill stand comprising

• means for producing a first input signal indicative of roll force (F'),
• means for producing a second input signal indicative of rollgap position (S),
• means for producing a third input signal indicative of roll angular position,
• means for producing a fourth input signal indicative of product thickness at a predetermined position downstream relative to the rollgap (h),
• means for deriving from the first, second, third and fourth input signals a first output signal indicative of total roll eccentricity,
• means for coupling the means for producing the first, second, third and fourth input signals to the means for deriving from the first, second, third and fourth input signals an output signal,
• means for deriving a signal indicative of instantaneous product thickness at the rollgap,
• means for compensating the signal indicative of instantaneous product thickness for the total roll eccentricities indicated by the first output signal,
• means for coupling the means for deriving a signal indicative of instantaneous product thickness at the rollgap to the means for compensating the signal indicative of instantaneous product thickness for the total roll eccentricities indicated by the first output signal, and
• means for coupling the means for deriving from the first, second, third and fourth input signals a first output signal indicative of total roll eccentricity to the means for compensating the signal indicative of instantaneous product thickness for the total roll eccentricities indicated by the first output signal.

Apparatus for controlling the thickness of material produced by a rolling mill stand comprising

• means for producing a first input signal indicative of the roll force (F'),
• means for producing a second input signal indicative of rollgap position (S),
• means for producing a third input signal indicative of roll angular position,
• means for producing a fourth input signal indicative of product thickness at a predetermined downstream position relative to the rollgap (h),
• means for deriving from the first, second, third and fourth input signals a first output signal indicative of total roll eccentricities,
• means for coupling the means for producing the first, second, third and fourth input signals to the means for deriving from the first, second, third and fourth input signals a first output signal indicative of total roll eccentricities,
• means for filtering the first output signal to minimize the influence of noise and produce a second output signal representing the predicted, composite roll eccentricity at the rollgap for all rolls whose periods are specified by angular position or speed measurements or roll diameter information,
• means for coupling the means for deriving from the first, second, third and fourth input signals a first output signal indicative of total roll eccentricities to the means for filtering the first output signal,
• means for deriving from the first input signal and second input signal a third output signal indicative of instantaneous product thickness at the rollgap,
• means for coupling the means for producing a first input signal and the means for producing a second input signal to the means for deriving from the first input signal and second input signal a third output signal indicative of instantaneous product thickness at the rollgap,
• means for utilizing the second output signal and third output signal to adjust the rollgap position whereby to control thickness independently of roll eccentricity disturbances, and
• means for coupling the means for filtering the first output signal to minimize the influence of noise and produce a second output signal and the means for deriving from the first input signal and second input signal a third output signal indicative of instantaneous product thickness at the rollgap to the means for utilizing the second output signal and third output signal to adjust the rollgap position.

A rolling mill comprising apparatus for controlling the thickness of material produced thereby, said apparatus including means for producing a first input signal indicative of roll force (F'), means for producing a second input signal indicative of rollgap position (S), means for producing a third input signal indicative of roll angular position, means for producing a fourth input signal indicative of product thickness at a predetermined position downstream relative to the rollgap (h), means for deriving from the first, second, third and fourth input signals a first output signal indicative of total roll eccentricity, means for deriving a signal indicative of instantaneous product thickness at the rollgap, means for compensating the signal indicative of instantaneous product thickness for the total roll eccentricities indicated by the first output signal, means for coupling the first input signal producing means, the second input signal producing means, the third input signal producing means and the fourth input signal producing means to the means for deriving from the first, second, third and fourth input signals a first output signal, means for coupling the means for deriving a signal indicative of instantaneous product thickness at the rollgap to the means for compensating the signal indicative of instantaneous product thickness, and means for coupling the means for deriving from the first, second, third and fourth input signals of first output signal to the means for compensating the signal indicative of instantaneous product thickness.