Abstract:
In a process for presetting the adjusting-member positions of a roll stand upon the rolling of a new coil or for the next pass in each case during cold rolling of bands, adjusting-member positions for the band flatness are used that are based on the corresponding actual data of the first pass of a reference coil, whose reference data results in the best correspondence with the target data of the new coil, or on the actual data of the preceding pass. At the same time, the band thickness can be preset by the specification of a rolling force or adjustment position adapted over a certain time period from the actual data of reference conditions of the roll stand or the rolling mill train.
Abstract:
A method and an apparatus for controlling an object by giving commands to actuators that control the object to perform desired operations, wherein relationships between respective values of parameters of the model for the controlled object and the input/output states of the model are obtained by learning, the obtained relationships are stored in a memory unit as a result of the learning, parameter values of the model are decided by referring to the learning result stored in the memory unit based on the input/output measured values of the controlled object, and commands are obtained based on the decided parameter values and the obtained commands are given to the actuators.
Abstract:
A rolling mill stand which includes roller elements for reducing the thickness of a workpiece which is passed therebetween further includes an adjusting mechanism for adjusting the gap between the roller elements and a sensor for sensing the roll separation force occasioned by passing the workpiece between the roll elements. The stand also includes a sensor for sensing the roller elements position and an automatic gage control device for controlling the gap adjustment mechanism as a function of the roll separation force. Associated with the rolling mill stand is a method of compensating for friction forces within the rolling mill stand occuring as a result of movement of the roller elements so as to improve the accuracy and stability of the automatic gage control.
Abstract:
Proposed herein is a method of controlling the thickness of strip stock being rolled between rolls mounted in the roll stand of a mill. An adjusting force is developed to move the supports of one of the rolls, this force exceeding the rolling force and being directed oppositely thereto. Another force prevents the supports of the rolls from moving towards each other and balances the difference between the adjusting force and the rolling force. The factor of proportionality between the movement of the roll supports and the balancing force is in a definite predetermined ratio with the mill stand stiffness factor. The adjusting force is changed in the course of strip stock deformation to compensate for the roll gap variation in proportion to the rolling force according to the following formula:R=k.sub.2 P,whereR denotes the adjusting force causing the roll supports to move;P denotes the rolling force; andk.sub.2 can be found from the equation:k.sub.2 =(k.sub.1 /k)+1;where k.sub.1 denotes the factor of proportionality between the amount of movement of the roll supports and the balancing force; and k denotes the stiffness factor of the roll mill stand.
Abstract:
A system is first established by connecting apparatus which implements system operations to a digital computer system using an interface system. Machine readable definitions of the system operating configuration are then prepared and fed into the computer system. Included among these definitions are definitions which define designators or names for a number of the system logical variables. These definitions may also include alarm information pertaining to the variables to which they relate and a message which is to be printed out when the related variable enters an alarm state. As each of these definitions is fed into the system, alarm checking of the related variable is immediately commenced. In addition, any system job definition fed into the system at a later time may refer to the variable by designator only, and linkages to the variable are automatically established. A logic director or sequencer may be established by feeding in definitions of jobs which are to be carried out when certain variables enter particular states. Each of these job definitions may refer to one or more variables as triggers. Means within the computer system automatically link each such job definition to the trigger variables in such a manner that when any of the trigger variables changes its state, execution of the defined job immediately commences. The definitions of individual variables and the trigger linkages between variables and executable job definitions may be altered at any time with the same ease that the variable and job definitions are initially fed into the system. All linkage tables within the system are completely rearranged following such an alteration so that no scars remain and so that the maximum amount of space is available within each table for the acceptance of additional linkages.
Abstract:
A system for controlling the thickness of strip in a tandem mill having at least three stands. At a first lower speed the thickness of the strip is corrected in only a first one of the stands of the mill, and at a second higher speed the thickness error is corrected only in a second one of the stands, the second stand being downstream from the first stand. At intermediate speed a thickness error correction takes place in both a first and a second stand.
Abstract:
Gage control method and system for tandem rolling mills of the type wherein final output gage is controlled by comparing actual output gage with desired output gage to develop an error signal for controlling the speed of the last stand and, hence, tension in the strip material being rolled between the last two stands. The invention is characterized in that the roll force exerted on the strip by the last stand is maintained constant for all variations in last stand speed, thereby enabling a greater range of strip gage change via the last stand in the tandem mill.
Abstract:
A computer controlled cold metal rolling mill is described wherein force and power curves stored within a calculated set-up model are adapted in response to sensed on-line rolling conditions to optimize power distribution between stands of the mill. For maximum storage capacity and simplification of the adaptive feedback calculations, the power curves are stored in the set-up model by two numerals representing the slope and base of a graph of power per unit volume flow against elongation as plotted on log log-log scales. Thus, only the slope and base of the actual power curve need be calculated during operation to modify the power curves stored within the set-up model. Adaptation of the force curves within the model is accomplished in association with feedback logic for adjusting the value of the coefficient of friction (assumed for calculation of force) by an amount proportional to the difference between the observed and calculated force. Both fast and slow feedback terms are employed for this purpose with the fast feedback term approaching zero asymptotically as the slow feedback term approaches a coefficient of friction equating the measured and predicted forces. Integral scanning and comparison also are utilized to evaluate the quality of adaptive data before updating the stored curves. Also disclosed is the storage of mill stretch curves as functions of roll force against mill stretch for nominal constant roll force per unit width with a modifier being employed to correct for variations in force per unit width from nominal.
Abstract:
An automatic gage control system for a tandem rolling mill wherein separate control loops are provided for the roll opening controls of each stand. Each control loop responds to a feedback signal based on the predicted gage of the rolled strip leaving the associated stand whereby control errors caused by transport lag are eliminated without causing system instability.
Abstract:
Described is a workpiece gage control system for a hot rolling mill, intended for use as an adjunct to existing gage control systems, which measures the temperature of incoming end of the workpieces and compares this with the temperature of the incoming end of the previous workpiece and the gage of the forward end of the previous workpiece. Assuming that a screwdown correction is required, this comparison results in a control signal which adjusts the screwdown setting of the mill to maintain output gage substantially constant regardless of temperature variations.