US 6,240,756 B1 · Path scheduling method and system for rolling mills

Abstract

A tandem rolling mill (FM) has mill stands (Fi; i=1 to 7) to be controlled in conformity with given rolling conditions (j) to execute a given path schedule for a coil (1) to be rolled by rolls (WR) of the mill stands (Fi) to scheduled thicknesses (hi) at exit sides of the mill stands (Fi), with scheduled peripheral speeds (Vi) of the rolls (WR). The mill stands (Fi) are checked for non-conformity with any rolling condition (j), correction amounts (Δγi) are calculated of normalized values (γi*) of rolling forces (Pi*) of non-conforming mill stands (Fi*), as necessary to meet any rolling condition (j*), the normalized values (γi*) are corrected by a maximal one of the correction amounts (Δγi) to provide corrected values as targets (γti*) to be achieved at the non-conforming stands (Fi*), and the given path schedule is re-scheduled to achieve the targets (γti*) by determining re-scheduled thicknesses (hi) of the coil (1) and re-scheduled peripheral speeds (Vi) of the rolls (WR), both independently defining a mass flow of the coil (1) to be constant at the respective mill stands (Fi).

Claims13

Dependent claims

A path scheduling method for a tandem rolling mill having a plurality of mill stands to be controlled in conformity with a plurality of given conditions and a plurality of given constraints thereto to execute a given path schedule for a coil to be rolled by rolls of the plurality of mill stands to scheduled thicknesses at exit sides of the plurality of mill stands, with scheduled peripheral speeds of the rolls, the path scheduling method comprising the steps of:

checking the plurality of mill stands each respectively for non-conformity with any of the plurality of given constraints;
calculating correction amounts of normalized values of rolling forces of non-conforming mill stands, as necessary to meet any of the plurality of given constraints;
correcting the normalized values by a maximal one of the correction amounts to provide corrected values as targets to be achieved at the non-confirming mill stands;
and
re-scheduling the given path schedule to achieve the targets by determining a plurality of re-scheduled thicknesses of the coil and a plurality of re-scheduled peripheral speeds of the rolls, both independently defining a mass flow of the coil to be constant at the plurality of mill stands.

2 more elements

A path scheduling system for a tandem rolling mill having a plurality of mill stands to be controlled in conformity with a plurality of given conditions and a plurality of given constraints thereto to execute a given path schedule for a coil to be rolled by rolls of the plurality of mill stands to scheduled thicknesses at exit sides of the plurality of mill stands, with scheduled peripheral speeds of the rolls, the path scheduling system comprising:

a checker for checking the plurality of mill stands each respectively for non-conformity with any of the plurality of given constraints;
a calculator for calculating correction amounts of normalized values of rolling forces of non-conforming mill stands, as necessary to meet any of the plurality of given constraints, and correcting the normalized values by a maximal one of the correction amounts to provide corrected values as targets to be achieved at the non-conforming mill stands;
and
a scheduler for re-scheduling the given path schedule to achieve the targets by determining a plurality of re-scheduled thicknesses of the coil and a plurality of re-scheduled peripheral speeds of the rolls, both independently defining a mass flow of the coil to be constant at the plurality of mill stands.

1 more element

Dependencies are inferred from the claim text.

Path scheduling method and system for rolling mills

Life of this patent

Path scheduling method and system for rolling mills

Life of this patent

Abstract

Claims13