Supervisory control of rolling mills : the optimisation of soaking pit schedules

The work presented in this thesis is the result of research that aims to enhance the supervisory (level II) control system used at Alcoa Europe FRP and supplied by VAI UK. There are opportunities for improvement in three main areas: improved product shape, especially at low gauges fault diagnosis of product quality, to improve yield optimisation of soaking pits/rolling mill process, to increase throughput and improve efficient use of plant resources. The first part of this thesis focuses on the Expert System developed to augment the existing system for improved supervisory control. The Expert System focuses on utilising human knowledge, whilst the existing system provides the infrastructure for the overall system. The second part of the thesis explains the scheduling system developed to manage the operations of the soaking pits upstream of the rolling mill in order to gain maximum throughput from the overall process and to use the plant resources efficiently.