This project involved the complete replacement of the Alcoa Davenport Hot Strip MIll, new mill stands and all. Demolition of the existing mill and commissioning of the new mill was completed within a 45 day window. Our state machine based control system architecture played a major role in the success of this project. It provided a robust and reliable means of defining and implementing the mill's various sequential operations and made it easy to make refinements during commissioning.
Each mill stand contained CVC (continuously variable crown) hydraulic cylinders to control the horizontal position of the work rolls, main roll force hydraulic cylinders to control the vertical position and force of the work rolls, roll bending cylinders, and a myriad of electrical and hydraulic devices used for roll change operations. The control system was deployed on a Multibus II platform (one per mill stand) containing four CPUs that performed all mill stand operations. The system consists of the following components:
In addition to providing the system architecture, high level design, and hydraulic control algorithms we worked closely with Alcoa, SMS, and GE during the commissioning phase to identify and solve problems before they manifested. Through our leadership and technical skills we were able to foster a cooperative working relationship between SMS and GE rather than the all too common adversarial relationships that develop in these kinds of situations.