Control of accumulator in a continuous processing line

Abstract

[Abstract]: Continuous processing lines are used in various manufacturing industries including aluminium, paper and steel. Common processes include annealing, pickling, metal coating, hot dip galvanizing, and painting. A standard design feature incorporated by continuous processing line manufacturers is the inclusion of an accumulator at the entry and exits points of the processing section to ensure its continuous operation. Continuous processing of strip and product quality are key performance targets for operating continuous processing lines. Uncontrolled tension transients in the strip will normally result in poor product quality which can be attributed to poor performance from an accumulator control system. Thus, the optimal method of controlling an accumulator in a continuous processing line is a significant and important issue. This dissertation presents an analysis of methods for controlling an accumulator to minimise potential sources of disturbance. The analysis included modelling the accumulator dynamics and simulation with popular industrial control methods. Initially a base case was established using a proportional + integral + derivative controller (PID), which is the current standard for industrial control. The base case was used as the benchmark prior to simulation and analysis of alternative or less conventional industrial controllers. A key emphasis of this dissertation is an association to a real world problem. The project results suggest that the classical PID controller is more suited to this application than the alternatives included in the analysis.