Off-Line Optimisation of Complex Automated Production Lines - Applied on a Sheet-Metal Press Line

Abstract

This paper presents a successful off-line optimisation case study of a sheet-metal press line for the automotive industry. The proposed off-line optimisation method results not only in increased production rate but also in obtaining smoother material handling motions. The off-line optimisation method contains two parts. The first part is a parameter study, combining factorial design with production line simulation including emulated control systems and resulting in a simplified performance model based on multiple linear regression. The second part is an optimisation on the simplified performance model using the Nelder Mead simplex method aiming at production optimisation. Due to the complexity in a modern production line, it is not possible to create a useful model representation of the entire control system code/function. Therefore, the proposed optimisation method is based on using production line simulation including emulated control systems with the real IEC 61131-3 control code. Our approach in this work is a parameter variation strategy for optimisation, i.e. adjusting the control system parameters in the same way as the line operators do, and not changing any control strategy.