Integrated multiscale product and process control of polymeric coating curing

In automotive coating manufacturing, control of curing of thin films of wet paint on vehicle panels is always a very challenging operational task. This is especially true when both process efficiency and product quality need to be controlled simultaneously. The challenges in this task are multiple. First, coating quality is not measurable online and its characterization is multiscale in length and time. Second, coating curing is a multistage process where heat and mass transfer and polymerization take place also in multiscale of length and time, most of which are not measurable online either. In this paper, we introduce an integrated multiscale product and process control (IMPPC) scheme that can be used to control effectively the reactive drying process. By resorting to this scheme, a set of advanced methodologies for multiscale modeling, model simplification, and multiscale controller synthesis can be seamlessly integrated to construct a high-performance control system. It is demonstrated that this control system has extraordinary performance on set-point tracking and disturbance rejection. Most importantly, it offers unique opportunities to achieve all-time on-aim control of both coating quality and process performance covering a wide range of time and length scales.