(76c) Direct Control of Chemical Processes with Multi-Rate Measurements

This paper presents a methodology for direct control of industrial chemical processes with measurements coming to the process control system at different rates. Many measurements are fast and available to the closed-loop controller almost instantaneously. However, some measurements are slow and pose challenges in closing the controller loop along with the fast measurements. Indirect control of fast measurements that help control the slow measurements within certain bounds is one traditional approach. However, indirect control may result in significant variations in the slow measurements that are often key process and economic indicators. On the other hand, direct model-based control of slow measurements can result in tighter and consistent operations that render significant improvements in production rates and process economics. Model-based controller implementations and sustained controller performance needs for an industrial chemical production process are illustrated.