(613c) Networked Predictive Control of Transport-Reaction Processes Using Event-Triggered Communication

This work focuses on the design of a model predictive control (MPC) system for a class of transport-reaaction processes with low-order dynamics and a limited number of output measurements that are transmitted to the controller over a resource-constrained communication medium. A reduced-order model that captures the dominant process dynamics is initially obtained via model order reduction technioques and used to design a Lyapunov-based output feedback MPC with explicitly characterized stability and performance properties. A finite-dimensional state observer is included in the sensors to generate estimates of the slow states of the infinite-dimensional system which are broadcast over the network to update the states of the reduced-order model used in the MPC controller at each sampling time. Precise conditions that guarantee closed-loop stability under plant-model mismatch are derived and used to devise an event-triggered sensor-controller communication strategy that minimizes the overall network utilization without jeopardizing closed-loop stability. The key idea is to monitor the model estimation error at each sampling time and suspend communication when the prescribed stability bounds obtained based on a forecast of the future evolution of the Lyapunov function are satisfied. During these times the predictive controller continues to rely on the embedded reduced-order model without updating its states to generate the required control action. At times when the model estimation error fails to satisfy the projected stability bound on the evolution of the Lyapunov function, the sensors are prompted to proactively transmit the observer-generated state estimates to update the model states and avert instability. Finally, the design and implementation of the proposed event-triggered networked MPC are illustrated using a representative diffusion-reaction process example.