Online Machine Learning Modeling and Predictive Control of Nonlinear
Systems With Scheduled Mode Transitions
Abstract
This work develops a model predictive control (MPC) scheme using online
learning of recurrent neural network (RNN) models for nonlinear systems
switched between multiple operating regions following a prescribed
switching schedule. Specifically, an RNN model is initially developed
offline to model process dynamics using the historical operational data
collected in a small region around a certain steady-state. After the
system is switched to another operating region under a Lyapunov-based
MPC with suitable constraints to ensure satisfaction of the prescribed
switching schedule policy, RNN models are updated using real-time
process data to improve closed-loop performance. A generalization error
bound is derived for the updated RNN models using the notion of regret,
and closed-loop stability results are established for the switched
nonlinear system under RNN-based MPC. Finally, a chemical process
example with the operation schedule that requires switching between two
steady-states is used to demonstrate the effectiveness of the proposed
RNN-MPC scheme.