On Stiction Compensation Methods for Practical Nonlinear MPC Implementations

Stiction in actuators is a common issue within the process industry, which may considerably degrade the control performance in practice. In particular, the improved prediction capabilities of model predictive control (MPC) vanish if such actuator imperfections are neglected in actual implementations. In this work, the authors review the more recent approaches for stiction compensation in literature and propose two practical alternatives that are more suitable to use in large-scale nonlinear MPC problems. The proposals are illustrated and tested over a real industrial case study: the fiber humidity control in a medium-density fibreboard dryer.