LPV Controller Design for Diesel Engine SCR Aftertreatment Systems Based on Quasi-LPV Models

摘要

This letter presents linear parameter-varying (LPV) controller design for the urea-based selective catalytic reduction (SCR) system in diesel engines to reduce nitrogen oxides (NO _X ) and ammonia (NH ₃ ) emissions. Although such LPV SCR controller design has been previously developed, this letter extends it in various ways. The extension includes the usage of NH ₃ slip sensor for feedback LPV control, the adoption of NO _X and NH ₃ measurements downstream of the catalyst as gain-scheduling parameters, the simultaneous design of feedforward and feedback LPV controllers, and a robustness analysis of the LPV controllers. Quasi-LPV SCR models derived from an existing control-oriented nonlinear parameter-varying model are utilized in the LPV controller design. The LPV controller performance is demonstrated based on an SCR simulation utilizing experimentally obtained engine-out NO _X , and exhaust gas temperatures and flow rates. It is shown that the LPV controller provides satisfactory emission performance, as well as robustness against sensor noise and model parameter uncertainty.