A Model Predictive Control Strategy with Integral Action on the Air Path System of a Diesel Engine

Abstract

It is a challenging problem in diesel engines to control throttle, variable geometry turbine(VGT)and exhaust gas recirculation (EGR). A effective method is model predictive control (MPC), which has been successfully applied to typical multi-input multi-output (MIMO) system with fast dynamics, actuator constraints, and strong couplings, such as diesel engines. In MPC controller design, the choice of output variables has a direct impact on the resulting control performance. Through investigating and discussing different selections of outputs, we propose that it is beneficial to select EGR-fraction and boost pressure as output variables while setting the oxygen fuel ratio as a constraint. Besides, equipping an integral action on the EGR ratio can improve the control performance.