F2004F367 CHARACTERIZATION AND CONTROL OF THE AIR MANAGEMENT ACTUATORS IN A VARIABLE GEOMETRY TURBOCHARGED DIESEL ENGINE

ABSTRACT- A key issue for compliance with future pollutant emission regulations in variable geometry turbocharged diesel engines is the achievement of a precise control of the air management process, particularly air mass flow ( ) and intake manifold pressure (). P m & a a For a good identification and building of a model-based control (such as Generalized Predictive Control- GPC) of the air management process is fundamental to obtain a good characterization and control of the actuators of the process: exhaust gas recirculation (EGR) valve and variable geometry turbine valve (VGT). In this paper, the characterization of the EGR and VGT non-linearities is discussed (specifically, saturations and hysteresis that vary according to the engine speed). Appropriate position controls are designed for these valves to form a first control layer (internal loop) with the objective of achieving an adjusted main control. The benefits of including this internal loop as part of a cascade control structure, where the main loop regulates Pa and a, are evaluated