Pressure and flow based control of a turbocharged diesel engine air-path system equipped with dual-loop EGR and VGT

This paper describes a pressure and flow based control method of diesel engine air-path systems equipped with dual-loop exhaust gas recirculation (EGR) and variable geometry turbine (VGT). For the control of dual-loop EGR systems, fraction states are usually controlled, but how to select the control outputs is still controversial. In this paper, considering availability and reliability of sensors, pressure and mass flow states are selected as control targets instead of fraction states. A robust nonlinear control method, input-output linearization is applied for the states of intake manifold pressure, exhaust manifold pressure, and fresh air mass flow rate in order to satisfy the target emissions. The control performance is verified by simulation based on the valid model of a heavy-duty 6000cc engine air-path.