FTC for air path actuators of a diesel engine using VGSTA

Higher Order Sliding Mode (HOSM) based Variable Gain Super Twisting Algorithm (VGSTA) has been used for development of Fault Tolerant Control (FTC) of coupled air management system actuators of a diesel engine. In order to meet stringent emission requirements current diesel engines are equipped with sub-systems, Exhaust Gas Recirculation (EGR) and Variable Geometry Turbo charger (VGT). A nonlinear reduced state control oriented model is employed for working out the coordinated FTC strategy for EGR and VGT actuators. The proposed strategy ensures robustness against minor system faults by varying the controller gains as per the fault bounds given by known functions and consequently reduces the chattering. The effectiveness of the scheme has been established by performing the simulations on a full order diesel engine model.