A Real-Time Hardware Oriented State Feedback Sliding Mode Actuator Control for Engine Airpath System with Improved Transient Response

Abstract

Authors in this paper have developed a model-based control technique for electromechanical actuator of engine air-path system for real-time application. With the present emission norms, there is a need for faster acting transient controllers. Enhanced numerical methods are needed to solve the gains of the controller for electromechanical actuator which are implicit in nature. In this paper the implicit nonlinear dynamic model of electromechanical actuator is solved using semi-implicit Euler technique portable to a real-time hardware. The simulation shows the model is stable and converging with faster transient response. Further, a sliding surface is designed by solving the state equation with actuator plate angle and angular velocity as state variables. A sliding mode control (SMC) with various sliding surfaces were analyzed. The chattering effects which is inherent to SMC is solved using a sigmoidal function. The developed model is used for predicting and controlling actuator position for airpath models in engine management system (EMS). The model results show accurate tracking of setpoint during transient as well as steady states. Authors also proposes to use this model in case of mild hybrid or full hybrid systems. The switching between the IC engine and hybrid mode can be achieved using a supervisory control which can be easily extended. The SMC applied to such systems increases the transient switching stability and reduces the impulsive load on the drivetrain.