Design of nonlinear hierarchical controller for intake manifold pressure and boost pressure of turbocharged gasoline engine

Precise tracking control of airpath systems, including intake manifold pressure and boost pressure, is key to ensuring the performance of turbocharged gasoline engines. Aiming at the above objective, this paper proposed a nonlinear hierarchical controller to address the nonlinearity and coupling of airpath systems. First, a control-oriented airpath model is established based on the working principle of a turbocharged gasoline engine. Second, the upper nonlinear controller is deduced in the framework of triple-step control method, whose asymptotic stability is guaranteed by linear system theory. Then, the lower controller contains a throttle opening transformation by MAP (lookup tables) and a nonlinear observer-based controller to track the turbine speed calculated by the upper controller and address the unknown disturbance, thus the actual control inputs consisting of the throttle and wastegate opening position are obtained. Finally, the tracking performance and robustness of the proposed controller are verified by co-simulation using AMESim and Simulink.