This dissertation addresses the Diesel engine advanced combustion mode switching transient control and the generalized nonlinear non-equilibrium transient trajectory shaping (NETTS) control problem.
Control-oriented models for air- and fuel-path loops were systematically introduced. Models and observers for in-cylinder conditions (ICCs) at the crank angle of intake valve closing were proposed such that the sophisticated Diesel engine combustion control can be promoted from the intake manifold level to the in-cylinder level. Temperature signal reconstruction and in-cylinder wall temperature estimation methods were developed to satisfy the transient control requirements and the sophisticated control on auto-ignitions. Singular perturbation control method on dual-loop exhaust gas recirculation (EGR) and air-/fuel- paths coordinating control algorithms were devised and applied in the combustion mode transition controls. Simulations by a high-fidelity 1D GT-Power Diesel engine model and experiments on a fully-instrumented medium-duty Diesel engine test bench were conducted to show the effectiveness of the aforementioned models, observers, and control algorithms.
From a general engineering application viewpoint, the advanced combustion mode switching transient control problem can be generalized into a broader scope of nonlinear system control. Based on this motivation, generalized nonlinear system non-equilibrium transient trajectory shaping (NETTS) problems were addressed. By the proposed trajectory shaping control methods, the transient tracking error trajectories of a class of nonlinear systems can be shaped within the pre-defined boundaries, in terms of constant series, partial time-varying three-stage boundaries, symmetric time-varying boundaries, and asymmetric time-varying boundaries, before arriving at the equilibrium state. Besides the shaping of the transient tracking errors, the input constraints for the NETTS were considered.