Turbocharged engines often suffer from significant intake manifold pressure response delay due to so-called turbo-lag. Many technologies have been investigated to combat this phenomenon, and combinations of them are often utilized together. The addition of these technologies to already complicated modern engines presents a significant coordinated control challenge due to high system nonlinearity, especially with large operating ranges of engine speed and load. In this paper, a model-based gain-scheduling control strategy is developed, utilizing a constrained
linear parameter-varying (LPV) control strategy, for the Ford 6.7L 8-cylinder diesel engine equipped with a variable geometry turbocharger (VGT), exhaust gas recirculation (EGR), and added eBoost along with a bypass valve. The nonlinear eBoost air charge system is described by an LPV model with two scheduling parameters, engine load and bypass valve position, for this study and LPV controllers are designed for the given operating range of these two parameters. Due to the computational limitation of the production-type control module, the LPV controller is implemented by interpolating LPV control gains solved offline at various grid points of the scheduling parameters to avoid matrix inverse calculation online. The LPV control strategy is validated in both simulation and experimental studies, indicating an up to 84% reduction in engine response time in terms of reaching target intake manifold (boost) pressure following a load step-up, compared with the production configuration (without eBoost and bypass valve) while maintaining the level of NOx emissions. The developed strategy is additionally compared to two previously developed control strategies: a dual-output proportional-integral-derivative (PID) strategy and a model-based linear quadratic tracking with integration (LQTI) strategy.
