Closed-Loop Combustion Control of Advanced Internal Combustion Engines.

[摘要] Current emphasis on decreasing vehicle fuel consumption and carbon dioxide (CO2) emission from the automotive sector directs many research efforts towards two gasoline engine technologies, namely, the Homogeneous Charge Compression Ignition (HCCI) engines, and the downsized TurboCharged (TC) Spark Ignition Direct Injection (SIDI) engines with variable valve timing (VVT). In the HCCI category, many actuation strategies have been proposed with the more popular being the dual-fuel strategies and the high residual recycling. In this thesis, a heat recycling strategy is considered, specifically, a heated-air inlet HCCI engine with two intake throttles that control the cold and hot air streams. To facilitate the control analysis and development, a physics-based crank-angle resolved and a mean-value models are developed for feedback controller design. We discover that the combustion duration defined as the duration between the crank angle of 10% and 90% fuel burned, provides a universal set point for all speeds and loads for both combustion stability and fuel efficiency. Based on a novel allocation of two actuators, the hot and cold throttles, a feedback controller is designed and simulated to regulate the combustion duration at a desired value during load changes. In the category of the TC SIDI engines, we address the important problem of reducing the calibration complexity when these engines are intended to run on gasoline (E0) and/or a blend of up to 85% ethanol (E85). Typically, there is variability in the optimal VVT and spark values for every blend of gasoline-ethanol. This variability burdens the calibration task for these engines with many degrees of freedom (throttle, VVT, wastegate, fuel injection timing and duration, and spark timing). We first address the transient coupling between throttle and VVT in controlling the air charge. A model-based valve compensator is designed to improve the transient behavior of cylinder charge and torque during tip-ins and tip-outs with the VVT system transitions from set-points. An extremum seeking (ES) controller tuned based on the engine model demonstrates the convergence of both spark timing and VVT to the optimal values to achieve the best fuel efficiency.

[发布机构] University of Michigan

[效力级别] Homogeneous Charge Compression Ignition (HCCI) Engine

[关键词] Closed-loop Combustion Control;Homogeneous Charge Compression Ignition (HCCI) Engine;TurboCharged (TC) Spark Ignition Direct Injection (SIDI) Engines With Variable Valve Timing (VVT);Mechanical Engineering;Engineering;Mechanical Engineering