Combustion control - variable valve timing for internal combustion engines

目的：内燃（IC）发动机几乎用于所有的车辆应用中，2005年全球估计有8亿辆车辆。我的研究目标之一是提高火花点火内燃机的热效率，减少有害排放，减少温室气体，改善空气质量。均质充量压缩点火（HCCI）：可以降低燃料消耗和一些排放污染物。HCCI具有类似柴油的燃料效率，具有低NOx和低颗粒排放的潜力。在HCCI燃烧中，均匀的空气-燃料混合物在没有火花的情况下自动点火。HCCI具有类似于火花点火发动机的预混合充气，但是点火由类似于柴油发动机的化学动力学触发。我的研究的目标是通过产生独特的实验数据，用于热动力学模拟模型，增加对HCCI燃烧的基本理解，并开发可用于开发控制HCCI燃烧策略的计算模型。本文对单缸火花点火内燃机HCCI可变配气相位进行了热力学分析和试验研究。电磁阀控制：控制内燃机进排气门正时的电磁阀执行器使得研究新的热力学循环成为可能。完全灵活的气门正时是满足HCCI燃烧精确缸内混合要求的一种方式。电磁螺线管阀是获得可变气门正时并允许针对每个燃烧事件控制每个气缸充气的实用方式，但需要反馈运动控制以实现发动机磨损和噪声要求所需的低气门落座速度。为了满足严格的气门着陆速度要求，非线性末端控制将与自适应控制方法相结合。

Objectives: Internal Combustion (IC) engines are used in practically all vehicle applications with an estimated 800 million vehicles worldwide in 2005. One goal of my research is to improve the thermal efficiency and reduce harmful emissions of spark ignition IC engines, reducing greenhouse gases and improving air quality. Homogeneous Charge Compression Ignition(HCCI): can reduce both fuel consumption and some exhaust pollutants. HCCI holds the potential for Diesel like fuel efficiency with low NOx and low particulate emissions. In HCCI combustion a homogeneous air-fuel mixture auto-ignites without a spark. HCCI has a premixed charge like a spark-ignition engine but the ignition is triggered by the chemical kinetics similar to a diesel engine. The goals of my research are to increase the fundamental understanding of HCCI combustion by generating unique experimental data useful for themokinetic simulation models, and to develop computational tractable models that can be used to develop strategies to control HCCI combustion. Thermodynamic analysis and experimental investigation of variable valve timing on a single cylinder spark ignition internal combustion engine running HCCI will be performed. Solenoid Valve Control: Solenoid valve actuators controlling the intake and exhaust valve timing in IC engines make it possible to investigate novel thermodynamic cycles. Completely flexible valve timing is one way to meet the precise in-cylinder mixture requirements for HCCI combustion. Electromagnetic solenoid valves are a practical way to obtain variable valve timing and allow for each cylinder charge to be controlled for each combustion event but require feedback motion control to achieve the low valve seating velocity needed for engine wear and noise requirements. To meet stringent valve landing speed requirements, non-linear end control will be combined with adaptive control methods.