Advanced Control on Multi-Mode Combustion Diesel Engines during Transient Operations

燃油经济性和发动机排放是全球交通领域的关键问题。为了有效地处理这些问题，先进的燃烧模式，例如HCCI（均质充量压缩点火）、LTC（低温燃烧）、PCCI（预混合充量压缩点火），通过允许发动机在其峰值效率附近操作而显示出显著的优点。根据美国能源部最近的年度进展报告，使用先进的燃烧模式有可能将重型发动机的燃油效率提高到55%，将轻型车辆的燃油效率提高到35%至50%。 为了实现先进燃烧的广泛采用，必须克服控制中的两个重要障碍。 一个是高级燃烧模式通常伴随着自动点火（即，缺乏明确的燃烧开始指示器），因此需要更全面地考虑和控制缸内条件。另一个挑战在于当燃烧模式由于不同的发动机操作条件而改变时的瞬态控制。对于发动机效率和安全性至关重要的是良好形状的轨迹，其避免了瞬态操作期间不期望的中间燃烧。 本研究将通过以下方式解决这些挑战：1。开发了鲁棒的缸内状态建模和估计方法，该方法可以有效地通过来自进/排气歧管的现成测量来提取缸内状态信息; 2.研究先进的燃烧模式和瞬态动力学; 3.实施一种新的非线性瞬态控制方法，称为非平衡瞬态轨迹成形（NETTS），以解决燃烧模式切换中不期望的瞬态效应。

Fuel economy and engine emissions are critical issues in transportation sector worldwide. To effectively handle these issues, advanced combustion modes, such as HCCI (homogeneous charge compression ignition), LTC (low temperature combustion), PCCI (premixed charge compression ignition), have shown substantial advantages by allowing engines to operate near their peak efficiency. According to the recent annual progress report from the U.S. Department of Energy, using advanced combustion modes has the potential to increase the fuel efficiency of heavy duty engine to as high as 55%, and that of the light-duty vehicle to the range of 35% to 50%. To achieve a broad adoption of advanced combustion, two important barriers in control must be overcome. One is that advanced combustion mode typically occurs with auto-ignition (i.e., lack of an explicit start of combustion indicator), and thus requires a more comprehensive consideration and control of the in-cylinder conditions. The other challenge lies in the control of transients when combustion modes change due to different engine operation conditions. Critical to engine efficiency and safety are well-shaped trajectories which avoid undesired intermediate combustion during the transient operations. This proposed research will focus on solving these challenges by: 1. Developing robust in-cylinder condition modeling and estimation methods, which can effectively extract the in-cylinder condition information by readily available measurements from the intake/exhaust manifolds; 2. Investigating the advanced combustion modes and transient dynamics; 3. Implementing a novel nonlinear transient control methodology, referred to as Non-Equilibrium Transient Trajectory Shaping (NETTS), to tackle undesirable transient effects in combustion mode switchings.