Cycle-to-cycle feedback control is employed to achieve optimal combustion phasing while maintaining high levels of exhaust gas recirculation by adjusting the spark advance and the exhaust gas recirculation valve position. The control development is based on a control-oriented model that captures the effects of throttle position, exhaust gas recirculation valve position, and spark timing on the combustion phasing. Under the assumption that in-cylinder pressure information is available, an adaptive extended Kalman filter approach is used to estimate the exhaust gas recirculation rate into the intake manifold based on combustion phasing measurements. The estimation algorithm is adaptive since the cycle-to-cycle combustion variability (output covariance) is not known a priori and changes with operating conditions. A linear quadratic regulator controller is designed to maintain optimal combustion phasing while maximizing exhaust gas recirculation levels during load transients coming from throttle tip-in and tip-out commands from the driver. During throttle tip-outs, however, a combination of a high exhaust gas recirculation rate and an overly advanced spark, product of the dynamic response of the system, generates a sequence of misfire events. In this work, an explicit reference governor is used as an add-on scheme to the closed-loop system in order to avoid the violation of the misfire limit. The reference governor is enhanced with model-free learning which enables it to avoid misfires after a learning phase. Experimental results are reported which illustrate the potential of the proposed control strategy for achieving an optimal combustion process during highly diluted conditions for improving fuel efficiency.

中文翻译：

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在高废气再循环稀释条件下，在火花点火发动机中使用避免失火的循环燃烧控制学习参考调速器

采用循环到循环的反馈控制来实现最佳燃烧定相，同时通过调整火花提前和废气再循环阀位置保持高水平的废气再循环。控制开发基于面向控制的模型，该模型捕捉节气门位置、废气再循环阀位置和点火正时对燃烧相位的影响。在缸内压力信息可用的假设下，自适应扩展卡尔曼滤波器方法用于基于燃烧定相测量估计进入进气歧管的废气再循环率。估计算法是自适应的，因为循环到循环的燃烧可变性（输出协方差）不是先验已知的并且随着操作条件而变化。线性二次调节器控制器旨在保持最佳燃烧相位，同时在来自驾驶员油门踩油门和踩油门指令的负载瞬变期间最大限度地提高废气再循环水平。然而，在油门关闭期间，高废气再循环率和过度提前的火花（系统动态响应的产物）的组合会产生一系列失火事件。在这项工作中，显式参考调速器用作闭环系统的附加方案，以避免违反失火限制。参考调控器通过无模型学习得到增强，使其能够避免在学习阶段后出现失火。