文摘
As one of most effective factors affecting the economy and emissions of internal combustion engines, the combustion phase can maximize performance by tracking its optimum reference. In this study, the combustion phase indicator CA50 is employed for the combustion control of spark-ignited (SI) engines with the application of a cylinder pressure sensor. In order to suppress the influence of cylinder pressure variation on CA50 measurement, a moving average method is used to stabilize CA50 calculation, and based on measured CA50, a linear autoregressive model is obtained by identification, which depicts the relationship between spark advance and combustion phase. Then, a closed-loop controller is synthesized for CA50 regulation, including both feedforward and feedback channels. Finally, the proposed strategy is validated by experiments on an SI engine.