Online calibration of spark advance for combustion phase control of gasoline SI engines

Calibration in combustion phase control is an effective way to get sophisticated engine performance, but is only workable by analyzing offline data or running engine in test mode. When engine is aged or runs at unfamiliar situations, traditional calibration method cannot promise the same performance as before. To improve calibration technique, an online calibration method for combustion phase control is presented, which also works when engine is running in driving operating condition. Based on bilinear interpolation algorithm, online calibration problem is converted to parameters estimation issue, then stochastic gradient descent algorithm is utilized to estimate parameters by iteratively updates. Finally, the proposed strategy is verified on a gasoline spark ignition engine.