Indicated mean effective pressure estimation with applications to adaptive calibration

In recent years, great importance has been placed on the running quality of an internal combustion engine. While running quality affects many different parameters of the engine, it has a significant affect on engine emissions and driver acceptance. Increasing running quality can also improve idle speed control, fuel efficiency and lower engine induced chassis vibrations.; Running quality is typically calculated from variations in the indicated mean effective pressure (IMEP) and therefore the estimation of IMEP is a crucial step in running quality prediction. With this work, the IMEP is estimated from crankshaft acceleration using an optimal estimator. The estimator gains are determined using real world cylinder pressure and IMEP data. The angular locations of the crankshaft acceleration to included in the estimator is discussed and a strategy is developed to reduce estimator order and increase computational efficiency.; Since the estimator gains are determined from real world data, the affects of errors is the estimator gains can be significant as the estimator order increases. These errors can be caused by limited data to calculate the gains or by system non-stationarity. A method of determining the filter order based off the amount of real word data or non-stationary knowledge is used presented.; The optimal estimator is implemented in a current production engine controller. Using the estimator, a strategy is developed to increase running quality by small changes in spark timing. These small changes will be shown to have a significant affect on variations in IMEP and the idle speed controller bandwidth.