Real-Time and Robust Estimation of Biodiesel Blends Based on Fuel Consumption and Crankshaft Torsionals

Biodiesel is a renewable alternative fuel which produces lower exhaust emissions compared to its petroleum-based counterpart, diesel. While all of the emissions are less for biodiesel compared to diesel fuel, nitrogen oxides (NO_x) increases. To meet the emissions requirements by engine manufacturers, information about biodiesel fuel must be provided for engine control system to be able to compensate the increase in NO_x emissions caused by using biodiesel. Moreover, biodiesel blend information can be useful to improve performance on the biodiesel fueled engine. Biodiesel blend estimation based on fuel consumption and produced engine torque is investigated in this paper. This strategy is fitted in a robust adaptive estimation structure for achieving a robust estimation. Sensitivity analysis has been done to check the robustness of the estimators against measurement errors.