Self-optimising control of an SI-engine using a torque sensor

Control of combustion phasing using a torque sensor is developed for a spark-ignited engine to demonstrate a method to increase its efficiency. Combustion phasing is quantified based on the torque signal using the torque ratio concept for combustion modelling. The combustion phasing is adjusted using the spark advance as control signal. An extremum-seeking controller finds the optimal combustion phasing in each cylinder. The combustion phasing is extracted using an algorithm, which considers the torsional resonances in the crankshaft. The torque-based control system is successfully evaluated on-line using internal EGR changes as combustion disturbances. (c) 2007 Published by Elsevier Ltd.