Real Time Systems: Parameter Identification for Speed Sensor Wheels

Modern diesel fuel injection system (common rail and pump-nozzle-units) requires the reference of crank angles, engine speed and load to estimate the two parameters: crank angle at the start of fuel injection and amount of fuel to inject for a diesel engine. Measurement of engine speed of a combustion engine is carried out by sensor wheels mounted on the crankshaft. Crank angles can be estimated from the measured engine speed. But geometrical tolerances of a sensor wheel result in systematic errors in the measurement. To get the corrected speed, we have to determine these errors due to geometric tolerances. These geometrical tolerances can be estimated by solving a nonlinear system of equations which is formulated using a suitable physical model of kinetic energy balance of the crankshaft and the measurement of engine speed.