SOFTWARE FUNCTION FOR DETERMINING AIR MASS

The engine speed of a single-cylinder engine is not constant, but exhibits characteristic patterns over the course of a working cycle. An engine speed sensor measures these patterns, which are then evaluated by the engine control unit software using a model-based approach. This analysis establishes certain features for different operating phases of the four-stroke engine. The volume of air that reaches the engine cylinder is calculated from these features. The intake air temperature is calculated using a temperature model. That temperature plus intake air volume are used to calculate the air mass and adjust the amount of fuel to be injected.

The software algorithm is built into the electronic EMS control unit.