Monitoring of exhaust emission limits

摘要

The method involves determining a predicted emission (21) from an engine model (20), and delivering a signal about a measured emission (31) using an exhaust sensor (30). The measured emission is measured from concentration of nitrous oxide or a particle flow of exhaust components. The predicted and measured emissions are compared to form an emission ratio (11). A threshold switch delivers an error signal (15) when the exhaust gas of a vehicle exceeds the emission ratio. The predicted and measured emissions are averaged during a fixed period.