Study of sliding mode observer design to fuel vapor estimation

Fuel vapor emission control would enhance the precise of air to fuel ratio (A/F) control. In this paper, the gasoline flow estimation in vapor purge is fixed as unknown input estimation problem, and an effective observer is proposed to estimate the gasoline flow in vapor purge, which is a sliding mode observer. The convergence of sliding mode observer is involved as well, and the validity of the proposed sliding mode observer is illustrated by the simulation.