Immission Oriented Engine NO
x
Control
2013-01-0346
Pollutant immissions must be kept below some threshold values to
prevent health and environmental damage. At the moment, the problem
is usually met by constant emission limits for each vehicle
independently from specific conditions - in particular, without any
relation to the actual immission situation. This approach offers
the advantage of simplicity, but offers no guarantee that the
immission levels will be kept.
New developments, in particular the expected diffusion of i2v
methods, allows suggesting context specific emission levels so that
the total emission roughly corresponding to the local immissions -
can be limited to the target values. To meet this goal,
emission-oriented control will be needed. This paper proposes a
robust control system which allows tracking a time-varying
NOx profile, based on the sliding mode concept. The
design is based on data-driven models of the air path and of the
NOx production, and is validated experimentally on a
4-cylinder 2.0-liter production engine.
The problem of unfeasible limits is also addressed - e.g., the
case in which the required emission level is too low to be met. The
proposed method can be used also for particulate matter and for
both, of course inside the physically possible region.