Page 15 - Methods For Monitoring And Diagnosing The Efficiency Of Catalytic Converters A Patent - oriented Survey

xiv Methods for Monitoring and Diagnosing the Eficiency of Catalytic Converters

T : time, period, time delay, temperature
TDC : Top dead center
UEGO : universal exhaust gas oxygen sensor
ULEV : Ultra-Low Emissions Vehicle
V : Voltage, oxygen storage value, velocity
WIPO : World Intellectual Property Organization
WS,W : Laplace transform transfer equation

Greek
Ak : k-1
exis fiiig oxygen conferit actual erigine air I fuel ratio
h or
stoichiometric oxygen carlieill 14.7
E : threshold
z : time delay parameter
@i : correlation fimction, deterioration index
@j : complement fbnction of @i
@xx : auto-correlation function
: cross-correlation function
@xy

S14hscripts - Sirperscripts

1 : value referred to upstream sensor
2 : value referred to downstream sensor
air : air
cat : catalytic converter
f : filtered value
FB : Feedback value
FC : Fuel cut
HL : Highload
in : value of a property entering catalytic converter
L : lean
lean : lean
lim : limit
mean : meanvalue
02 : oxygen
R : rich
real : real
ref : reference value
rich : rich
tm : value calculated by means of a theoretical model
E : threshold value
: average