Claims:1. A controller (110) to operate late post injection based on
hydrocarbon(HC) load in a vehicle (100), said vehicle (100) comprising
an injector (120), a catalyst (130), a diesel particulate 5 filter (140) and a
plurality of temperature sensors (112, 114),
said controller (110) configured to:
 determine an exhaust mass flow, a temperature T4 and a late
injection quantity;
10  compute a HC mass adsorbed on said catalyst (130) based on said
exhaust mass flow, said temperature T4 and said late injection
quantity,
 determine idle state of said vehicle (100), characterized in that,
said controller (110) adapted to:
 shutoff late post injection when said HC mass adsorbed on
said catalyst (130) equates or exceeds a threshold HC mass
value for said catalyst (130).
2. The controller (110) as claimed in claim 1, wherein said controller (110)
calibrated with predetermined said threshold HC mass value for said
20 catalyst (130).
3. The controller (110) as claimed in claim 1, wherein said temperature T4
measured by temperature sensor (112) upstream of said catalyst (130).
4. The controller (110) as claimed in claim 1, wherein said exhaust mass
flow determined based on input air mass and fuel injected quantity by
25 said injector (120).
5. The controller (110) as claimed in claim 1, wherein idle state of said
vehicle (100) determined based on speed, RPM and accelerator pedal
application of said vehicle (100).
6. A method to operate late post injection based on hydrocarbon(HC) load
in a vehicle (100), said vehicle (100) comprising a controller 5 (110), an
injector (120), a catalyst (130), a diesel particulate filter (140) and a
plurality of temperature sensors (112, 114),
said method comprising the step of:
 determining, by said controller (110), an exhaust mass flow, a
10 temperature T4 and a late injection quantity,
 computing, by said controller (110), a HC mass adsorbed on said
catalyst (130) based on said exhaust mass flow, said temperature
T4 and said late injection quantity,
 determining, by said controller (110), idle state of said vehicle (100),
characterized in that,
 shutting off late post injection, by said controller (110), when
said HC mass adsorbed on said catalyst (130) equates or
exceeds a threshold HC mass value for said catalyst (130).
7. The method as claimed in claim 6, wherein said controller (110)
20 calibrated with predetermined said threshold HC mass value for said
catalyst (130).
8. The method as claimed in claim 6, wherein said temperature T4
measured by temperature sensor (112) upstream of said catalyst (130).
9. The method as claimed in claim 6, wherein said exhaust mass flow
25 determined based on input air mass and fuel injected quantity by said
injector (120).
10. The method as claimed in claim 6, wherein idle state of said vehicle
(100) determined based on speed, RPM and accelerator pedal
application of said vehicle (100). , Description:A controller (110) and method to operate late post injection based on
hydrocarbon (HC) load in catalyst. The controller (110) is configured to
determine an exhaust mass flow, a temperature T4 and a late injection
quantity, compute a HC mass adsorbed on the catalyst 5 (130) based on
determined the exhaust mass flow, the temperature T4 and the late injection
quantity, determine idle state of the vehicle (100), characterized in that, the
controller (110) adapted to shutoff late post injection when the HC mass
adsorbed on the catalyst (130) equates or exceeds a threshold HC mass value
10 for the catalyst (130).