An ECU 10 for controlling execution of forced regeneration that removes PM deposited on a DPF by increasing a temperature of the DPF in an exhaust gas treatment device of a diesel engine including a DOC disposed in an exhaust passage and the DPF disposed downstream of the DOC includes: a determination unit 102 for determining whether an injection start condition corresponding to a remaining SOF deposition amount on the DOC is satisfied after the forced regeneration starts and after an upstream temperature of the DOC reaches a predetermined temperature; and an injection execution unit 104 for starting late-post injection of fuel to the DOC when the injection start condition is satisfied.

The exhaust purification system of an internal combustion engine includes a filter trapping particulate matter in exhaust gas flowing through an exhaust passage of the internal combustion engine and supporting a three-way catalyst, and a filter regeneration part configured to perform regeneration processing for oxidizing and removing particulate matter deposited on the filter when predetermined conditions are satisfied. The filter regeneration part is configured to increase an NO concentration in exhaust gas flowing into the filter when the predetermined conditions are satisfied compared to when the predetermined conditions are not satisfied.

Methods and systems are provided for protecting an exhaust catalyst from degradation during a DFSO event. Exit from DFSO due to pedal input received from an operator with a jittery foot is averted by filtering the pedal input differently when operating in a DFSO mode as compared to when operating out of the DFSO mode. Exit from DFSO is confirmed after receiving a higher than threshold pedal position input for a sustained period of time, or when an integrated fuel injection amount exceeds a threshold amount.

A system and method for controlling an aftertreatment assembly includes a diesel oxidation catalyst (DOC) device configured to receive an exhaust gas. One or more sensors are configured to obtain respective sensor data relative to the exhaust gas and DOC device. A controller is in communication with the sensors and configured to obtain respective sensor data relative to the exhaust gas. The controller is configured to determine if one or more enabling conditions are met, including reaching a predefined temperature range in the DOC device. A rich event is induced targeting a predetermined range of a lambda value for a predefined maximum time duration. When the rich event has ended, an exotherm index is obtained for an observation window immediately after the rich event. The controller is configured to control operation of the aftertreatment assembly based at least partially on the exotherm index.

A method comprises determining that an aftertreatment system is in a cold-operation mode; initiating a low engine-out NOx (LEON) mode by controlling a component of a vehicle containing the aftertreatment system to decrease an instantaneous engine out NOx (EONOx) amount and to increase exhaust energy relative to a normal operation mode for an engine of the vehicle; receiving information indicative of an operating status of the vehicle during the LEON mode; disengaging the LEON mode; subsequent to disengaging the LEON mode, initiating a thermal management (TM) mode for the aftertreatment system, wherein the TM mode is initiated by controlling a component of the vehicle to increase fueling to the engine for a power level by reducing engine efficiency and directing excess fuel to the aftertreatment system; receiving information indicative of an operating status of the vehicle during the TM mode; and disengaging the TM mode.

When a temperature increasing process is performed, a CPU sets a target temperature of a catalyst to be lower when a coolant temperature is low than when the coolant temperature is high. The CPU decreases an increase coefficient of fuel in the temperature increasing process when a value obtained by subtracting an estimated value of a temperature of the catalyst from the target temperature is equal to or less than a first prescribed value.

A hybrid electric vehicle and a catalyst heating control method are configured to select a point in time at which catalyst heating control is performed and to perform a follow-up measure based on the selected point in time. The catalyst heating control method includes performing mode switching from a first mode in which only a drive motor is used as a driving source to a second mode in which an engine is driven in a state in which a drive shaft and the engine are disconnected from each other to start heating of a catalyst of the engine. When demand torque higher than a maximum output of the drive motor occurs before the catalyst heating is completed, the second mode is maintained until the demand torque is greater than the sum of the maximum output and a predetermined margin.

Systems and methods for controlling a gasoline urea selective catalytic reductant catalyst are described. In one example, an observer is provided that corrects an estimate of an amount of NH.sub.3 that is stored in a SCR. The amount of NH.sub.3 that is stored in the SCR is a basis for generating additional NH.sub.3 or ceasing generation of NH.sub.3.

An ECU 10 includes a valve control unit 101 for throttling a valve opening of at least one of an intake throttle valve or an exhaust throttle valve so that an upstream temperature of a DOC reaches a predetermined temperature; and a deposition condition determination unit 105 for determining whether a deposition condition that a SOF deposition amount on the DOC exceeds a predetermined deposition amount is satisfied. The valve control unit 101 includes a throttle amount decrease control execution unit 102 for executing throttle amount decrease control to decrease a throttle amount of the valve opening when the deposition condition is satisfied to be smaller than when the deposition condition is not satisfied.

Systems and methods for heating an exhaust after treatment device and producing smooth engine torque output are described. In one example, exhaust valve opening time is adjusted to compensate for additional torque that may be generated via combusting rich air-fuel mixtures in cylinders. In addition, intake valve lift may be adjusted to compensate for additional torque that may be generated via combusting rich air-fuel mixtures in cylinders.