Methods of improving SCR performance in heavy duty vehicles may use multiple interdependent control techniques to increase engine exhaust temperatures in a fuel efficient manner. One method combines cylinder deactivation and mechanical loading of an engine by an electrical generator used to input energy into an exhaust stream to manipulate the exhaust temperature through the combined effect of modified air-to-fuel ratio and supplemental energy input. In particular, cylinder deactivation may be used to modify the engine air flowrate and the electric generator may be used to apply mechanical load on the engine to manipulate the engine fuel flow rate to control the engine air-to-fuel ratio and thereby increase exhaust temperatures. The exhaust temperatures may be further increased by using the electrical generator to add the energy generated as input energy to the exhaust stream.

System and methods for detecting NH.sub.3 slip using cross-sensitivity of an NO.sub.x sensor may include accessing a temperature value for a catalyst and determining the temperature value for the catalyst exceeds a predetermined value. If the temperature exceeds the predetermined value, a system-out NO.sub.x measurement signal from the system-out NO.sub.x sensor and an estimated system-out NO.sub.x value are used to calculate a delta value. A flag is set indicative of NH.sub.3 slip for an exhaust system responsive to an average of delta values for a predetermined period of time exceeding a predetermined value. If the temperature does not exceed the predetermined value, then an average of a plurality of system-out NO.sub.x measurement signals can be calculated and a flag is set indicative of NH.sub.3 slip responsive to the calculated average for a predetermined period of time exceeding a predetermined value.

A catalyst warm-up control method for a hybrid vehicle includes a battery supplying electric power to an electric motor, the battery is charged by an engine for electric power generation, and exhaust gas discharged from the engine 1 is treated by a catalyst. By the catalyst warm-up control method, when temperature of the catalyst is lower than required warm-up temperature for activating the catalyst, target revolution speed and target torque of the engine are controlled based on a state of charge of the battery, and, when target revolution speed is lower than lower-limit revolution speed at which the catalyst can be heated to the required warm-up temperature, the target revolution speed is controlled so as to be required warm-up revolution speed that is equal to or higher than the lower-limit revolution speed.

Disclosed are a hybrid electric vehicle, which is capable of controlling engine starting in consideration of entry into a specific area, and method of controlling the same. A method of controlling engine starting of a hybrid vehicle includes determining whether catalyst heating is necessary, determining whether a current location corresponds to a specific area associated with exhaust emissions, determining whether a first mode driving is possible, when it is determined that the current position corresponds to the specific area and the catalyst heating is necessary, and performing the first mode driving when the first mode driving is determined to be possible, or a second mode driving when the first mode driving is determined to be impossible. Here, the first mode driving is performed by using an electric motor, and the second mode driving is performed by using at least an engine.

A method and apparatus for heating an exhaust gas treatment system comprising a catalytic converter and a heat source, the catalytic converter having a first temperature above which the catalytic reaction is of high efficiency, whereby the heat source is controlled so as to generate a heated sub-volume of the catalyst which is in excess of the first temperature and propagates along the length of the catalytic converter such that at any one time the total conversion efficiency of catalytic converter is sufficient to remove a target amount of pollutants from the exhaust gas stream.

A system of controlling an engine includes: an engine including a combustion chamber, an intake valve, an ignition switch, and an exhaust valve; a dual continuously variable valve duration device to adjust an intake duration of the intake valve and an exhaust duration of the exhaust valve; and a controller for adjusting an ignition timing of the ignition switch, the intake duration, and the exhaust duration based on a driving condition of the vehicle. In particular, until the temperature of the exhaust gas reaches a predetermined temperature after the engine starts, the controller sets the ignition timing to an ignition timing within a predetermined ignition timing range, sets the intake duration of the intake valve to an intake duration within a predetermined intake duration range, and increases the exhaust duration of the exhaust valve to a limit exhaust duration according to the set intake duration.

A control device for a hybrid vehicle is provided. When a first drive mode is selected as the drive mode of the hybrid vehicle, a control section shifts the drive mode to a second drive mode when a charge amount of a battery for an electric motor becomes smaller than or equal to a determination charge amount. The first drive mode operates the electric motor while an internal combustion engine is stopped. The second drive mode permits the operation of the internal combustion engine. The control section executes a shifting process when the upper limit system output is lower than or equal to a startup determination output even though the charge amount of the battery is greater than the determination charge amount. The shifting process shifts the drive mode to the second drive mode to start the internal combustion engine.

A hybrid vehicle may include an engine; a turbocharger including a turbine disposed in an exhaust line and a compressor; an electric supercharger disposed in the intake line at an upstream portion of the compressor; an exhaust gas post processing apparatus; a low pressure EGR device which includes a low pressure EGR line, a low pressure EGR cooler and a low pressure EGR valve; an intake bypass line which connects the intake line at a downstream portion of the electric supercharger and the intake line at an upstream portion of the electric supercharger; an intake bypass valve disposed in the intake bypass line; a post processing bypass line which connects the intake line between the electric supercharger and the compressor and the exhaust line between the turbine and the exhaust gas post processing apparatus; and a post processing bypass valve disposed in the post processing bypass line.

The present invention relates to a method for operating a catalyst arrangement of an internal combustion engine and a catalyst arrangement. The catalyst arrangement includes an exhaust gas sensor having a sensor element and a sensor heating device heating the sensor element, and a catalyst having a catalyst heating device heating the catalyst. The method comprises determining a temperature of the catalyst heating device, activating the catalyst heating device for heating the catalyst, when the determined temperature of the catalyst is below a predetermined catalyst operating temperature threshold, and activating the sensor heating device for heating the sensor element, when the temperature of the catalyst exceeds the predetermined catalyst operating temperature threshold.

An exhaust gas treatment system (10) for treating exhaust gases (12) of an internal combustion engine of a motor vehicle has an exhaust gas catalytic converter, a pipe piece (14) connected to an input side of the exhaust gas catalytic converter for feeding in exhaust gases (12) of the internal combustion engine, and a heating line (20) that opens into the pipe piece (14) for feeding heating gas (16) into the pipe piece (14) for heating the exhaust gas catalytic converter to the light-off temperature. The heating gas (16) is fed in as a vortex flow that rotates about a longitudinal axis of the pipe piece (14) to achieve homogeneous thorough mixing with the exhaust gas (12) with rapid heating across an entire cross-section of the exhaust gas catalytic converter.