A method for regulation of an internal combustion engine with an SCR catalytic converter in which the operating point of the engine is predefined by an engine control unit and the operating point of the catalytic converter is predefined by an SCR control unit. An overall system quality measure is calculated by an optimizer in accordance with fed back values of the engine control unit and fed back values of the SCR control unit, by changing the default values for the engine control unit and the SCR control unit, the optimizer minimizes the overall system quality measure for a prediction horizon regarding operating costs. On the basis of the minimized overall system quality measure the optimizer sets the default values for the engine control unit and the default values for the SCR control unit as decisive for setting the operating point of the engine and the catalytic converter.

A vehicle includes a battery and a CO.sub.2 recovery device using electric power of the battery to recover CO.sub.2 contained in inflowing gas. A control device mounted in the vehicle controls the CO.sub.2 recovery device. The control device permits operation of the CO.sub.2 recovery device in the case where a high efficiency recovery condition, at which it is predicted that the efficiency of recovery of CO.sub.2, showing a ratio of the amount of recovery of CO.sub.2 in the CO.sub.2 recovery device with respect to the electric power consumed by the battery, will become equal to or greater than a preset predetermined efficiency, is satisfied, and prohibits operation of the CO.sub.2 recovery device in the case where the high efficiency recovery condition is not satisfied.

An aftertreatment system for a diesel engine may include a diesel particulate filter configured for placement in fluid communication with the diesel engine to receive an exhaust flow. The system may also include a selective catalytic reduction system configured for arrangement downstream of the diesel particulate filter and a NO.sub.x sensor configured to measure a NO.sub.x concentration in the exhaust flow entering the selective catalytic reduction system. The system may also include a controller configured to estimate a ratio of NO.sub.2 to NO.sub.x downstream of the diesel particulate filter and based on a factor affecting the generation of NO.sub.2 upstream of the selective catalytic reduction system. The controller may also be configured to adjust the measured NO.sub.x concentration based on the ratio to provide an estimated actual NO.sub.x concentration and dose diesel exhaust fuel into the exhaust flow based on the estimated actual NO.sub.x concentration.

A control system for a vehicle, the control system having one or more controllers, the control system being arranged to: determine a likelihood of a NOx adsorber trap of a vehicle requiring purging; determine an efficiency of purging the NOx adsorber trap; determine an operating efficiency of a selective catalyst reduction system of the vehicle; determine a schedule for purging of the NOx adsorber trap of the vehicle in dependence on the likelihood of the NOx adsorber trap requiring purging, the efficiency of purging the NOx adsorber trap, and the operating efficiency of the selective catalyst reduction system; and control purging of the NOx adsorber trap according to the schedule.

The present disclosure describes methods for evaluating NOx conversion efficiency of a close coupled SCR unit of an EAS including the close coupled SCR unit and a downstream SCR unit. The determined NOx conversion efficiency of the close coupled SCR unit is used to diagnose the close coupled SCR unit and or EAS and to control operation parameters of the EAS and/or internal combustion engine operably connected to the EAS.

The present disclosure describes methods for evaluating quality of DEF dosed to an EAS including a close coupled SCR unit a downstream SCR unit. A NOx conversion efficiency of the close coupled SCR unit and a NOx conversion efficiency of the downstream SCR unit are used to evaluate quality of DEF. In some embodiments, the NOx conversion efficiency of close coupled SCR unit is used to evaluate quality of DEF. Operation of an EAS using the results of the evaluation of quality of DEF are described.

A method for controlling an exhaust after-treatment system based on NO.sub.2 medium adjustment includes the following steps: creating a diesel oxidation catalyst (DOC) reaction map, a diesel particulate filter (DPF) reaction map, and a selective catalytic reduction (SCR) reaction map; obtaining an SCR reaction temperature, desired SCR reaction efficiency, and obtaining NO.sub.2 demand according to the SCR reaction map; obtaining a DPF reaction temperature and differential pressure, and obtaining NO.sub.2 consumption from the DPF reaction map; obtaining NO.sub.2 production, and calculating NO.sub.2 input for SCR; if the NO.sub.2 input is not equal to the NO.sub.2 demand, calculating target NO.sub.2 production, obtaining a target DOC reaction temperature corresponding to the target NO.sub.2 production from the DOC reaction map, and adjusting a fuel injection rate so that the DOC reaction temperature is equal to the target DOC reaction temperature.

A method is disclosed for controlling an engine assembly comprising an internal combustion engine and an exhaust gas treatment apparatus. The aftertreatment assembly may require cleaning from time to time, and where this involves active thermal management of the aftertreatment assembly, the method involves performing the following steps: (a) imposing a first limit on engine speed; (b) awaiting an engine safe state; and (c) implementing a cleaning process comprising: (i) injecting fuel into the engine such that the fuel passes through the engine without combusting for the fuel to combust in the diesel oxidation catalyst so as to target an increase in exhaust gas temperature in the diesel oxidation catalyst; and (ii) removing the first limit on engine speed and targeting an engine speed set point, wherein the engine speed set point is at a higher speed than the first limit on engine speed.

A control system for a vehicle, the control system comprising one or more controllers, the control system being arranged to: determine a prediction of an end of a current driving cycle of the vehicle, determine a likelihood of slippage from an emissions trap of the vehicle in a next driving cycle of the vehicle in dependence on the prediction of the end of the current driving cycle, and control purging of the emissions trap prior to the prediction of the end of the current driving cycle in dependence on the likelihood of slippage.

A method of diagnosing an engine system including an engine and an exhaust aftertreatment system. The engine system comprises a plurality of replaceable engine system components. The method comprises maintaining a database with component data comprising, for each one of the replaceable engine system components, a deterioration efficiency parameter correlating the deterioration status of the replaceable engine system component to emission reducing efficiency, and a utility component parameter comprising component exchangeability data; determining the deterioration status of each one of the replaceable engine system components; estimating the emission reducing efficiency for each one of the replaceable engine system components in response to the determined deterioration status and the deterioration efficiency parameter; based on known relation between component exchangeability data and the resulting emission reducing efficiency of a potential exchange of the replaceable engine system component, identifying a replaceable engine system component to exchange.