A dosing module control system includes a central controller, a flow observer, and a switching doser controller. The central controller is configured to obtain a target flow rate and a target pressure. The flow observer is configured to determine a flow rate gain. The switching doser controller is configured to communicate with the central controller and the flow observer. The switching doser controller is configured to receive the target flow rate and the target pressure from the central controller, receive the flow rate gain from the flow observer, determine a compensated flow rate based on the target flow rate, the target pressure, and the flow rate gain, and determine at least one of an injector duty cycle associated with the determined compensated flow rate, or a pump frequency associated with the determined compensated flow rate. The pump is configured to communicate with the switching doser controller.

A method for controlling an exhaust gas treatment system is provided. The exhaust gas treatment system includes an exhaust gas stream supplied by an exhaust gas source to a selective catalytic reduction device, and a reductant supply source utilizing a volumetric pump. The exhaust gas source can include an internal combustion engine (ICE), such as a gasoline or diesel ICE. The method for controlling an exhaust gas treatment system includes commanding a reductant dosing quantity, determining a volumetric pump energizing time, determining an energizing time correction, and energizing the pump. The volumetric pump can comprise pump logic, and the volumetric pump energizing time can be determined by the pump logic. The energizing time correction can be determined using a calibration table. The calibration table can prescribe an energizing time correction based on a current pump pressure and the commanded dosing quantity.

An exhaust gas after-treatment unit for an internal combustion engine, particularly for a motor vehicle, includes a first selective catalytic reduction (SCR) catalytic converter through which the exhaust gas from the internal combustion engine can flow and at least one particle filter for retaining the soot particles from the exhaust gas, The particle filter, which is located downstream from the first SCR catalytic converter, is equipped with a heavy metal and precious metal free catalyzing coating which oxidizes the soot particles retained by the particle filter, where downstream from the particle filter there is a second SCR catalytic converter through which the exhaust gas can flow.

A computer program, system and method are provided for thermally regulating an injector injecting a reducing agent into an exhaust pipe of an internal combustion engine. A pump is activated to deliver a coolant in a coolant circuit having a portion in heat exchange relation with the injector. A value is determined for a mass flow rate of the coolant delivered by the pump. A value is calculated for a temperature of the injector as a function of the determined value of the mass flow rate. A difference is calculated between the calculated value of the injector temperature and a predetermined set-point value thereof, and the mass flow rate of the coolant delivered by the pump is adjusted on the basis of the calculated difference.

An aftertreatment system comprises a first SCR system, a second SCR system positioned downstream of the SCR system and a reductant storage tank. At least one reductant insertion assembly is fluidly coupled to the reductant storage tank. The at least one reductant insertion assembly is also fluidly coupled to the first SCR system and the SCR system. A controller is communicatively coupled to the reductant insertion assembly. The controller is configured to instruct the reductant insertion assembly to asynchronously insert the reductant into the first SCR system and the second SCR system.

Technical solutions are described for an emissions control system for a motor vehicle including an internal combustion engine. The emissions control system includes a reductant injector device, a selective catalytic reduction (SCR) device, and a controller. The controller determines a reductant energizing time for the reductant injector device based on one or more operating conditions of the SCR device. The controller further computes a diagnostic adaptation factor for the reductant energizing time based on an on-board diagnostic signal. The controller further inputs an amount of reductant into the SCR device by adjusting a reductant energizing time of the reductant injector device according to the diagnostic adaptation factor.

The present invention relates to a method for determining when to correct supply of additive to an exhaust gas stream resulting from combustion in at least one combustion chamber, wherein the additive is arranged for reduction of at least one substance resulting from said combustion by supplying the additive to an exhaust gas stream resulting from said combustion. The quantity of additive being supplied is subjectable to correction, and a sensor is subjected to the exhaust gas stream and arranged to measure occurrence of said at least one substance. The method comprises: by means of sensor signals from said sensor, determining a level of occurrence of said first substance in said exhaust gas stream, and determining when to correct said supply of additive on the basis of said occurrence of said first substance in said exhaust gas stream.

In an assembly and methods for NO.sub.x reductant dosing with variable spray angle nozzle, according to various embodiments, a reductant dosage is calculated. A reductant delivery region in an exhaust stream area of an aftertreatment system and an actuation period may be specified. Based at least on the reductant delivery region and the actuation period, the reductant insertion assembly may be placed in a state for reductant delivery such that one of a first array of reductant insertion ports and a second array of reductant insertion ports is in an open position. The shape of the variable spray angle nozzle may define different levels. Different arrays of reductant delivery ports may have varying operating characteristics, such as diameter, number of ports, actuation time, and/or reagent delivery angle and may be activated based on reductant flow pressure and/or reductant flow velocity.

A method for controlling an SCR system having two metering valves and a feed pump, wherein the two metering valves are operated in such a way that a reducing agent solution is metered in simultaneously via the two metering valves, at least over part of a metering time period (t.sub.Dos).

An arrangement for testing or treating a dosing valve of a dosing device of a dosing system in a vehicle includes connecting an electrical test drive to an electrical connector of the dosing device and connecting a dosing tester to a liquid inlet of the dosing device. Thereafter, an outlet valve of the dosing tester is opened to provide liquid under pressure to a liquid inlet of the dosing device. After a first given time, the electrical test drive provides pulses to repeatedly attempt to open the dosing valve. Upon a reduction in liquid level of liquid within the dosing tester in response to opening of the dosing valve, an operator closes the outlet valve of the dosing tester to discontinue the treatment.