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 calculating reaction heat in an exhaust system of an internal combustion engine by means of a model, comprising a first model component and a second model component, wherein the first model component refers to a calculation of exhaust components flowing from valves of the internal combustion engine, the second model component relates to the entire exhaust system, and total masses from the first model component are divided along the exhaust system onto the individual components of the exhaust system.

The muffler for a motorized vehicle includes a housing with an inlet chamber and an outlet chamber, an exhaust inlet, and an exhaust outlet. The muffler includes a first channel with a first noise dampening amount that is within the housing interior, to fluidly connect the inlet chamber and the outlet chamber. The muffler includes second channel with a second noise dampening amount that is within the housing interior between the inlet chamber and the outlet chamber. The first noise dampening amount is greater than the second noise dampening amount. A valve selectively fluidly connects the inlet chamber and the outlet chamber thorough the second channel, and is configured to variably obstruct the flow of exhaust gas through the second channel. In various embodiments, the muffler has more than one inlet chamber and more than one exhaust outlet.

Methods and systems for operating an engine that includes a low pressure EGR passage and a selective reduction catalyst are disclosed. In one example, an actuator is adjusted in response to a NOx mass flow rate in the low pressure EGR passage.

A method for injecting a reductant into an exhaust gas of a power system. The method includes oscillating injections of the reductant between a higher reductant injection rate and a lower reductant injection rate. The higher injection rate is high enough to result in storage of a decomposed form of the reductant on a selective catalytic reduction on-filter (SCR+F), and the lower injection rate being low enough to result in depletion of the decomposed form of the reductant on the SCR+F. The SCR+F includes a diesel particular filter and a selective catalytic reduction catalyst applied thereto.

In a method for dynamic monitoring of gas sensors of an internal combustion engine, in the event of a change of the gas state variable to be measured, a dynamic diagnosis is carried out based on a comparison of a measured signal which is an actual value of an output signal of the gas sensor and a modeled signal which is a model value. The output signal of the gas sensor is filtered using a high-pass filter and higher-frequency signal components are analyzed.

In a multi-gas sensor control apparatus 1, the concentrations of ammonia, NO.sub.2, and NO contained in a gas under measurement are computed as a result of execution of gas concentration computation processing by a CPU 61 of a microcomputer 60. In the gas concentration computation processing, depending on whether or not a correction permission condition is satisfied (S200), the CPU 61 switches its operation between an operation of storing the latest corrected ammonia concentration as a value of NH.sub.3 concentration (this time) (S170) and an operation of storing a value of NH.sub.3 concentration (reference) as a value of NH.sub.3 concentration (this time) (S210). The multi-gas sensor control apparatus 1 can suppress a decrease in the accuracy of detection of the ammonia concentration performed through use of a multi-gas sensor 2.

An exhaust system for an internal combustion engine for a vehicle includes a turbine positioned in an exhaust stream from the internal combustion engine, a first diesel oxidation catalyst positioned upstream of the turbine within the exhaust stream, and a bypass for selectively bypassing the exhaust stream around the diesel oxidation catalyst to the turbine.

Exhaust aftertreatment assemblies and methods of manufacturing and operating exhaust aftertreatment assemblies. The exhaust aftertreatment assembly includes a reductant delivery device, a reductant source fluidly coupled to the reductant delivery device, a mixing chamber positioned between the reductant delivery device and the reductant source and thereby fluidly coupling the reductant source to the reductant delivery device, and a compressed air source fluidly coupled to the mixing chamber upstream of the mixing chamber with respect to the reductant delivery device. The compressed air source provides compressed air to mix with reductant in the mixing chamber.

An exhaust system for an internal combustion engine for a vehicle includes a turbine positioned in an exhaust stream from the internal combustion engine, a first diesel oxidation catalyst positioned upstream of the turbine within the exhaust stream, and a bypass for selectively bypassing the exhaust stream around the diesel oxidation catalyst to the turbine.