Technical solutions described herein include an emissions control system for treating exhaust gas in a motor vehicle including an internal combustion engine. The emissions control system includes a model-based controller to control reductant injections into the exhaust gas. Controlling the reductant injections includes determining an amount of NOx and an amount of NH3 at an outlet of the first SCR device, and at an outlet of the second SCR device. The controlling further includes computing an amount of reductants to inject to maintain a first predetermined ratio between the amount of NH3 and the amount of NOx at the outlet of the first SCR device and to maintain a second predetermined ratio between the amount of NH3 and the amount of NOx at the outlet of the second SCR device. Further, the controlling includes sending a command for receipt by the reductant injectors to inject the computed amount of reductants.

Technical solutions described herein include an emissions control system for treating exhaust gas in a motor vehicle including an internal combustion engine. The emissions control system includes a model-based controller to control reductant injections into the exhaust gas. Controlling the reductant injections includes determining an amount of NOx and an amount of NH3 at an outlet of the first SCR device, and at an outlet of the second SCR device. The controlling further includes computing an amount of reductants to inject to maintain a first predetermined ratio between the amount of NH3 and the amount of NOx at the outlet of the first SCR device and to maintain a second predetermined ratio between the amount of NH3 and the amount of NOx at the outlet of the second SCR device. Further, the controlling includes sending a command for receipt by the reductant injectors to inject the computed amount of reductants.

A method of predicting the temperature of a resistive heating element in a heating system is provided. The method includes obtaining resistance characteristics of resistive heating elements and compensating for variations in the resistance characteristics over a temperature regime. The resistance characteristics of the resistive heating element include, but are not limited to, inaccuracies in resistance measurements due to strain-induced resistance variations, variations in resistance due to the rate of cooling, shifts in power output due to exposure to temperature, resistance to temperature relationships, non-monotonic resistance to temperature relationships, system measurement errors, and combinations of resistance characteristics. The method includes interpreting and calibrating resistance characteristics based on a priori measurements and in situ measurements.

An exhaust gas treatment system for an internal combustion engine includes an exhaust gas pathway that receives exhaust gas from the engine, a temperature sensor configured to generate a temperature signal associated with a temperature of the exhaust gas at a position along the exhaust gas pathway, and a reductant source. The system also includes first and second injectors in fluid communication with the reductant source. The first and second injectors are configured to inject reductant into the exhaust gas pathway at first and second rates. The system also includes a first treatment element positioned downstream of the first injector and within the exhaust gas pathway, and a controller in communication with the temperature sensor. The controller is configured to receive the temperature signal from the temperature sensor and adjust at least one of the first rate or the second rate based at least in part on the temperature signal.

A system, apparatus, and method are provided for preventing the accumulation of particulate matter such as combustion soot on sensors positioned in exhaust gas conduits of internal combustion engines. In an embodiment, the apparatus includes a device for deflecting soot deposits from sensor surfaces. In an embodiment, the apparatus includes a device employing a surface acoustic wave generator for dislodging soot accumulation or measuring soot accumulations to trigger burn-off events. In an embodiment, an injector injects pressurized bursts of gas toward a sensor surface to dislodge particulate matter. In an embodiment, charged electrodes attract charged particles of soot from the exhaust gas flow to form deposits that are then subject to burn-off events.

A catalyst state estimation apparatus includes a first sensor, a memory and a processor. The first sensor is configured to acquire information about a catalyst that removes a toxic substance in an exhaust gas, the first sensor being provided in a main passage into which the exhaust gas flows from an internal combustion engine. The memory is configured to previously store a catalyst state estimation model that includes at least one mathematical model. The processor is configured to estimate a removal performance of the catalyst by applying the information about the catalyst acquired by the first sensor to the catalyst state estimation model.

A method is provided for managing the light-off of a 3-way catalytic converter that is located in an exhaust line of a petrol engine having a plurality of cylinders with each cylinder having at least one exhaust valve. The method includes calculating a value of enthalpy of exhaust gases to make it possible to determine a quantity of heat supplied to the three-way catalyst, determining a threshold enthalpy value signaling the light-off of the catalyst, and stopping of activation of the three-way catalyst upon determining the value of the enthalpy that was calculated has reached the threshold enthalpy value.

A DEF injector is connected to the exhaust system of a vehicle upstream of an SCR catalyst, and is further connected to the ECU or DCU. An exhaust temperature sensor and an exhaust mass flow rate sensor are connected to the ECU or DCU, and further connected to the DEF injector. The ECU or DCU controls the DEF injector based on exhaust temperature and exhaust mass flow rate when the exhaust temperature is above a certain threshold. The DEF injector itself, or a dedicated DEF injector controller, overrides and/or supplements the control logic located within the ECU or DCU to control the DEF injector to inject DEF at reduced rates when the exhaust temperature and/or the exhaust mass flow rate are lower than the threshold for DEF injection set by the ECU or DCU.

A heating system includes at least one electric heater disposed within the fluid flow system. A control device includes a microprocessor and is configured to determine a temperature of the at least one electric heater based on a model and at least one input from the fluid flow system. The control device is configured to provide power to the at least one electric heater based on the temperature of the at least one electric heater.

A system for determining an exhaust flow rate of an exhaust gas produced by an engine comprises a first sensor configured to measure an amount of NOx gases in the exhaust gas. A controller is communicatively coupled to the first sensor. The controller is configured to receive a first sensor signal from the first sensor. The controller is also configured to receive a fuel rate signal corresponding to a rate of fuel consumption by the engine. The controller is configured to determine an air-fuel ratio from the first sensor signal and determine a fuel rate from the fuel rate signal. Furthermore, the controller is configured to determine the exhaust flow rate from the air-fuel ratio and the fuel rate.