Abstract: Methods and systems are provided for adjusting an ammonia (NH3) sensor output using readings of a nitrogen oxide (NOx) sensor, the NOx sensor having a sensitivity factor to NH3. In one example, a method may include determining and updating a gain value of the NH3 sensor during zero NOx conditions to be used to calculate a corrected NH3 sensor output value, and determining and updating an offset value of the NH3 sensor during zero NH3 conditions to be used to zero the NH3 sensor during zero NOx conditions.

Abstract: Methods and systems are provided for adjusting an ammonia (NH3) sensor output using readings of a nitrogen oxide (NOx) sensor, the NOx sensor having a sensitivity factor to NH3. In one example, a method may include determining and updating a gain value of the NH3 sensor during zero NOx conditions to be used to calculate a corrected NH3 sensor output value, and determining and updating an offset value of the NH3 sensor during zero NH3 conditions to be used to zero the NH3 sensor during zero NOx conditions.

Abstract: A method of operating a gas sensor is disclosed, wherein the sensor includes a pumping electrode configuration and a measuring electrode configuration, and wherein the method includes operating the sensor in a first mode in which a first, lower pumping potential sufficient to electrochemically remove an interfering compound from the sensor without electrochemically removing the analyte from the sensor is applied across the pumping electrode configuration and a measuring potential sufficient to electrochemically remove the analyte from the sensor is applied across the measuring electrode configuration; and operating the sensor in a second mode in which a second, higher pumping potential sufficient to electrochemically remove the analyte from the sensor is applied to the pumping electrode configuration.

Abstract: A method of operating a gas sensor is disclosed, wherein the sensor includes a pumping electrode configuration and a measuring electrode configuration, and wherein the method includes operating the sensor in a first mode in which a first, lower pumping potential sufficient to electrochemically remove an interfering compound from the sensor without electrochemically removing the analyte from the sensor is applied across the pumping electrode configuration and a measuring potential sufficient to electrochemically remove the analyte from the sensor is applied across the measuring electrode configuration; and operating the sensor in a second mode in which a second, higher pumping potential sufficient to electrochemically remove the analyte from the sensor is applied to the pumping electrode configuration.

Abstract: A method of operating a gas sensor is disclosed, wherein the sensor includes a pumping electrode configuration and a measuring electrode configuration, and wherein the method includes operating the sensor in a first mode in which a first, lower pumping potential sufficient to electrochemically remove an interfering compound from the sensor without electrochemically removing the analyte from the sensor is applied across the pumping electrode configuration and a measuring potential sufficient to electrochemically remove the analyte from the sensor is applied across the measuring electrode configuration; and operating the sensor in a second mode in which a second, higher pumping potential sufficient to electrochemically remove the analyte from the sensor is applied to the pumping electrode configuration.

Abstract: A system and method for improving sensor performance of an on-board vehicle sensor, such as an exhaust gas sensor, while sensing a predetermined substance in a fluid flowing through a pipe include a structure for extending into the pipe and having at least one inlet for receiving fluid flowing through the pipe and at least one outlet generally opposite the at least one inlet, wherein the structure redirects substantially all fluid flowing from the at least one inlet to the sensor to provide a representative sample of the fluid to the sensor before returning the fluid through the at least one outlet.

Abstract: A method of operating an electrochemical gas sensor is disclosed, wherein the method includes applying a voltage pulse across a measuring electrode pair, and detecting a current through the measuring electrode pair during the voltage pulse before the current decays to a steady state level.

Abstract: A system and method for improving sensor performance of an on-board vehicle sensor, such as an exhaust gas sensor, while sensing a predetermined substance in a fluid flowing through a pipe include a structure for extending into the pipe and having at least one inlet for receiving fluid flowing through the pipe and at least one outlet generally opposite the at least one inlet, wherein the structure redirects substantially all fluid flowing from the at least one inlet to the sensor to provide a representative sample of the fluid to the sensor before returning the fluid through the at least one outlet.

Abstract: An emissions treatment device includes a substrate having multiple parallel channels/layers of a porous material, the channels/layers including a first group of channels/layers at least partially open along their length from an upstream end to a downstream end, and a second group of channels/layers that are at least partially open at the downstream end and may be substantially blocked at an upstream end, the parallel channels having complementary geometries and/or sizes. Coated metallic fibers or fleece facilitates flow of exhaust through walls of the first group into the second group of channels. Flow diverters or scoops may be formed in the walls between the first and second groups of channels to divert exhaust flow from the first group to the second group of channels. Catalyzed mesh sheets may be supported by perforated stainless steel sheets containing small passages and/or scoops to complement the useful wallflow by structure and flow design.

Abstract: A method of operating a gas sensor is disclosed, wherein the sensor includes a pumping electrode configuration and a measuring electrode configuration, and wherein the method includes operating the sensor in a first mode in which a first, lower pumping potential sufficient to electrochemically remove an interfering compound from the sensor without electrochemically removing the analyte from the sensor is applied across the pumping electrode configuration and a measuring potential sufficient to electrochemically remove the analyte from the sensor is applied across the measuring electrode configuration; and operating the sensor in a second mode in which a second, higher pumping potential sufficient to electrochemically remove the analyte from the sensor is applied to the pumping electrode configuration.

Abstract: A method is presented for determining an amount of reductant stored in the catalyst by intrusively desorbing a portion of reductant and monitoring the response of an reductant sensor to the desorbed portion. The desorbtion can be performed at vehicle start-up to determine initial storage amount and to adjust reductant injection accordingly to achieve optimum storage. Additionally, a portion of reductant can be desorbed when NOx conversion efficiency of the catalyst is reduced in order to diagnose the component responsible for system degradation.

Abstract: A method is presented for determining an amount of reductant stored in the catalyst by intrusively desorbing a portion of reductant and monitoring the response of a reductant sensor to the desorbed portion. The desorbtion can be performed at vehicle start-up to determine initial storage amount and to adjust reductant injection accordingly to achieve optimum storage. Additionally, a portion of reductant can be desorbed when NOx conversion efficiency of the catalyst is reduced in order to diagnose the component responsible for system degradation.

Abstract: An exhaust aftertreatment device for an internal combustion engine is disclosed which contains multiple, parallel channels of a porous material, such as cordierite or silicon carbide, in which about some of the channels are plugged at an upstream end and other channels remain unplugged. In one embodiment, the substrate has an SCR coating and the engine has a urea supply system. Other embodiments include using TWC and LNT formulations. Several washcoat configurations and other specific geometries and dimensions to encourage crossflow, diffusion, and adsorption are disclosed herein.

Abstract: An improved engine control system using a NOx sensor is disclosed. In one example, the NOx sensor structure and/or signals are modified to improve distance transmission of NOx sensor output signals so that at least some processing electronics can be relocated remote to the sensor and in an engine control unit, or other such control unit utilizing the NOx sensor signals, and controlling the NOx sensor heaters, if applicable.

Abstract: An improved engine control system using a NOx sensor is disclosed. In one example, the NOx sensor structure and/or signals are modified to improve distance transmission of NOx sensor output signals so that at least some processing electronics can be relocated remote to the sensor and in an engine control unit, or other such control unit utilizing the NOx sensor signals, and controlling the NOx sensor heaters, if applicable.