Systems and methods for managing mass flow splits in aftertreatment systems

Abstract

A system, method, and apparatus for managing mass flow split in a multi-path aftertreatment system are provided. The system may include an aftertreatment system including a first path and a second path and a controller. The controller estimates a first mass flow rate in the first path and a second mass flow rate in the second path. The controller calculates an estimated total mass flow rate based on the estimated first and second mass flow rates. In response to determining that the estimated total mass flow rate is greater than the engine exhaust mass flow rate, the controller calculates a correction factor. The controller uses the correction factor to estimate corrected first and second mass flow rates in the first and second path. The controller adjusts at least one of reductant dosing, hydrocarbon dosing, or soot loading estimation based on the corrected first and second mass flow rates.

Description

[Technical Field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application is a national stage application of PCT / US2022 / 050347, filed November 18, 2022, the contents of which are incorporated herein by reference.

[0002] FIELD OF THE INVENTION This application relates generally to aftertreatment systems, and more particularly to managing mass flow splits in aftertreatment systems. [Background technology]

[0003] Internal combustion engines such as diesel engines emit nitrogen oxides (NO x ) compounds. For example, to comply with environmental regulations, x Reducing emissions may be desirable. x To reduce emissions, a reductant can be dosed into the exhaust by a dosing system in the aftertreatment system. The reductant cooperates with a catalyst in the catalytic member to convert a portion of the exhaust into non-NOx compounds such as nitrogen (N), carbon dioxide (CO), and water (HO). x promotes the conversion of NO into excreta x In some applications, these compounds in the exhaust can be filtered or removed by one or more catalytic components located in the aftertreatment system (e.g., a diesel oxidation catalyst (DOC) component, a selective catalytic reduction (SCR) catalyst component, a diesel particulate filter (DPF) component, an ammonia oxidation (AMOx) catalyst component, etc.). Summary of the Invention

[0004] An aftertreatment system may include multiple flow paths for reducing exhaust byproducts in exhaust gases generated from an internal combustion engine. Each flow path in the aftertreatment system has one or more components for reducing the exhaust byproducts, such as a catalyst member (e.g., an SCR catalyst member, a DOC member, etc.) or a filter (e.g., a DPF member, etc.). The mass flow rate of the exhaust byproducts traversing each flow path may be used to determine a dosage of ammonia (NH) (e.g., a reductant) for reducing the exhaust byproducts.

[0005] However, due to certain piping restrictions or blockages within the aftertreatment system, the exhaust gas mass flow split may be uneven across the flow paths (e.g., the exhaust gas flow rate in one flow path may be different from that in another flow path). Mass flow split refers to the percentage of mass flow (or mass flow rate) split across the flow paths of the aftertreatment system. This restriction may be caused by many factors, including, but not limited to, an asymmetric tailpipe or other improper installation of the aftertreatment system, soot loading, deposits, etc. Restrictions within the aftertreatment system cause inaccuracies in mass flow estimation, which may affect at least reductant dosage, hydrocarbon (HC) dosage, and / or soot loading estimation. Therefore, the systems, methods, and apparatus described herein are configured to identify any restrictions within the aftertreatment system and provide corrections to the mass flow estimation, thereby adjusting at least one of reductant dosage, HC dosage, and / or soot loading estimation according to the flow split to, for example, minimize reductant slip, untimely triggering of a regeneration event, or insufficient regeneration control.

[0006] In some embodiments, an aftertreatment system includes a first flow path including one or more first aftertreatment components, a second flow path including one or more second aftertreatment components, and a controller. The controller is configured to estimate a first mass flow rate of exhaust gas in the first flow path. The controller is configured to estimate a second mass flow rate of exhaust gas in the second flow path. The controller is configured to calculate an estimated total mass flow rate based on the estimated first mass flow rate and the estimated second mass flow rate. In response to determining that the estimated total mass flow rate is greater than the engine exhaust mass flow rate, the controller is configured to calculate a correction factor to balance the estimated first mass flow rate and the estimated second mass flow rate. The controller is configured to use the correction factor to estimate a corrected first mass flow rate of exhaust gas in the first flow path and a corrected second mass flow rate of exhaust gas in the second flow path. The controller is configured to adjust at least one of reductant dosing, hydrocarbon dosing, or soot loading estimation based on the corrected first mass flow rate and the corrected second mass flow rate.

[0007] In some embodiments, the controller is configured to regenerate at least one of a first selective catalytic reduction (SCR) catalyst of the one or more first aftertreatment components or a second SCR catalyst of the one or more second aftertreatment components in response to determining that the estimated total mass flow rate is greater than the engine exhaust mass flow rate before calculating the correction factor. In some embodiments, after regenerating at least one of the first SCR catalyst or the second SCR catalyst and before calculating the correction factor, the controller is further configured to estimate a third mass flow rate of the exhaust gas in the first flow path, estimate a fourth mass flow rate of the exhaust gas in the second flow path, and calculate a second estimated total mass flow rate based on the third mass flow rate and the fourth mass flow rate.

[0008] In some embodiments, in response to determining that the estimated total mass flow rate is greater than the engine exhaust mass flow rate, the controller is further configured to determine whether the first flow path or the second flow path is newly installed, and to calculate a correction factor in response to determining that the first flow path or the second flow path is newly installed. To calculate the correction factor, the controller is configured to determine a ratio between a first pressure differential value across a first particulate filter of the one or more first aftertreatment components and a second pressure differential value across a second particulate filter of the one or more second aftertreatment components, and to calculate the correction factor based on the ratio between the first pressure differential value and the second pressure differential value.

[0009] In some embodiments, in response to determining that the estimated total mass flow rate is greater than the engine exhaust mass flow rate, the controller is further configured to determine whether the first flow path or the second flow path has been newly installed, and in response to determining that neither the first flow path nor the second flow path has been newly installed, estimate a soot loading flow rate and calculate a correction factor based on the estimated soot loading flow rate.

[0010] In some embodiments, the controller is further configured to estimate a first virtual mass flow rate of the exhaust gases in the first flow path based on a first pressure differential value across a first particulate filter of the one or more first after-treatment components. The controller is configured to estimate a second virtual mass flow rate of the exhaust gases in the second flow path based on a second pressure differential value across a second particulate filter of the one or more second after-treatment components. The controller is configured to calculate a correction factor based on the engine exhaust mass flow rate and at least one of the estimated first virtual mass flow rate or the estimated second virtual mass flow rate.

[0011] In some embodiments, the controller is further configured to determine a first pressure differential value across a first particulate filter of the one or more first aftertreatment components and a second pressure differential value across a second particulate filter of the one or more second aftertreatment components over a time window including a plurality of time intervals. The controller is configured to compare the first pressure differential value and the second pressure differential value with a set of calibrated tables including a plurality of predetermined pressure differential values ​​for different flow splits of the engine exhaust mass flow rate at the end of the time window. The controller is configured to calculate a correction factor based on a comparison between the first pressure differential value and the second pressure differential value against the set of calibrated tables at the end of the time window.

[0012] In some embodiments, to calculate the correction factor, the controller is further configured to increment a score of one of the sets of calibrated tables in response to the first pressure differential value and the second pressure differential value matching one of the sets of calibrated tables in each of a plurality of time intervals of the time window, and at the end of the time window, select the flow split corresponding to the set of calibrated tables with the highest score for calculating the correction factor.

[0013] In some embodiments, the method includes estimating, by a controller, a first mass flow rate of the exhaust gas in a first flow path including one or more first aftertreatment components; estimating, by the controller, a second mass flow rate of the exhaust gas in a second flow path including one or more second aftertreatment components; calculating, by the controller, an estimated total mass flow rate based on the estimated first mass flow rate and the estimated second mass flow rate; in response to determining that the estimated total mass flow rate is greater than the engine exhaust mass flow rate, calculating, by the controller, a correction factor to balance the estimated first mass flow rate and the estimated second mass flow rate; estimating, by the controller, a corrected first mass flow rate of the exhaust gas in the first flow path and a corrected second mass flow rate of the exhaust gas in the second flow path using the correction factor; and adjusting, by the controller, at least one of reductant dosing, hydrocarbon dosing, or soot loading estimation based on the corrected first mass flow rate and the corrected second mass flow rate.

[0014] In some embodiments, the method further includes, in response to determining that the estimated total mass flow rate is greater than the engine exhaust mass flow rate, regenerating, by the controller, at least one of a first selective catalytic reduction (SCR) catalyst of the one or more first aftertreatment components or a second SCR catalyst of the one or more second aftertreatment components before calculating the correction factor.

[0015] In some embodiments, following regenerating at least one of the first SCR catalyst or the second SCR catalyst and prior to calculating the correction factor, the method further includes estimating, by the controller, a third mass flow rate of the exhaust gas in the first flow path; estimating, by the controller, a fourth mass flow rate of the exhaust gas in the second flow path; and calculating, by the controller, a second estimated total mass flow rate based on the third mass flow rate and the fourth mass flow rate.

[0016] In some embodiments, in response to determining that the estimated total mass flow is greater than the engine exhaust mass flow, the method includes determining, by the controller, whether the first flow path or the second flow path is newly installed, and calculating, by the controller, a correction factor in response to determining that the first flow path or the second flow path is newly installed.

[0017] In some embodiments, calculating the correction factor includes determining, by the controller, a ratio between a first pressure differential value across a first particulate filter of the one or more first aftertreatment components and a second pressure differential value across a second particulate filter of the one or more second aftertreatment components, and calculating, by the controller, the correction factor based on the ratio between the first pressure differential value and the second pressure differential value.

[0018] In some embodiments, in response to determining that the estimated total mass flow rate is greater than the engine exhaust mass flow rate, the method includes determining, by the controller, whether the first flow path or the second flow path has been newly installed; and, in response to determining, by the controller, that neither the first flow path nor the second flow path has been newly installed, estimating a soot loading flow rate; and calculating, by the controller, a correction factor based on the estimated soot loading flow rate.

[0019] In some embodiments, the method further includes estimating, by the controller, a first virtual mass flow rate of the exhaust gases in the first flow path based on a first pressure differential value across a first particulate filter of the one or more first after-treatment components; estimating, by the controller, a second virtual mass flow rate of the exhaust gases in the second flow path based on a second pressure differential value across a second particulate filter of the one or more second after-treatment components; and calculating, by the controller, a correction factor based on the engine exhaust mass flow rate and at least one of the estimated first virtual mass flow rate or the estimated second virtual mass flow rate.

[0020] In some embodiments, the method further includes determining, by the controller, a first pressure differential value across a first particulate filter of the one or more first aftertreatment components and a second pressure differential value across a second particulate filter of the one or more second aftertreatment components over a time window comprising a plurality of time intervals; comparing, by the controller, the first pressure differential value and the second pressure differential value at each of the plurality of time intervals to a set of calibration tables comprising a plurality of predetermined pressure differential values ​​for different flow splits of the engine exhaust mass flow; and calculating, by the controller, at the end of the time window, a correction factor based on the comparison between the first pressure differential value and the second pressure differential value against the set of calibration tables.

[0021] In some embodiments, calculating the correction factor includes, in response to the first pressure differential value and the second pressure differential value matching one of the set of calibrated tables during each of a plurality of time intervals of the time window, incrementing the score of one of the set of calibrated tables by the controller, and, at the end of the time window, selecting, by the controller, the flow split corresponding to the set of calibrated tables having the highest score for calculating the correction factor.

[0022] In some embodiments, the aftertreatment system includes a first flow path including one or more first aftertreatment components, a second flow path including one or more second aftertreatment components, and a controller. The controller controls the first NO in the first flow path. x The controller is configured to calculate a conversion efficiency of the second NO 2 in the second flow path. x The controller is configured to calculate a conversion efficiency of the first NO x Conversion efficiency and second NO x Average NO based on conversion efficiency x The controller is configured to calculate a conversion efficiency of the first NO x Conversion efficiency and second NO x The conversion efficiency is calculated based on the difference between the average NO xThe conversion efficiency is less than a first threshold value or the first NO x Conversion efficiency and second NO x In response to determining whether the difference between the conversion efficiency and the estimated first mass flow rate is greater than a first threshold, the controller is configured to calculate an adjustment factor to balance the estimated first mass flow rate and the estimated second mass flow rate. The controller is configured to estimate an adjusted first mass flow rate of the exhaust gas in the first flow path and an adjusted second mass flow rate of the exhaust gas in the second flow path using the adjustment factor. The controller is configured to adjust at least one of the reductant dosing, the hydrocarbon dosing, or the soot loading estimation based on the adjusted first mass flow rate and the adjusted second mass flow rate.

[0023] In some embodiments, the average NO x The conversion efficiency is less than a first threshold value or the first NO x Conversion efficiency and second NO x In response to determining whether the difference between the calculated first NO conversion efficiency and the calculated first NO conversion efficiency is greater than a first threshold value, the controller x Conversion efficiency and calculated second NO x Based on the conversion efficiency, a low NO 2 concentration is obtained from one of the first flow path or the second flow path. x The controller is further configured to identify a low NO conversion efficiency flow path. x Conversion efficiency of ammonia (NH3) vs. NO x The controller is configured to determine a low NO ratio (ANR). x The controller is configured to compare the ANR of the conversion efficiency flow path with a second threshold. x and determining that the ANR of the conversion efficiency flow path is less than a second threshold. x Identify slip or low NO x and identifying NH3 slip in response to determining that the ANR of the conversion efficiency flow path is equal to or greater than a second threshold. x and calculating an adjustment factor for adjusting the dosing rate of the reductant in the aftertreatment system based on the slip or the NH3 slip.

[0024] In some embodiments, to regulate the rate of administration of the reducing agent, the controller x The system is further configured to increase a dosing rate of the reductant in the aftertreatment system by a first amount in response to the slip, or decrease a dosing rate of the reductant in the aftertreatment system by a second amount in response to the NH3 slip.

[0025] In some embodiments, the controller adjusts the dosing rate of the reductant to achieve a low NO x Conversion efficiency of the third NO flow path x The controller is further configured to calculate a conversion efficiency. x In response to determining that the conversion efficiency is less than a third threshold, the dosing rate of the reducing agent is configured to be readjusted.

[0026] In some embodiments, the controller adjusts the reductant dosage rate after the low NO x Conversion efficiency of the fourth NO flow path x The controller is configured to calculate the conversion efficiency of the fourth NO x A fault is configured to be triggered in response to determining that the conversion efficiency is less than a fourth threshold.

[0027] In some embodiments, the method further comprises: by the controller: x calculating a conversion efficiency and controlling, by the controller, a second NO in a second flow path including one or more second after-treatment components; x Calculating the conversion efficiency and determining the first NO x Conversion efficiency and second NO x Average NO based on conversion efficiency x Calculating the conversion efficiency and determining the first NO x Conversion efficiency and second NO x Calculate the difference between the conversion efficiency and the average NO x The conversion efficiency is less than a first threshold value or the first NO xConversion efficiency and second NO x In response to determining that a difference between the conversion efficiency and the estimated first mass flow rate is greater than a first threshold, the controller calculates an adjustment factor to balance the estimated first mass flow rate and the estimated second mass flow rate; the controller estimates an adjusted first mass flow rate of the exhaust gas in the first flow path and an adjusted second mass flow rate of the exhaust gas in the second flow path using the adjustment factor; and the controller adjusts at least one of reductant dosing, hydrocarbon dosing, or soot loading estimation based on the adjusted first mass flow rate and the adjusted second mass flow rate.

[0028] In some embodiments, the average NO x The conversion efficiency is less than a first threshold value or the first NO x Conversion efficiency and second NO x In response to determining that the difference between the conversion efficiency and the first NO is greater than a first threshold, the method includes, by the controller: x Conversion efficiency and calculated second NO x Based on the conversion efficiency, a low NO 2 concentration is obtained from one of the first flow path or the second flow path. x identifying a flow path for converting a low NO x Conversion efficiency of ammonia (NH3) vs. NO x determining an ANR by the controller; x comparing the ANR of the conversion efficiency flow path to a second threshold; and determining by the controller that the low NO x and detecting a NO in response to determining that the ANR of the conversion efficiency flow path is less than a second threshold. x Slip or low NO x identifying NH3 slip in response to determining that the ANR of the conversion efficiency flow path is greater than or equal to a second threshold; and determining by the controller that the NO x and calculating an adjustment factor for adjusting the dosing rate of the reductant in the aftertreatment system based on the slip or the NH3 slip.

[0029] In some embodiments, adjusting the rate of administration of the reducing agent is performed by the controller. x increasing a dosing rate of the reductant in the aftertreatment system by a first amount in response to the slip, or decreasing, by the controller, a dosing rate of the reductant in the aftertreatment system by a second amount in response to the NH3 slip.

[0030] In some embodiments, the method further comprises adjusting the administration rate of the reducing agent to provide a low NO x Conversion efficiency of the third NO flow path x The conversion efficiency is calculated by the controller, and the third NO x and readjusting, by the controller, the dosing rate of the reducing agent in response to determining that the conversion efficiency is less than a third threshold.

[0031] In some embodiments, the method further comprises readjusting, by the controller, the dosing rate of the reducing agent followed by a low NO x Conversion efficiency of the fourth NO flow path x Calculating the conversion efficiency and the controller x and triggering a fault in response to determining that the conversion efficiency is less than a fourth threshold. [Brief explanation of the drawings]

[0032] The details of one or more embodiments are set forth in the accompanying drawings and the description below. Other features, aspects, and advantages of the present disclosure will become apparent from the description, drawings, and claims.

[0033] It will be appreciated that some or all of the drawings are schematic for illustrative purposes, provided for the purpose of illustrating one or more embodiments, with the express understanding that they are not used to limit the scope or meaning of the claims.

[0034] [Figure 1] FIG. 1 is an exemplary schematic diagram of an engine exhaust aftertreatment system coupled to a controller. [Figure 2] FIG. 2 is an exemplary schematic diagram of a controller for use with the engine system of FIG. 1. [Figure 3] 10 is an example of a graph showing the correlation between mass flow split error versus restriction difference between flow paths. [Figure 4] 10 is an example of a graph showing the correlation between ammonia slip versus restriction difference between flow paths. [Figure 5] 1 is an exemplary graph illustrating pressure differential and volumetric flow rate (e.g., actual cubic meters per second (ACMS)) characteristics for a particular flow split. [Figure 6] 10 is another exemplary graph illustrating pressure differential and volumetric flow characteristics for a particular flow split. [Figure 7] FIG. 2 is a schematic process flow diagram of an exemplary process for managing mass flow split in a multi-path aftertreatment system of the engine system of FIG. 1. [Figure 8] FIG. 8 is an exemplary process flow diagram for performing the exemplary proportional correction of FIG. 7 in more detail. [Figure 9] 9 is a graph illustrating in greater detail certain exemplary operations associated with the delta pressure-based correction process of FIG. 8; [Figure 10] FIG. 9 is a block diagram illustrating the example matching model of FIG. 8 in more detail. [Figure 11] 9 is an exemplary graph depicting the model-based approach of FIG. 8 for inlet pipe restriction. [Figure 12] 9 is an exemplary graph depicting the model-based approach of FIG. 8 for tailpipe restriction. [Figure 13] 9 is an exemplary graph showing monitored data for the model-based approach of FIG. 8 matching 50-50 flow split data to respective flow split tables. [Figure 14] 9 is an exemplary graph showing monitored data for the model-based approach of FIG. 8 matching 40-60 flow split data to respective flow split tables. [Figure 15]9 is an exemplary graph illustrating monitored data for the model-based approach of FIG. 8 matching 60-40 flow split data to at least one respective flow split table. [Figure 16] 9 is an exemplary graph illustrating monitored data for the model-based approach of FIG. 8 matching test cell (TC) non-road transient cycle (NRTC) 50-50 flow split data to at least one respective flow split table. [Figure 17] FIG. 2 is a schematic process flow diagram of another exemplary process for managing mass flow split in a multi-path aftertreatment system of the engine system of FIG. 1. [Figure 18] 18 is a process flow diagram of an exemplary process for managing mass flow splitting in a multi-path aftertreatment system associated with FIG. 17, as will be described in further detail. [Figure 19] 19 is a graph of an exemplary process for NOx monitoring-based correction associated with FIG. 18. DETAILED DESCRIPTION OF THE INVENTION

[0035] The following describes a method, apparatus, and method for determining an efficiency value associated with a catalytic member: , and systems A more detailed description of various concepts related to, and embodiments thereof. The various concepts introduced above and described in more detail below may be implemented in any of several ways, as the concepts described are not limited to any particular implementation method. Examples of specific embodiments and applications are provided primarily for illustrative purposes.

[0036] 1. Overview

[0037] An internal combustion engine (e.g., a diesel internal combustion engine) produces exhaust (sometimes called exhaust gas). Depending on the fuel consumed by the internal combustion engine, the exhaust may contain different by-products (e.g., NO xThe exhaust by-products may include NO, carbon monoxide (CO), unburned hydrocarbons (HC), etc. The exhaust by-products are measured or sensed by one or more sensors in the aftertreatment system, which may measure, for example, the density, volume, parts per million (ppm) of the exhaust, etc. The aftertreatment system may be coupled to the engine, such as being connected via an exhaust pipe from the engine. For simplicity, the examples herein will focus on NO as an exhaust by-product. x The sensor can provide NO downstream of the engine (e.g., anywhere along the exhaust pipe). x configured to sense the emission of NO x The example described is a NO x Measuring by-products NO x Although the present invention includes a sensor, the described system can be applied to other sensors.

[0038] Exhaust by-products can be reduced by one or more aftertreatment components of the engine system, including an aftertreatment system such as a DOC member or an SCR catalyst member, among other types of catalysts. The aftertreatment system can include multiple flow paths. For simplicity, the examples herein provide an aftertreatment system including two flow paths, but the aftertreatment system can include more than two flow paths with respective components for reducing exhaust by-products. For example, exhaust can flow through or traverse the aftertreatment system via a first flow path and a second flow path. The catalyst member (e.g., an SCR catalyst member, a DOC member, etc.) in each flow path can promote a chemical reaction of the by-products and a reductant to reduce or minimize emissions from the tailpipe of the engine system. For simplicity, the examples herein can provide an SCR catalyst member or a DOC member as the catalyst member of the aftertreatment system. Each flow path of the aftertreatment system can be dosed with ammonia (NH3) (e.g., a reductant) to reduce exhaust by-products. The dosage of the reductant can be based on the exhaust gas mass flow rate of the exhaust gas traversing the respective flow path.

[0039] However, due to certain piping restrictions or blockages within the aftertreatment system, the mass flow split of the exhaust gas may be uneven across the flow paths (e.g., the flow rate in one flow path is different from that of another flow path). Mass flow split refers to the ratio / proportion / percentage of the mass flow (or mass flow rate) divided / shared between each flow path of the aftertreatment system. This restriction can be caused by many factors, including, but not limited to, asymmetric tailpipes or other improper installation of the aftertreatment system, soot buildup, deposits, etc. Furthermore, depending on the location of the restriction, measured pressure values ​​(e.g., catalyst outlet pressure) that may be used to estimate the mass flow rate in each flow path may not represent the actual mass flow rate of the flow path. This results in inaccurate mass flow estimation, which may affect at least reductant dosing, hydrocarbon (HC) dosing, and / or soot loading estimation. As a result, inaccurate mass flow estimation may result in at least one of, for example, NH3 slip, early or late regeneration triggering, and / or poor regeneration control. Therefore, it may be desirable to identify any restrictions in the aftertreatment system, calculate a correction / adjustment factor representing the actual mass flow split, correct the estimated mass flow according to the actual flow split between the flow paths, and subsequently adjust at least one of the reductant dosing, HC dosing, and / or soot loading estimates according to the flow split to, for example, minimize reductant slip, untimely triggering of a regeneration event, or insufficient regeneration control.

[0040] The systems and methods described herein include at least one controller (e.g., a computing device or data processing system) including at least one processor coupled to at least one memory. In some cases, the controller may be integrated into a system including an internal combustion engine, one or more sensors, and an aftertreatment system. In some cases, the controller may be external to the system, such as a server or cloud computing device that communicates with one or more components of the system. In this case, the controller is configured to receive data from the system, such as sensor data from sensors monitoring the internal combustion engine or the aftertreatment system.

[0041] In various configurations, the controller is configured to calculate or estimate the mass flow rates of exhaust gases passing through the flow paths (e.g., the first flow path and the second flow path) of the aftertreatment system. The controller can estimate the mass flow rates based on pressure data, such as a pressure differential across the catalyst (e.g., delta pressure) or the catalyst's outlet pressure. The controller is configured to calculate an estimated total mass flow rate based on the estimated mass flow rates. The controller is configured to compare the estimated mass flow rates with the exhaust gas mass flow rate from the engine to determine any flow division imbalance (e.g., uneven mass flow rates) between the flow paths. The imbalance may be caused by certain types of restrictions in the tailpipe or aftertreatment system, such as deposits, soot loading, asymmetric tailpipes (either by design or due to misalignment of at least one flow path), etc. The controller is configured to calculate a correction factor to balance the estimated mass flow rates. The correction factor can be based on a number of variables, including whether one or more components of the aftertreatment system have been regenerated, whether the aftertreatment system is newly installed, etc. By applying a correction factor to the estimated mass flow rate of each flow path, the controller is configured to estimate a corrected mass flow rate for the flow path and adjust at least one of the reductant dosing, hydrocarbon dosing, or soot loading estimation accordingly. xand minimize reductant slip and control regeneration triggering of one or more catalysts in an unbalanced aftertreatment system.

[0042] In a particular configuration, the controller may be configured to x The controller may be configured to utilize a conversion efficiency (e.g., NO) to determine imbalance between the flow paths and adjust the estimated mass flow rate. x Using sensors, NO x Calculate the conversion efficiency (e.g., NO over the aftertreatment system) x The controller is configured to monitor the reduction of NO in the flow path. x Based on conversion efficiency, NO x Average conversion efficiency or flow path NO x and then calculating at least one of the differences between the average NO x If at least one of the conversion efficiencies or the difference is less than a respective threshold, the controller is configured to calculate an adjustment factor (e.g., sometimes referred to as a correction factor). The controller is configured to estimate an adjusted mass flow rate by applying the adjustment factor to the estimated flow rate (e.g., based on the pressure data). Based on the adjusted mass flow rates across the first flow path and the second flow path, the controller is configured to adjust at least one of reductant dosing (e.g., dosing duration, frequency, or timing), hydrocarbon dosing, or soot loading estimation. Thus, the system and method can reduce NOx in the tailpipe. x and / or further minimize the amount of reducing agent, NO x Conversion efficiency can be maintained above a desired efficiency level.

[0043] Through these features, the embodiments described herein can warn a user regarding the use of impure fuel and can warn a user regarding the deterioration of catalyst components beyond a desired amount. As a result, the embodiments described herein can reduce costs associated with warranty service and / or replacement that may be performed when impure fuel is consumed by an engine system.

[0044] 2. Overview of the multi-channel aftertreatment engine system

[0045] Referring generally to the drawings, various embodiments disclosed herein relate to systems, apparatus, and methods for managing mass flow splits in a multi-passage aftertreatment system. x Aftertreatment systems to reduce harmful NOx present in exhaust gases (e.g., soot) x SCR systems utilize a two-stage process to reduce emissions, or include a DOC element to filter or oxidize hydrocarbons, carbon monoxide, or unburned fuel and oil. Referring to SCR, first, a dosator injects a reductant into the exhaust stream. This reductant may be urea, diesel exhaust fluid (DEF), AdBlue®, urea in water (UWS), urea water solution (e.g., AUS32), or another similar fluid. After injection, the reductant can break down into NH3. This mixture then passes through an SCR catalyst element, which, when at a certain temperature, converts harmful NOx into NH3. x This causes a reaction in the mixture that converts the particulates into pure nitrogen and water. During operation, the undecomposed reductant and unreacted ammonia are stored within the catalytic element (e.g., the SCR catalytic element) and are converted into exhaust products (e.g., NO x It may react chemically with particles.

[0046] The amount of reductant injected into an aftertreatment system (e.g., each flow path in a multi-flow path aftertreatment system) is based, at least in part, on an estimated exhaust gas mass flow rate. The mass flow rate can be estimated based on pressure data captured / sensed / measured by at least one pressure sensor in the aftertreatment system. However, if there are limitations in the aftertreatment system, the estimated mass flow rate may be inaccurate. For example, certain system configurations may respond to a higher estimated mass flow rate with higher reductant dosing (e.g., increasing the rate or duration of reductant dosing) and a lower estimated mass flow rate with lower reductant dosing (e.g., decreasing the rate or duration of reductant dosing). Due to the inaccurate mass flow rate estimation, these system configurations may overdose in at least one flow path, resulting in ammonia slip, or underdose in at least one flow path, resulting in NO. x This can result in slippage. Other factors affected by inaccurate mass flow estimation include, but are not limited to, early or delayed triggering of catalyst regeneration, insufficient regeneration control (e.g., hydrocarbon over-dosing or under-dosing), or overloading of at least one of the flow paths (e.g., soot and deposit loading), to name a few. Accordingly, the systems and methods discussed herein may, for example, estimate the flow split (e.g., mass flow) between the flow paths of an aftertreatment system, calculate a correction / adjustment factor for adjusting the estimated flow split, and perform features and operations to adjust at least one of the reductant dosing, hydrocarbon dosing, or soot loading estimation according to the adjusted flow split.

[0047] Referring now to FIG. 1 , a schematic diagram of a system 10 having a controller 100 is shown, according to an exemplary embodiment. The system 10 includes an internal combustion engine 20 (hereinafter referred to as the “engine”) coupled to an exhaust aftertreatment system 22 in exhaust gas receiving communication with the engine. As shown, the exhaust aftertreatment system 22 is comprised of multiple flow paths (e.g., a first flow path 22A and a second flow path 22B), each flow path including one or more respective components of the exhaust aftertreatment system. While two flow paths are shown and described herein for illustrative purposes, the exhaust aftertreatment system 22 may include three or more flow paths comprising additional components of the exhaust aftertreatment system 22. The controller 100 is coupled to or in communication with the system 10 along with an operator input / output (I / O) device 120. The system 10 may be embodied within a vehicle. Vehicles may include on-road or off-road vehicles, including, but not limited to, linehaul trucks, mid-range trucks (e.g., pickup trucks), automobiles, boats, tanks, airplanes, locomotives, mining equipment, and any other type of vehicle. Vehicles may include a transmission, a fuel delivery system, one or more additional vehicle subsystems, etc. In this regard, vehicles may include additional, fewer, and / or different components / systems, and thus, it is intended that the principles, methods, systems, apparatus, processes, etc. of the present disclosure be applicable to any other vehicle configuration. It should also be understood that the principles of the present disclosure should not be construed as limited to vehicles; rather, the present disclosure is also applicable to stationary pieces of equipment, such as generators or generating sets.

[0048] Engine 20 may be a compression-ignition internal combustion engine that utilizes diesel fuel. In various other embodiments, engine 20 may be configured as any other type of engine (e.g., spark-ignition) that utilizes any type of fuel (e.g., gasoline, natural gas, etc.). In some embodiments, the vehicle may be another type of vehicle, such as a hybrid vehicle that includes one or more electric motors, a fuel cell vehicle, etc. Thus, while engine 20 is configured herein as a diesel-powered internal combustion engine, other embodiments are considered within the scope of the present disclosure.

[0049] Within the internal combustion engine 20, air from the atmosphere is combined with fuel and combusted to power the engine. The combustion of fuel and air within the compression chamber of the engine 20 produces exhaust gases that are operatively discharged to an exhaust manifold (not shown) and an aftertreatment system 22.

[0050] Each flow path (e.g., first flow path 22A and second flow path 22B) of exhaust aftertreatment system 22 includes a diesel oxidation catalyst (DOC) member 30, a diesel particulate filter (DPF) member 40, a selective catalytic reduction (SCR) system 52 having an SCR catalyst member 50, and an ammonia oxidation (AMOx) catalyst member 60. First flow path 22A includes DOC member 30A, DPF member 40A, an SCR system 52A having a first SCR catalyst member 50A, and AMOx catalyst member 60A. Second flow path 22B includes DOC member 30B, DPF member 40B, an SCR system 52B having a second SCR catalyst member 50B, and AMOx catalyst member 60B. For simplicity, the components of each flow path described herein may be generally labeled, for example, as the DOC member 30, DPF member 40, SCR system 52 with respective SCR catalyst member 50, and AMOx catalyst member 60 associated with each first flow path 22A or second flow path 22B.

[0051] The exhaust aftertreatment system 22 further includes an exhaust gas recirculation (EGR) system 70. The SCR systems 52A and 52B of each flow path further include a reductant delivery system having a diesel exhaust fluid (DEF) source 54A-B (e.g., a flow path's DEF source 54) that supplies DEF to DEF dispensers 56A-B (e.g., collectively referred to as dispensers 56 for the first flow path 22A and the second flow path 22B) via DEF lines 58A-B, respectively.

[0052] In an exhaust flow direction indicated by directional arrow 29, exhaust gas flows from the engine 20 into the inlet pipe 24 of the exhaust aftertreatment system 22. From the inlet pipe 24, the exhaust gas flows into the DOC element 30 in a first flow path 22A, exits the DOC element 30, and enters a first section of the exhaust pipe 28A. The exhaust gas flows into the DPF element 40 through the first section of the exhaust pipe 28A, exits the DPF element 40, and enters a second section of the exhaust pipe 28B. The exhaust gas flows into the SCR catalyst element 50 through the second section of the exhaust pipe 28B, and exits the SCR catalyst element 50 and enters a third section of the exhaust pipe 28C. As the exhaust gas flows through the second section of the exhaust pipe 28B, DEF (reductant) is periodically dosed by a DEF (or reductant) doser 56. Thus, the second section of the exhaust pipe 28B functions as a decomposition chamber or tube to promote the decomposition of DEF into ammonia. The exhaust gases enter the AMOx catalyst element 60 through the third section of exhaust line 28C, exit the AMOx catalyst element 60, and enter outlet line 26, after which the exhaust gases are discharged from the aftertreatment system 22. Similarly, in the second flow path 22B, the exhaust gases enter outlet line 26 through lines 28D-28F, which pass through various components within second flow path 22B.

[0053] Based on the above, in the illustrated embodiment, the DOC member 30 (e.g., DOC member 30A or DOC member 30B) is positioned upstream of the DPF member 40 (e.g., DPF member 40A or DPF member 40B) and the SCR catalyst member 50 (e.g., SCR catalyst member 50A or SCR catalyst member 50B), and the SCR catalyst member 50 (e.g., SCR catalyst member 50A or SCR catalyst member 50B) is positioned downstream of the DPF member 40 (e.g., DPF member 40A or DPF member 40B) and upstream of the AMOx catalyst member 60 (e.g., AMOx catalyst member 60A or AMOx catalyst member 60B). However, in alternative embodiments, other arrangements of the components of the exhaust aftertreatment system 22 are possible. Furthermore, for simplicity, the components of one flow path of the exhaust aftertreatment system 22 may be similar to another flow path. Alternatively, one or more components or arrangement of components in the first flow path 22A may be different from that in the second flow path 22B.

[0054] The DOC element 30 may be configured to have any number of different types of flow-through designs. The DOC element 30 may be configured to oxidize at least a portion of the particulate matter in the exhaust (e.g., the soluble organic fraction of soot) and reduce unburned hydrocarbons and CO in the exhaust to compounds that are not harmful to the environment. For example, the DOC element 30 may be configured to reduce the concentration of hydrocarbons and CO in the exhaust to meet required emission standards for those components of the exhaust. An indirect consequence of the oxidation capability of the DOC element 30 is its ability to oxidize NO to NO2. In this way, the level of NO2 exiting the DOC element 30 is equal to the NO2 in the exhaust produced by the engine 20 in addition to the NO2 converted from NO by the DOC element 30.

[0055] In addition to treating hydrocarbon and CO concentrations in the exhaust, the DOC member 30 can also be used for the controlled regeneration of the DPF member 40, SCR catalyst member 50, and AMOx catalyst member 60. This can be achieved by injection or dosing of unburned HCs into the exhaust upstream of the DOC member 30. Upon contact with the DOC member 30, the unburned HCs undergo an exothermic oxidation reaction that results in an increase in the temperature of the exhaust gas exiting the DOC member 30 and subsequently entering the DPF member 40, SCR catalyst member 50, and / or AMOx catalyst member 60. The amount of unburned HCs added to the exhaust is selected to achieve a desired temperature increase or target controlled regeneration temperature.

[0056] The DPF element 40 may be any of a variety of flow-through designs and is configured to reduce particulate matter concentrations (e.g., soot and ash) in the exhaust to meet required emission standards. The DPF element 40 traps particulate matter and other components and, therefore, may be periodically regenerated to burn the trapped components. Additionally, the DPF element 40 may be configured to oxidize NO to form NO2 independently of the DOC element 30.

[0057] As described above, the SCR system 52 includes a reductant supply system. The reductant supply system includes a reductant (e.g., DEF) source 54, a pump (not shown), and a dosator 56 (sometimes referred to as a supply mechanism 56). The reductant source 54 may be a container or tank capable of holding a reductant, such as ammonia (NH), DEF (e.g., urea), or diesel fuel. The reductant source 54 is in reductant supply communication with a pump configured to pump the reductant from the reductant source 54 through a reductant delivery line 58 to the delivery mechanism 56. The delivery mechanism 56 is disposed upstream of the SCR catalyst member 50. The delivery mechanism 56 is selectively controllable to inject the reductant directly into the exhaust stream before it enters the SCR catalyst member 50. As described herein, the controller 100 is configured to control the timing and amount of reductant delivered to the exhaust based, for example, on estimated or calculated mass flow rates across each flow path of the exhaust aftertreatment system 22. The reductant may decompose to produce ammonia. As briefly discussed above, ammonia reacts with NO in the presence of the SCR catalyst member 50. x and responded, NO x to less harmful emissions such as N2 and H2O. x includes NO2 and NO. Both NO2 and NO are reduced to N2 and H2O in the presence of NH3 through various chemical reactions driven by the catalytic elements of the SCR catalyst member.

[0058] In some embodiments, the SCR catalyst member 50 is a vanadium-based catalyst member, and in other embodiments, the SCR catalyst member is a zeolite-based catalyst member, such as a copper-zeolite (Cu-Ze) or iron-zeolite (Fe-Zu) catalyst member. In one exemplary embodiment, the reducing agent is an aqueous urea solution, and the SCR catalyst member 50 is a zeolite-based catalyst member. In other embodiments, the reducing agent includes a first reducing agent and a second reducing agent, where the first reducing agent is urea and the second reducing agent is ammonia.

[0059] The AMOx catalyst member 60 may be any of a variety of flow-through catalyst members configured to react with ammonia to produce primarily nitrogen. As briefly discussed above, the AMOx catalyst member 60 reacts with NO in the exhaust gas to produce x The AMOx catalyst member 60 is configured to remove ammonia that has slipped through or exited the SCR catalyst member 50 without reacting with the SCR catalyst member 60. In certain examples, the aftertreatment system 22 may be operable with or without an AMOx catalyst member. Additionally, although the AMOx catalyst member 60 is shown in FIG. 1 as a separate unit from the SCR system 52, in some embodiments, the AMOx catalyst member may be integrated with the SCR catalyst member (e.g., the AMOx catalyst member and the SCR catalyst member may be located within the same housing). As referred to herein, the SCR catalyst member 50 and the AMOx catalyst member 60 form an SCR and AMOx system.

[0060] The system 10 (e.g., the aftertreatment system 22) includes various sensors. For example, the aftertreatment system 22 may include a NO x The aftertreatment system 22 includes a sensor 12. The aftertreatment system 22 includes a temperature sensor 14. The aftertreatment system 22 includes a pressure sensor 16. The sensors may be strategically positioned throughout the aftertreatment system 22, such as upstream of, at, or downstream of one or more catalysts (e.g., DOC member 30, DPF member 40, SCR catalyst member 50, and / or AMOx catalyst member 60). The sensors may be configured to communicate with the controller 100 and monitor the operating conditions of the system 10. One or more NO x It should be understood that pressure, temperature, and various other sensors (oxygen sensors, exhaust constituent sensors, NH3 sensors) may also be included in the system and located at various locations.

[0061] As shown, one or more pressure sensors 16 may be positioned upstream and downstream of the catalyst member. In this configuration, the pressure sensors 16 measure at least one of the outlet pressure, the inlet pressure, or the pressure at the catalyst member (e.g., a pressure sensor 16 inside the catalyst member (not shown)). For simplicity and purposes of the examples herein, the DPF member 40 may be provided as the catalyst member whose pressure data is monitored to estimate the mass flow rate or flow rate of the exhaust gas. However, the pressure sensors 16 may be positioned upstream, downstream, or on other catalyst members, such as the SCR catalyst member 50, the DOC member 30, or the AMOx catalyst member 60. The pressure data is used by the controller 100 to estimate the mass flow rate.

[0062] Furthermore, more than one NO x Sensors may be positioned upstream and downstream of the catalytic member. In some configurations, one NO x Sensor 12 detects NO from the engine x Measure another NO x The sensor 12 detects the inlet NO x This is because the DOC element 30 / DPF element 40 measures the amount of NO emitted from the engine. x may oxidize some of the NO emitted by the engine. x The amount of the SCR catalyst member 50 inlet NO x This configuration therefore accounts for this potential discrepancy. x The amount of NO downstream of the SCR catalyst member 50 x NO downstream of the sensor 12 and / or the AMOx catalyst member 60 x It may be measured by the sensor 12. x Sensor 12 (in some embodiments, NO x The sensor 12 is positioned downstream of the SCR catalyst member 50 and measures NO in the exhaust downstream of the SCR catalyst member (e.g., exiting the SCR catalyst member). x The device is configured to detect the concentration of NO. x Measurements from the sensor 12 (e.g., measured NOx data) is the NO flow through each flow path of the aftertreatment system 22 x Used by the controller 100 to determine the conversion efficiency. x The conversion efficiency is determined by the NO reduction across one or more components of the aftertreatment system 22. x Corresponding to the amount of NO x The sensor 12 is shown at the outlet of the engine 20, x A sensor 12 may be provided in each flow path upstream of the respective DOC element 30 or DPF element 40 .

[0063] Temperature sensors 14 are associated with one or more catalyst members and are strategically positioned to detect the temperature of the exhaust entering the DOC member 30 (e.g., the temperature of the exhaust conduit upstream of the catalyst member), the temperature of the exhaust exiting the DOC member 30 and entering another catalyst member (e.g., the temperature of the exhaust conduit downstream of the catalyst member), and the temperature of the exhaust exiting the DPF member 40 before DEF is administered by the dosing device 56. In some embodiments, at least one temperature sensor 14 may be configured as part of the catalyst member itself, thereby directly measuring the bed temperature of the catalyst member.

[0064] The EGR system 70 is configured to recirculate exhaust gas into the intake manifold of the engine 20 for use in combustion. The EGR system 70 includes an EGR cooler 74 and an EGR valve 76. In some applications, the EGR cooler 74 may be, for example, an air-to-air and / or liquid (e.g., coolant)-to-air (e.g., exhaust) heat exchanger. The EGR cooler 74 is configured to remove heat from the exhaust gas before it is reintroduced into the intake manifold. Removing heat from the exhaust gas before reintroduction is to prevent, among other reasons, high intake air temperatures that may promote pre-ignition (e.g., engine knock).

[0065] Although the illustrated exhaust aftertreatment system 22 includes a DOC member 30, a DPF member 40, an SCR catalyst member 50, and an AMOx catalyst member 60 arranged at specific positions relative to one another along the exhaust flow path, in other embodiments, the exhaust aftertreatment system may include two or more of any of the DOC member 30, the DPF member 40, the SCR catalyst member 50, and the AMOx catalyst member 60 arranged at any of a variety of positions relative to one another along the exhaust flow path.

[0066] FIG. 1 is also shown to include operator input / output (I / O) device(s) 120. Operator I / O device(s) 120 are communicatively coupled to controller 100 such that information can be exchanged between controller 100 and I / O device(s) 120. Information exchanged between controller 100 and I / O device(s) 120 may relate to one or more components of FIG. 1 or any of the decisions of controller 100 disclosed herein. Operator I / O device(s) 120 enable a vehicle operator (e.g., a passenger, etc.) to communicate with controller 100 and other components of the vehicle such as those shown in FIG. 1. For example, operator I / O device(s) 120 may include an interactive display, a touchscreen device, one or more buttons and switches, a voice command receiver, etc. In some cases, I / O device(s) 120 may be part of the vehicle, including engine 20 and aftertreatment system 22. In some other cases, I / O device(s) 120 may be a remote device accessible by an operator, such as via a client device. In some aspects, the I / O device 120 may be a server that receives data from the vehicle's controller 100 .

[0067] The controller 100 is configured to monitor operations, conditions, or events within the system 10 (e.g., components of the aftertreatment system 22). The controller 100 is configured to at least partially control the operation of the system 10 and associated subsystems, such as the internal combustion engine 20 and the exhaust aftertreatment system 22. Communication between the components may be via any number of wired or wireless connections. For example, a wired connection may include a serial cable, a fiber optic cable, a CAT5 cable, or any other form of wired connection. In contrast, a wireless connection may include the Internet, Wi-Fi, cellular, radio, Bluetooth, etc. In one embodiment, a controller area network ("CAN") bus provides for the exchange of signals, information, and / or data. A CAN bus includes any number of wired and wireless connections. Because the controller 100 is communicatively coupled to the systems and components of FIG. 1 , the controller 100 is configured to receive data from one or more of the components shown in FIG. 1 . For example, the data may include a NO x Data (e.g., NO x Inflow NO from sensor 12 x Amount and No. x NO outflow from sensor 12 x The data may include vehicle operation data (e.g., engine speed, vehicle speed, engine temperature, flow rate, etc.) received via one or more sensors. As another example, the data may include input from operator input / output device 120. As described more fully herein, using this data, controller 100 monitors multi-path aftertreatment system 22 to determine if there are any restrictions causing imbalances in flow splits across the individual paths, and to control reductant slip and NO x Diagnosing imbalances, minimizing slippage, optimizing regenerative control or triggering, etc. The structure, function, or configuration of the controller 100 is further described with respect to FIG.

[0068] FIG. 2 shows an exemplary structure of the controller 100, which includes a processor 102, a memory 103, and at least an engine circuit 105, an ammonia circuit 106, a NO x The processor 102 includes a processing circuit 101 that includes various circuits, including a circuit 107, a flow circuit 108, a compensation circuit 109, a modeling circuit 110, and a regulation circuit 111. The processor 102 may be implemented as an application specific integrated circuit (ASIC), one or more field programmable gate arrays (FPGAs), a digital signal processor (DSP), a group of processing components, or other suitable electronic processing components. The memory 103 (e.g., RAM, ROM, flash memory, hard disk storage, etc.) may store data and / or computer code for facilitating the various processes described herein. The memory 103 may be communicatively coupled to the processor 102 and one or more circuits. In various embodiments, the memory 103 stores data related to the engine circuit 105, the ammonia circuit 106, the NOx circuit 108, the NOx circuit 119, the NOx circuit 120, the NOx circuit 121, the NOx circuit 122, the NOx circuit 123, the NOx circuit 124, the NOx circuit 125, the NOx circuit 126, the NOx circuit 127, the NOx circuit 128, the NOx circuit 129, the NOx circuit 130, the NOx circuit 131, the NOx circuit 132, the NOx circuit 133, the NOx circuit 134, the NOx circuit 135, the NOx circuit 136, the NOx circuit 137, the NOx circuit 138, the NOx circuit 139, the NOx circuit 140, the NOx circuit 141, the NOx circuit 142, the NOx circuit 143, the NOx circuit 144, the NOx circuit 145, the NOx circuit 146, the NOx circuit 147, the NOx circuit 148, the NOx circuit 149, the NO x The controller 100 includes a memory 103, a flow circuit 107, a compensation circuit 108, a correction circuit 109, a modeling circuit 110, and an adjustment circuit 111. The memory 103 is configured to provide computer code or instructions to the processor 102 for executing the processes described with respect to the controller 100 herein. Additionally, the memory 103 may be or include tangible non-transitory volatile or non-volatile memory. Thus, the memory 103 may include database components, object code components, script components, or any other type of information structure to support the various activities and information structures described herein.

[0069] The controller 100 includes a communication interface 104. The communication interface 104 may include any combination of wired and / or wireless interfaces (e.g., jacks, antennas, transmitters, receivers, transceivers, wire terminals) for communicating data with various systems, devices, or networks structured to enable in-vehicle communication (e.g., between vehicle components) and out-of-vehicle communication (e.g., directly with a remote computing system). In this regard, in some embodiments, the communication interface 104 includes a network interface. The network interface is used to establish connections with other computing devices over a network. The network interface includes program logic that facilitates connecting the controller 100 to the network. The network interface includes any combination of wireless network transceivers (e.g., cellular modems, Bluetooth transceivers, Wi-Fi transceivers) and / or wired network transceivers (e.g., Ethernet transceivers). In some configurations, the network interface includes sufficient hardware and machine-readable media to support communication over multiple channels of data communication. Additionally, in some configurations, the network interface includes cryptographic capabilities for establishing secure or relatively secure communication sessions in which data communicated over the sessions is encrypted. For example, with respect to off-vehicle / system communications, the communication interface 104 may include an Ethernet card and port for transmitting and receiving data over an Ethernet-based communication network, and / or a Wi-Fi transceiver for communicating over a wireless communication network. The communication interface 104 may be configured to communicate over a local area network and / or a wide area network (e.g., the Internet) and may use various communication protocols (e.g., IP, LON, Bluetooth, ZigBee, and wireless, cellular, and near field communication).Additionally, the communication interface 104 may operate together or in conjunction with a telematics unit, if included, to communicate with other vehicles in the fleet and / or remote computing systems.

[0070] Controller 100 is configured to receive inputs (e.g., signals, information, data, etc.) from components / systems of system 10 and / or operator I / O devices 120. Thus, controller 100 is configured to at least partially control the components / systems of system 10 and the associated engine 20. Because the components of FIG. 2 may be embodied within a vehicle, controller 100 may be configured as one or more electronic control units (ECUs). Controller 100 may be separate from or included with at least one of a transmission control unit, an exhaust aftertreatment control unit, a powertrain control module, an engine control module, etc. In some cases, controller 100 may be a device remote from the vehicle, such as a remote controller configured to control or communicate with one or more components of system 10.

[0071] In one configuration, the engine circuit 105, the ammonia circuit 106, and the NO xOne or more of the circuit 107, the flow circuit 108, the compensation circuit 109, the modeling circuit 110, or the adjustment circuit 111 may be embodied as a machine or computer-readable medium storing instructions executable by a processor, such as the processor 102, and stored in a memory device, such as the memory 103. As described herein, among other uses, the machine-readable medium facilitates the execution of certain operations to enable the reception and transmission of data. For example, the machine-readable medium may provide instructions (e.g., commands, etc.) for, for example, acquiring data. In this regard, the machine-readable medium may include programmable logic that defines the frequency of data acquisition (or data transmission). The computer-readable medium may include code that may be written in any programming language, including, but not limited to, any conventional procedural programming language, such as Java®, and the “C” programming language or similar programming languages. The computer-readable program code may be executed on one processor or multiple remote processors. In the latter scenario, the remote processors may be connected to each other via any type of network (e.g., a CAN bus, etc.).

[0072] In another configuration, one or more circuits are embodied as a hardware unit such as an electronic control unit. For example, one or more circuits may be embodied as one or more circuit components, including, but not limited to, a processing circuit, a network interface, a peripheral device, an input device, an output device, a sensor, etc. In some embodiments, one or more circuits may take the form of one or more analog circuits, electronic circuits (e.g., integrated circuits (ICs), discrete circuits, system-on-chip (SoC) circuits, microcontrollers, etc.), telecommunications circuits, hybrid circuits, and any other type of “circuit.” For example, the circuits described herein may include one or more transistors, logic gates (e.g., NAND, AND, NOR, OR, XOR, NOT, XNOR, etc.), resistors, multiplexers, registers, capacitors, inductors, diodes, wiring, etc. One or more circuits may also include programmable hardware devices, such as field programmable gate arrays, programmable array logic, programmable logic devices, etc. One or more circuits may be embodied as individual circuits (e.g., engine circuit 105, ammonia circuit 106, NO x The controller 100 may include one or more memory devices for storing instructions executable by the processors of the controller 100 (circuit 107, flow circuit 108, correction circuit 109, modeling circuit 110, and adjustment circuit 111). The one or more memory devices and processors may have the same definitions as provided below with respect to memory 103 and processor 102. In some hardware unit configurations, one or more circuits may be geographically distributed, for example, throughout separate locations within a vehicle. Alternatively, as shown, one or more circuits may be embodied in or within a single unit / housing, shown as controller 100.

[0073] In the illustrated example, the controller 100 controls an engine circuit 105, an ammonia circuit 106, a NO xThe illustrated configuration includes a processing circuit 101 having a circuit 107, a flow circuit 108, a compensation circuit 109, a modeling circuit 110, and a regulation circuit 111. The processing circuit 101 may be structured or configured to execute or implement instructions, commands, and / or control processes described herein with respect to one or more circuits. The illustrated configuration includes an engine circuit 105, an ammonia circuit 106, a NO x The circuit 107, flow circuit 108, compensation circuit 109, modeling circuit 110, and adjustment circuit 111 are represented as instructions in a machine or computer-readable medium. In some embodiments, the instructions may be stored by a memory device. However, as noted above, this illustration is not intended to be limiting, and the present disclosure is directed to the engine circuit 105, the ammonia circuit 106, the NO x Other embodiments are contemplated in which at least one of circuit 107, flow circuit 108, compensation circuit 109, modeling circuit 110, and adjustment circuit 111, or one or more circuits, is configured as a hardware unit, and all such combinations and variations are intended to fall within the scope of the present disclosure.

[0074] In the illustrated example, the controller 100 includes at least an engine circuit 105 configured to control the engine 20, an ammonia circuit 106 in communication with sensors associated with the SCR catalyst member 50 and / or the AMOx catalyst member 60, and a NO x No. communicating with sensor 12 x a flow circuit 108 in communication with the pressure sensor 16 to estimate the mass flow rate through the aftertreatment system 22; a compensation circuit 109 configured to calculate and apply correction factors to the estimated mass flow rate; a modeling circuit 110 in communication with other circuits and configured to manage models relating to predetermined flow rates and their respective correction factors used by the compensation circuit 109; and a modeling circuit 110 in communication with other circuits and configured to, for example, perform reductant dosing control, hydrocarbon based on the correction factor applied to the estimated mass flow rate. Administration and an adjustment circuit 111 configured to adjust at least one of the control, or the soot load estimation.

[0075] The engine circuit 105 is configured to receive information from a user or operator (e.g., via the operator input / output device 120) and provide instructions to or otherwise control the engine 20. For example, the engine circuit 105 may control the operation or components of the engine, including at least an intake valve for controlling the intake of air or gas, an exhaust valve for releasing exhaust through pipes (e.g., lines 24, 28A-F, 26, etc.), or other components of the engine 20. Thus, the engine circuit 105 may control the torque and / or speed of the engine 20. The engine circuit 105 is configured to receive information related to the engine 20, such as fuel supply, temperature, etc., and the engine circuit 105 may communicate the engine information to one or more other circuits of the controller 100 (e.g., the ammonia circuit 106, the NOx circuit 108, the NOx circuit 109, the NOx circuit 201, the NOx circuit 202, the NOx circuit 203, the NOx circuit 204, the NOx circuit 205, the NOx circuit 206, the NOx circuit 207, the NOx circuit 208, the NOx circuit 209, the NOx circuit 210, the NOx circuit 211, the NOx circuit 212, the NOx circuit 213, the NOx circuit 214, the NOx circuit 215, the NOx circuit 216, the NOx circuit 217, the NOx circuit 218, the NOx circuit 219, the NOx circuit 219, the NOx circuit 220, the NOx circuit 225, the NOx circuit 226, the NOx circuit 227, the NOx circuit 228, the NOx circuit 229, the NOx circuit 229, the NOx circuit 229, the NOx circuit 229, the NOx circuit 229, x circuit 107, flow circuit 108, compensation circuit 109, modeling circuit 110, and adjustment circuit 111) and memory 103.

[0076] The ammonia circuit 106 includes, for example, a dosator 56, a temperature sensor 14, and a NO 3 sensor 16 to determine the amount of ammonia (or reductant) stored in the SCR catalyst member 50. x The ammonia circuit 106 is configured to communicate with the sensor 12. In some cases, the ammonia circuit 106 is configured to control the dosing device 56 to supply or introduce the reductant into the pipeline. In this case, the ammonia circuit 106 is configured to determine the reductant dosing rate, including duration, frequency, and timing. Thus, the ammonia circuit 106 controls the dosing rate of the reductant and the NO 2 concentration at the inlet of the SCR catalyst member 50. x and the amount of NO at the outlet of the SCR catalyst member 50 x The amount of NO converted through the catalytic component x At least one of the amount of reductant stored in the SCR catalyst member 50 and data from one or more other circuits, such as the amount of reductant in the SCR catalyst member 50, and / or the mass flow rates in the respective flow paths, can be used to determine the amount of reductant stored in the SCR catalyst member 50.

[0077] NO x Circuit 107 is NO x coupled to the sensor 12, x Communicate with sensor 12 and NO x The controller 100 provides information about the level to other circuits and components of the memory 103. x The sensor is a virtual NO x Sensor or physical No. x It may be a sensor. x Circuit 107 receives NO in addition to other sensor data. x The raw data received from the sensor 12 is processed to obtain the x Information indicative of the level may be provided to other circuitry in the controller 100 and components in the memory 103 .

[0078] The flow circuitry 108 is coupled to and communicates with the pressure sensor 16 to provide information regarding the magnitude of pressure or other pressure data to other circuits and components of the memory 103 of the controller 100. The one or more pressure sensors may be virtual pressure sensors or physical pressure sensors. The flow circuitry 108 may process raw data received from the pressure sensor 16, in addition to other sensor data, to provide information indicative of pressure levels to other circuits and components of the memory 103 of the controller 100. Using the pressure data, the flow circuitry 108 is configured to estimate, for example, mass flow rate at a location corresponding to the pressure sensor 16.

[0079] The correction circuit 109 is x Circuit 107 (e.g., NO xThe compensation circuit 109 is configured to communicate with other circuits, including receiving data from at least one of the flow circuit 108 (e.g., pressure data or mass flow data) or the aftertreatment system 22 (e.g., pressure data or mass flow data). The compensation circuit 109 is configured to calculate a compensation factor (e.g., sometimes referred to as an adjustment factor) to adjust the estimated mass flow rate estimated based on the pressure data. For example, the compensation circuit 109 is configured to receive estimates of mass flow rates across individual flow paths of the aftertreatment system 22. The compensation circuit 109 is configured to identify an imbalanced flow split due to a restriction when the total estimated mass flow rate across the flow paths is not within the range of engine exhaust mass flow rates. If there is an imbalance or inaccuracy in the estimated mass flow rate, the compensation circuit 109 is configured to calculate a compensation factor to calibrate or diagnose the estimated mass flow rate using the techniques and operations described herein. In various embodiments, the compensation circuit 109 is configured to calculate a compensation factor to adjust the estimated mass flow rate due to SCR deposits (e.g., whether a regeneration is performed), a newly installed system, and accumulated soot loading. imbalance It is configured to take into account flow splitting.

[0080] The modeling circuit 110 is configured to manage models representing predetermined flow splits of the aftertreatment system 22. The models may be stored in the memory 103 or a remote database. The modeling circuit 110 is configured to retrieve the models from the memory 103 or the remote database. The modeling circuit 110 is configured to modify or adjust the models given any updated information from the operator I / O device 120. The flow split associated with each model may be predefined, such as 50-50 (e.g., 50% of the engine exhaust mass flow rate over the first flow path 22A and 50% of the exhaust mass flow rate over the second flow path 22B), 65-35 (e.g., 65% over the first flow path 22A and 35% over the second flow path 22B), 55-45 (e.g., 55% over the first flow path 22A and 45% over the second flow path 22B), etc. The correction factor may be a multiplier, percentage, or amount of mass flow rate to increase or decrease the estimated mass flow rate for at least one of the flow paths based on the flow split estimate. The modeling circuit 110 is configured to compare pressure data representing the estimated flow split (e.g., catalyst out pressure or pressure differential across the catalyst member) with various models over time. The modeling circuit 110 is configured to select at least one of the models having a predetermined flow split similar to the estimated flow split. The modeling circuit 110 uses the selected model to adjust the estimated mass flow rate. was The correction circuit 109 is configured to communicate or provide the correction coefficients of the model to the correction circuit 109 .

[0081] The regulation circuit 111 includes an ammonia circuit 106, a NO x The regulation circuit 111 is configured to communicate with other circuits, including the flow circuit 107, the flow circuit 108, the compensation circuit 109, etc. The regulation circuit 111 communicates with the other circuits to x Conversion efficiency, mass flow estimate, amount of stored reductant (e.g., ammonia), NO produced by the engine x , NO in each flow path xThe controller 100 obtains information including at least one of the amount of exhaust by-products traversing the flow path of the aftertreatment system 22, a correction factor, etc. In some cases, the adjustment circuit 111 communicates directly with components of the system, including sensors, the dosator 56, or others. Using information obtained from the system, the adjustment circuit 111 is configured to adjust at least one of the estimated mass flow rate, the reductant dosing rate, the hydrocarbon injection (e.g., regeneration) timing, or the soot loading estimation by applying a correction factor. The adjustment to the dosing rate, the regeneration timing, or the soot loading estimation is based at least in part on the adjusted estimated mass flow rate, which represents the amount of exhaust by-products traversing the flow path of the aftertreatment system 22. As described herein, one or more circuits of the controller 100 are configured to detect and diagnose imbalances in the aftertreatment system 22.

[0082] Referring to FIG. 3, an exemplary graph 300 illustrating the correlation between mass flow split error and the difference in restriction between flow paths is shown. The x-axis can represent the difference in restriction between flow paths (e.g., the percentage of restriction of one flow path compared to another, or the tailpipe pressure drop delta at a rated flow rate), and the y-axis can represent the level of error in the mass flow split ratio. For example, in some systems, there may be a restriction at the tailpipe outlet of the system. In such systems, an increase in the difference in restriction between flow paths (e.g., one flow path has more restriction than the other) can lead to more error in the flow split ratio (e.g., error in the estimation of mass flow rates between flow paths). As shown, the increase in error (e.g., an increase in delta value from zero) may be proportional to an increase in the difference in restriction (e.g., an increase in the flow path tailpipe pressure drop delta). The increase in error represents a decrease in the accuracy of the determined mass flow split ratio. In this case, as the value on the y-axis of graph 300 decreases (e.g., accuracy decreases or error increases), more NH3 will slip out of the tailpipe, as shown in connection with FIG. 4.

[0083] Referring to Figure 4, an exemplary graph 400 illustrating the correlation of ammonia slip to flow path restriction difference is shown. The x-axis can represent flow path restriction difference (e.g., tailpipe pressure drop delta at a particular rated flow rate), and the y-axis can represent the difference in the amount of ammonia slip between flow paths (e.g., flow path delta). Higher values ​​on the y-axis represent more ammonia slip occurring from at least one flow path. Furthermore, Figure 4 In such systems described in, due to an increase in the restriction differential, the system may experience an increase in reductant slip. For example, the restriction differential may cause a particular system to overestimate the mass flow rate across at least one of the flow paths. Thus, the system may increase the reductant dosing rate when the estimated mass flow rate does not represent the actual mass flow rate, thereby causing overdosing of the reductant. In some other instances, the restriction differential may cause the system to underestimate the mass flow rate across at least one of the flow paths. In such cases, the system may underdose the flow path and increase the reductant slip rate. x Therefore, the system and method detects an imbalance caused by a restriction in at least one of the flow paths, diagnoses the imbalance, and measures reductant slip or NO2. x The controller 100 is configured to at least minimize the slip. As shown, an increase in ammonia slip is proportional to an increase in the restriction differential (eg, an increase in the tailpipe pressure drop delta per flow path).

[0084] Referring to FIG. 5, an exemplary graph 500 of collected data including pressure signatures or measurements when a restriction is located upstream of the catalyst outlet of the second flow path 22B (e.g., upstream of the pressure sensor 16 at the outlet of the catalyst element) is shown. The y-axis represents a pressure reading (e.g., a delta pressure reading across a particular catalyst element) relative to the x-axis, which represents the total mass flow rate from the engine 20 (e.g., referred to as exhaust mass flow rate). Mass flow rate is measured in actual cubic meters per second (ACMS). In this case, the restriction may be caused by the inlet piping to the aftertreatment system, such as misalignment or an obstruction, or internal to the catalyst element (e.g., soot loading difference between the two flow paths). Due to this restriction, the system may experience a mass flow imbalance, as shown in FIG. 5. For example, the data point labeled 0% in the legend (e.g., the baseline data point) represents the pressure measurement of a balanced system. A balanced system refers to a system with a 50-50 flow split across the flow paths of the aftertreatment system 22. If there is a restriction upstream of pressure sensor 16, the data point for the flow path with a higher mass flow rate (e.g., labeled 60%) will be shown above the equilibrium data point, representing a relatively high pressure measurement. Additionally, the data point for the flow path with a lower mass flow rate (e.g., labeled "low flow path") will be shown below the equilibrium data point, representing a relatively low pressure measurement. In this case, the 60% inlet valve position (e.g., labeled in the legend) In this case, the flow split is 55-45 (or 55% and 45%, respectively), and the 55% of the exhaust mass flow %teeth 45% of the exhaust mass flow traverses the high flow passage, and 45% of the exhaust mass flow traverses the low flow passage. Therefore, such characteristics of the high and low flow passages indicate that a restriction is upstream of the pressure sensor 16. If there is a restriction upstream of the pressure sensor location (e.g., measuring pressure at the outlet of the DPF member 40), the sum of the individual passage mass flow rates will be equal to or approximately the same as the engine exhaust mass flow.

[0085] Valve positions can be adjusted to mimic asymmetry between different tailpipes or inlet pipes within a test cell (e.g., to adjust, manage, or control symmetry between flow paths). Valve positions can be used, for example, to avoid the need to manufacture different tailpipes for each flow path or to find space in a standard test cell size to accommodate different tailpipes. In the example above, a 60% inlet valve position corresponds to maintaining the second flow path (flow path 2) inlet valve (valve 2) in a 60% closed position, while all other valves remain open (0% closed position), resulting in 55% flow in the first flow path (flow path 1) and 45% flow in flow path 2. In some cases, a 90% outlet valve position corresponds to maintaining the flow path 2 outlet valve (valve 4) in a 90% closed position, while all other valves are open (0% closed position), resulting in 60% flow through flow path 1 and 40% flow through flow path 2. A 60% inlet valve position may correspond, for example, to a specific length of additional piping or a pipe bend on the inlet side of flow path 2 compared to flow path 1. Similarly, the 90% on the outlet side corresponds to a certain additional length of tubing or pipe bend on the outlet side of flow path 2 compared to the outlet of flow path 1, and thus may cause a restriction or difference in flow between the first and second flow paths.

[0086] Referring to FIG. 6, an exemplary graph 600 of collected data including pressure signatures or measurements when a restriction is located downstream of the catalyst outlet of the second flow path 22B (e.g., downstream of the pressure sensor 16 at the outlet of the catalyst member) is shown. As shown, similar to FIG. 5, a baseline data point is shown on the graph (e.g., labeled 0% in the legend) to indicate the pressure signature of a balanced system. The x- and y-axes of graph 600 are similar to the x- and y-axes of graph 500. In some cases, the restriction is located downstream of the pressure sensor 16 in the second flow path 22B. As shown, the pressure measurements in the first flow path 22A and the second flow path 22B (e.g., having a 90% outlet valve position (shown in the legend), representing a 60-40 flow split) are above the baseline data point, indicating a restriction is located downstream of the pressure sensor 16. As a result, for the restriction downstream of the pressure sensor 16, the pressure signature collected by the pressure sensor 16 will be higher than the baseline data for both the high flow path and the low flow path (e.g., low as shown in portion 602). flow rate (opposite pressure signatures for the flow path).

[0087] In the case of a restriction upstream of the pressure sensor 16 used to estimate mass flow, the system may not require a correction / adjustment factor to correct / adjust the estimated mass flow. However, if there is a restriction downstream of the pressure sensor 16, the system is configured to identify variables that may contribute to the downstream restriction in order to resolve or diagnose the imbalanced mass flow (e.g., overestimated and / or underestimated mass flow).

[0088] Referring to FIG. 7 , an exemplary schematic process flow diagram of a process 700 for managing mass flow split in a multi-path aftertreatment system using pressure information is shown. The processes, operations, or steps of FIG. 7 may be implemented, operated, or performed by components of system 10, a data processing system, a cloud computing environment, or any other computing device described herein in conjunction with FIGS. 1-6 (e.g., controller 100, I / O device 120, aftertreatment system 22, sensors, etc.). For example, additional or alternative operations of process 700 may be performed by one or more circuits of controller 100. Additionally or alternatively, some operations of process 700 may be performed by a remote device, such as a remote data processing system. Some operations of process 700 may include controller 100 receiving data from a component of aftertreatment system 22, such as one or more sensors, and forwarding the data to a remote device for processing, or vice versa.

[0089] In step 702, the controller 100 (e.g., the flow circuit 108) is configured to estimate a first mass flow rate of exhaust gas in the first flow path 22A. The first mass flow rate of exhaust gas may be estimated based on pressure data from the pressure sensor 16 in the first flow path 22A, such as the catalyst out pressure or a pressure differential across a catalyst member (e.g., the first DPF member).

[0090] In step 704, the controller 100 (e.g., the flow circuit 108) is configured to estimate a second mass flow rate of the exhaust gas in the second flow path 22B. The second mass flow rate of the exhaust gas can be estimated based on pressure data from the pressure sensor 16 in the second flow path 22B, such as the catalyst out pressure or a pressure differential across a catalyst member (e.g., the second DPF member).

[0091] In step 706, the controller 100 (e.g., the flow circuit 108) is configured to calculate an estimated total mass flow rate based on the estimated first mass flow rate and the estimated second mass flow rate. The controller 100 may calculate the estimated total mass flow rate by summing the estimated first mass flow rate and the estimated second mass flow rate. In various embodiments, the controller 100 is configured to calculate the estimated total mass flow rate using other means, operations, or techniques.

[0092] In step 708, the controller 100 (e.g., the flow circuit 108) determines that the estimated total mass flow rate is greater than the engine exhaust mass flow rate. The engine exhaust mass flow rate corresponds to the total mass flow rate at the outlet of the engine 20. In response to determining that the estimated total mass flow rate is greater than the engine exhaust mass flow rate, the controller 100 (e.g., the correction circuit 109) is configured to calculate a correction factor to balance the estimated first mass flow rate and the estimated second mass flow rate. Balancing the estimated first mass flow rate and the estimated second mass flow rate may refer to correcting at least one of the mass flow rates so that the sum of the estimated mass flow rates is at or near the engine exhaust mass flow rate (e.g., within a deviation of 5%, 3%, etc.), or within a predetermined threshold / range of the engine exhaust mass flow rate. mass flow rate Having an estimated total mass flow rate at or around 1 indicates that the estimated mass flow rate for each flow path is accurate.

[0093] In step 710, the controller 100 (e.g., the flow circuit 108 or the correction circuit 109) is configured to use the correction factors to estimate a corrected first mass flow rate of the exhaust gas in the first flow path 22A and a corrected second mass flow rate of the exhaust gas in the second flow path 22B. The controller 100 is configured to apply the correction factor to the estimated mass flow rate of each flow path to increase or decrease the estimated mass flow rate. In some cases, the correction factor indicates a percentage of the engine exhaust mass flow rate received by each of the flow paths. In this case, the controller 100 is configured to apply the correction factor to the engine exhaust mass flow rate to estimate the corrected first mass flow rate and the corrected second mass flow rate based on the ratio.

[0094] In step 712, the controller 100 (e.g., the adjustment circuit 111) is configured to adjust at least one of the reductant dosing, the hydrocarbon dosing, or the soot load estimation based on the corrected first mass flow rate and the corrected second mass flow rate. An increase from the estimated mass flow rate to the corrected mass flow rate can result in at least one of an increase in reductant dosing, an advance in the timing or frequency of hydrocarbon dosing, or an increase in the soot load estimation due to an increase in exhaust by-products in the flow path. A decrease from the estimated mass flow rate to the corrected mass flow rate can result in at least one of a decrease in reductant dosing, a delay in the timing or frequency of hydrocarbon dosing, or a decrease in the soot load estimation due to a decrease in exhaust by-products in the flow path. In various configurations, operations, techniques, or features of the process 700 can be described in further detail in conjunction with FIG. 8.

[0095] Referring to FIG. 8 , an example process flow diagram is shown for performing the example proportional correction process 800 of FIG. 7 in a multi-path aftertreatment system using pressure information. The process, operations, or steps of FIG. 8 may be implemented, operated, or performed by components (e.g., controller 100, I / O device 120, aftertreatment system 22, sensor, etc.) of system 10, a data processing system, a cloud computing environment, or any other computing device described herein in connection with FIGS. 1-7 . For example, additional or alternative operations of process 800 may be performed by one or more circuits of controller 100. Additionally or alternatively, some operations of process 800 may be performed by a remote device, such as a remote data processing system. Some operations of process 800 may include controller 100 receiving data from a component of aftertreatment system 22, such as one or more sensors, and forwarding the data to a remote device for processing, or vice versa.

[0096] Process 800 begins at step 802. For example, in step 802, controller 100 may receive a command or instruction to initiate action to monitor and diagnose unequal flow splits in system 10. Controller 100 receives the command from I / O device 120 or other remote device via communication interface 104. In some cases, controller 100 initiates process 800 in response to receiving an indication (e.g., from another processing device) that there is a restriction in the system, such as a restriction downstream from pressure sensor 16 used to estimate mass flow rate.

[0097] In step 804, the controller 100 (e.g., the flow circuit 108) estimates or calculates the mass flow rate for each flow path (e.g., the first flow path 22A and / or the second flow path 22B) of the aftertreatment system 22. Each flow path includes one or more respective components of the aftertreatment system 22. For each flow path, the flow circuit 108 estimates the mass flow rate based on pressure information associated with the catalyst member (e.g., the DPF member 40 or other catalyst member). The pressure information includes at least one of a catalyst outlet pressure (e.g., the DPF outlet pressure) or a delta pressure (e.g., the pressure differential / difference across the DPF member 40 or the difference between the pressure at the inlet and the pressure at the outlet of the DPF member 40). The flow circuit 108 may use the following equation / formula to estimate the mass flow rate based on the pressure data:

number

number

number

[0098] In some cases, the flow circuit 108 is configured to use the following simplified model to calculate mass flow rate:

number

number

[0099] The flow circuit 108 calculates the density (rho) as follows:

number

[0100] this

number

number

number

number

number

[0101] An acceptable or desired range of flow accuracy (e.g., difference in mass flow rate from one flow path to another) is ±2% or ±3% above or below a minimum mass flow rate (e.g., total engine flow rate of 24 kg / min, 18 kg / min, etc.). In response to reduced accuracy for estimating the flow division between the flow paths, such as due to noise or limitations downstream of one or more sensors 16, the flow circuit 108 is configured to utilize an equation to estimate a correction factor.

[0102] The flow circuit 108 uses the estimated mass flow rates to identify the mass flow rate in one flow path relative to the other flow path, thereby normalizing modeling errors in the mass flow calculation. Based on the above equations, the flow circuit 108 can estimate the mass flow rate in each flow path (e.g., a first mass flow rate of exhaust gas in the first flow path 22A and a second mass flow rate of exhaust gas in the second flow path 22B) based on at least one of the catalyst outlet pressure or pressure differential across the catalyst member. In some embodiments, the flow circuit 108 is configured to estimate the mass flow rates in the system using other equations.

[0103] The flow circuit 108 calculates (e.g., estimated) total mass flow based on the estimated mass flow rates of the flow path. For simplicity, the estimated total mass flow corresponds to the sum of the estimated mass flow rates at a particular time instance or over a time window. In some cases, the flow circuit 108 calculates the estimated total mass flow when the engine exhaust mass flow (e.g., volumetric flow) exceeds a threshold value (e.g., 0.3 ACMS, 0.4 ACMS, 0.5 ACMS, etc.) or when the pressure at the outlet of the engine 20 exceeds a threshold value (e.g., 4 kPa, 6 kPa, 8 kPa, etc.). A higher engine exhaust mass flow rate may reflect a higher delta between the estimated total mass flow rate and the engine exhaust mass flow rate, which can be used to identify inaccuracies in the estimated mass flow rate based on pressure information. The engine exhaust mass flow rate refers to the mass flow measured at the outlet pipe of the engine 20 upstream of the flow path.

[0104] In step 806, the controller 100 (e.g., the flow circuit 108) determines whether the total mass flow rate of the flow paths is greater than or exceeds the engine exhaust mass flow rate. In some cases, the controller 100 determines whether the total mass flow rate of the flow paths is greater than the engine exhaust mass flow rate by at least a predetermined value (e.g., a percentage or a predetermined percentage). If the estimated total mass flow rate is greater than the engine exhaust mass flow rate, the process 800 proceeds to step 810. An estimated total mass flow rate greater than the engine exhaust mass flow rate reflects an unequal flow split due to a restriction downstream of the pressure sensor 16 used to estimate the mass flow rate. In this case, the estimated mass flow rate of at least one flow path is inaccurate. Otherwise, if the estimated total mass flow rate is less than or equal to the engine exhaust mass flow rate, the process 800 proceeds to step 808.

[0105] If the mass flow leaks or slips from certain joints in the aftertreatment system 22, the total mass flow may fall below the engine exhaust mass flow, thereby reducing the total mass flow. In some embodiments, if the total mass flow falls below a predetermined threshold (e.g., less than 80%, 90%, etc., of the expected total mass flow), the controller 100 may send a notification to the operator I / O device 120 or to send a signal to a service technician (e.g., notify a service technician) to check for leaks, etc., at the next maintenance event of the system 10.

[0106] In step 808, the controller 100 (e.g., correction circuit 109) determines that no correction factor is needed for the flow split based on the estimated total mass flow being less than or equal to the engine exhaust mass flow. Having the estimated total mass flow less than or equal to the engine exhaust mass flow reflects either a balanced flow split or an unbalanced flow split using a restriction upstream from the pressure sensor 16 used to estimate the mass flow. Thus, even if the flow split is unbalanced, the estimated mass flow for each flow path is accurately estimated, and the controller 100 (e.g., adjustment circuit 111) can adjust the reductant dosing rate, controlled hydrocarbon injection, and / or soot loading estimation accordingly.

[0107] In step 810, the controller 100 (e.g., the regulation circuit 111) determines whether the SCR catalyst member 50 has been regenerated (e.g., whether regeneration of the SCR catalyst member 50 has occurred or is in the process of being regenerated). If regeneration is not complete, in step 812, the controller 100 (e.g., the regulation circuit 111) triggers or continues regeneration of the SCR catalyst member 50. The regeneration process removes deposits or catalyst-deactivating compounds (e.g., potential restrictions) and restores the SCR catalyst member 50 to a predetermined activity level. The controller 100 initiates the regeneration process because the imbalance may be caused by deposits in the SCR catalyst member 50 of either the first flow path 22A or the second flow path 22B.

[0108] In various embodiments, in response to determining that the estimated total mass flow is greater than the engine exhaust mass flow, the controller 100 initiates hydrocarbon dosing to regenerate at least one of the first SCR catalyst member in the first flow path 22A and / or the second SCR catalyst member in the second flow path 22B before calculating the correction factor. In some cases, the controller 100 receives an indication of whether an individual SCR catalyst member 50 has been regenerated. Accordingly, the controller 100 initiates hydrocarbon dosing to regenerate at least one of the SCR catalyst members 50 that has not been regenerated or is not in the process of being regenerated. In some cases, the controller 100 initiates hydrocarbon dosing as part of the initiation of the process 800, such as at step 802. If regeneration is complete, the process 800 proceeds to step 814.

[0109] In step 814, similar to step 806, the controller 100 (e.g., the flow circuit 108) determines whether the estimated total mass flow rate exceeds the engine exhaust mass flow rate after regeneration. For example, the controller 100 estimates (e.g., calculated similarly to step 804) a third mass flow rate of exhaust gas in the first flow path 22A and a fourth mass flow rate of exhaust gas in the second flow path 22B after regenerating at least one of the SCR catalyst members 50 in each flow path of the aftertreatment system 22. Using the third and fourth mass flow rates, the controller 100 calculates (e.g., a second) estimated total mass flow rate for comparison with the engine exhaust mass flow rate. The estimated total mass flow rate may be similar to the total mass flow rate described above. If the estimated total mass flow rate is still greater than the engine exhaust mass flow rate, the process 800 proceeds to step 818.

[0110] Otherwise, if the estimated total mass flow is less than or equal to the engine exhaust mass flow, process 800 proceeds to step 816. Similar to step 808, in step 816, controller 100 may not apply a correction factor to the estimated flow split because the regeneration event eliminated any imbalance between the flow paths (e.g., imbalance caused by SCR catalyst member 50), thereby making the estimated total mass flow equal to, for example, the engine exhaust mass flow. As described herein, because the restriction occurred downstream of pressure sensor 16, controller 100 (e.g., correction circuit 109) is configured to calculate a correction factor to balance or correct the estimated first mass flow and the estimated second mass flow calculated from the pressure information.

[0111] In step 818, the controller 100 determines whether the system (e.g., the aftertreatment system 22 or at least one of the flowpath or flowpath components of the aftertreatment system 22) has been newly installed. 806 or 814In response to the estimated total mass flow rate exceeding the engine exhaust mass flow rate, associated with at least one of the following, the controller 100 determines whether the system is newly installed. In some cases, the controller 100 determines whether the system is newly installed at the start of the process 800 (step 802). In other cases, the controller 100 determines whether the system is newly installed after completing a regeneration event in step 810. If the system is newly installed, the process 800 proceeds to step 820. Having a newly installed system (e.g., a system with a relatively low engine operating time, such as less than 50 hours, 100 hours, etc.) may indicate that the limitation was caused by original equipment manufacturer (OEM) piping or was not caused by soot or SCR deposition, considering that one or more components of the aftertreatment system 22 were also newly installed. In this case, the newly installed system having a limitation is due to differences in piping within the system. A system that is no longer considered a new system (e.g., the engine operating hours are above a predetermined threshold) may have different restrictions in one flow path from the other due to the accumulation of ash or soot or deposit formation in certain components of the aftertreatment system 22, such as soot accumulation in the DPF member 40 or deposit formation in the SCR catalyst member 50.

[0112] In step 820, the controller 100 (e.g., the correction circuit 109) calculates a correction factor in response to determining that the first flow path 22A or the second flow path 22B has been newly installed. The controller 100 calculates the correction factor for the newly installed system by performing a proportional correction to the estimated mass flow rate based on the catalyst outlet pressure calculated ACMS value. To perform the proportional correction, the process 800 proceeds to step 828.

[0113] In step 828, the controller 100 (e.g., the correction circuit 109) determines a pressure differential value between the first SCR catalyst element in the first flow path 22A and the second SCR catalyst element in the second flow path 22B. The pressure differential value represents the pressure drop across the catalyst element (e.g., the DPF element 40). The controller 100 determines the pressure differential value based on the difference between a first pressure value at the inlet or upstream of the catalyst element and a second pressure value at the outlet or downstream of the catalyst element. The controller 100 determines the first pressure differential value in the first flow path 22A and the second pressure differential value in the second flow path 22B.

[0114] In step 830, the controller 100 (e.g., the correction circuit 109) calculates a correction factor based on the ratio between the two pressure difference values. The ratio between the pressure difference values ​​represents the flow division between the flow paths. For example, based on the ratio between the two flow paths using the pressure difference values, the controller 100 can determine which of the flow paths is a low-flow flow path (e.g., a flow path with a relatively low mass flow rate) and which is a high-flow flow path (e.g., a flow path with a relatively high mass flow rate). The flow path corresponding to the higher pressure difference value can represent a high-flow flow path, and the flow path corresponding to the lower pressure difference value can represent a low-flow flow path. For example, if a restriction downstream of a pressure sensor, such as in a first flow path, is relatively higher compared to a second flow path, the pressure sensor in the first flow path can measure a higher backpressure induced by the higher restriction downstream of the pressure sensor in the first flow path compared to the second flow path. In another example, if there is a relatively higher restriction upstream of the pressure sensor in one flow path compared to another, such as a first flow path compared to a second flow path (e.g., in this case there is no downstream pressure differential), the pressure sensor may sense a higher pressure when there is a higher mass flow rate in the first flow path. However, because the first flow path has relatively more upstream restriction than the second flow path, the mass flow rate in the first flow path is lower than the mass flow rate in the second flow path, and the pressure sensor may sense a lower pressure in the first flow path.

[0115] In various embodiments, the correction factor is a multiplier based on the ratio between the pressure differential values ​​(e.g., 55-45, 60-40, 65-45, etc.). The controller 100 is configured to apply the correction factor to the engine exhaust mass flow rate. Using a 60-40 ratio (or mass flow rate division) as an example, the controller 100 is configured to estimate a corrected mass flow rate for a low-flow flow path by applying a correction factor (e.g., a lower percentage, such as 40%, in this case) to the engine exhaust mass flow rate (e.g., 40% of the engine exhaust mass flow rate). In some cases, the controller 100 is configured to estimate a corrected mass flow rate for a high-flow flow path by applying a correction factor (e.g., a higher percentage, such as 60%, in this case) to the engine exhaust mass flow rate (e.g., 60% of the engine exhaust mass flow rate). Thus, the controller 100 can estimate a corrected mass flow rate for each flow path based on the ratio between the pressure differential values. Operations for calculating and applying correction factors based on the ratio between the pressure differentials can be described in further detail, for example, in conjunction with at least FIG. 8.

[0116] Returning to step 818, the controller 100 may receive or determine that neither the first flow path 22 A nor the second flow path 22 B, nor any components therein, are newly installed. If the system is not newly installed, the process 800 proceeds to step 822.

[0117] In step 822, the controller 100 (e.g., the flow circuit 108) determines whether soot load flow rebalancing has occurred or is true. Soot load flow rebalancing refers to the accumulation of soot over time in the catalyst members (e.g., the first catalyst member in the first flow path 22A and the second catalyst member in the second flow path 22B) that balances the mass flow division. For example, during periods of low soot load, an unequal flow division may exist in the system. Because soot accumulates faster in the high-flow flow paths (e.g., more soot migrates to the high-flow flow paths) and slower in the low-flow flow paths (e.g., less soot migrates to the low-flow flow paths), the high-flow flow paths accumulate a greater soot load compared to the low-flow flow paths. Over time, the soot load causes a restriction in the high-flow flow paths comparable to the existing restriction in the low-flow flow paths, thereby balancing the flow division among the flow paths of the aftertreatment system 22. Therefore, the controller 100 is configured to monitor the flow split and soot load over time to determine whether the flow split is balanced by the accumulation of soot load.

[0118] The controller 100 determines whether a soot load flow rebalancing has occurred after determining that the system is not newly installed in step 818. In some cases, the controller 100 may perform step 806 or 814 In some other cases, the controller 100 determines whether a soot load flow rebalancing occurred after determining that the estimated total mass flow exceeds the engine exhaust mass flow, in connection with at least one of the following: In some other cases, the controller 100 determines whether a soot load flow rebalancing occurred after completing a regeneration event, for example, in step 810.

[0119] If the controller 100 determines that the flow split has been rebalanced due to soot load buildup, the process 800 proceeds to step 824. Otherwise, the process 800 proceeds to step 826. In either case, the controller 100 is configured to calculate a correction factor based on the estimated soot load flow rate (e.g., mass flow rate relative to soot load).

[0120] In step 824, the controller 100 (e.g., the correction circuit 109) calculates a correction factor based on the engine exhaust mass flow rate for each flow path (e.g., half the engine exhaust mass flow rate) and the hypothetical value for each flow path. In this case, the correction factor is a multiplier that, when applied to at least one of the estimated mass flow rates, increases or decreases the estimated mass flow rate to estimate a corrected mass flow rate. The following equation can be used to determine the correction factor:

number

[0121] For example, half of the engine exhaust mass flow represents the desired mass flow rate for each flow path. The virtual values ​​represent estimated mass flow rates for each flow path based on at least one of differential pressure or catalyst out pressure information. The controller 100 calculates the virtual values ​​based on the estimated total mass flow rate and the flow split across the flow paths of the aftertreatment system 22. For example, if the engine exhaust mass flow rate is 50 kg / min, the controller 100 determines that each flow path has a mass flow rate of 25 kg / min for a 50 / 50 flow split. If the estimated total mass flow rate is 55 kg / min, and the first flow path is at 30 kg / min and the second flow path is at 25 kg / min, the controller 100 calculates a correction factor of 25 / 30 = 0.833 for the first flow path and 25 / 25 = 1 for the second flow path. In a further example, if a first flow path corresponds to a mass flow rate of 32 kg / min and a second flow path corresponds to a mass flow rate of 23 kg / min, the controller 100 calculates a correction factor of 25 / 32=0.78 for the first flow path and 25 / 23=1.08 for the second flow path.

[0122] Based on the above-described techniques, the controller 100 is configured to calculate or estimate a first virtual mass flow rate (e.g., a first virtual value) of exhaust gases in the first flow path 22A based on a first pressure differential value across the first DPF element in the first flow path 22A. Further, the controller 100 is configured to estimate a second virtual mass flow rate (e.g., a second virtual value) of exhaust gases in the second flow path 22B based on a second pressure differential value across the second DPF element in the second flow path 22B. Using the respective pressure differential values ​​of the respective flow paths, the controller 100 is configured to calculate a correction factor (e.g., via the equations provided above) based on the engine exhaust mass flow rate and at least one of the estimated first virtual mass flow rate or the estimated second virtual mass flow rate.

[0123] In step 826, the controller 100 (e.g., the correction circuit 109 and / or the modeling circuit 110) is configured to calculate a correction factor based on the matching model if the soot loading did not rebalance the flow. The process 800 proceeds to step 832 to perform a matching model-based correction factor calculation.

[0124] In step 832, the controller 100 (e.g., modeling circuit 110) determines pressure differential values ​​(e.g., first and second pressure differential values) across each particulate filter (e.g., first and second DPF members) over a time window. The time window includes various time intervals representing the frequency for determining the pressure differential values. Examples of time windows and time intervals include a one-minute time window with a one-second time interval, a five-minute time window with a five-second time interval, among others.

[0125] In step 834, the controller 100 (e.g., modeling circuit 110) compares the pressure difference value at each time interval to a set of calibrated tables. The set of calibrated tables includes a plurality of predetermined pressure difference values ​​representing different flow splits of engine exhaust mass flow. The predetermined pressure difference values ​​may be expressed as a ratio of flow path differential pressure values, such as 50-50, 55-45, 60-40, 65-45, 70-30, etc. for a balanced system. Each calibrated table in the set of calibrated tables is assigned a corresponding bucket for scoring the comparison.

[0126] In step 836, during each time interval within the time window, controller 100 (e.g., modeling circuit 110) is configured to increment the score of at least one of the calibrated tables in the set in response to a calculated pressure difference value (e.g., first and second pressure difference values) or a ratio of pressure difference values ​​being equal to or matching a predetermined pressure difference value or a predetermined ratio in such calibrated table. Controller 100 repeats this process for the remainder of the time window, and process 800 proceeds to step 838.

[0127] In step 838, at the end of the time window, the controller 100 (e.g., the correction circuit 109) calculates at least one correction factor for the flow path of the aftertreatment system 22 based on the selected flow rate split corresponding to the highest-scoring calibrated table in the set. For example, based on the comparison, at the end of the time window, the controller 100 collects the scores associated with each of the calibrated tables in the set.

[0128] By comparing the scores of each calibrated table with each other, the controller 100 is configured to select the calibrated table (e.g., bucket) with the highest score. Furthermore, the controller 100 selects the flow rate division corresponding to the calibrated table with the highest score and calculates a correction factor using the selected flow rate division. Similar to the proportional correction, the controller 100 can apply the flow rate division to the engine exhaust mass flow rate to estimate a corrected mass flow rate for at least one of the flow paths (e.g., the high-flow flow path and / or the low-flow flow path). In some configurations, the controller 100 clears the scores or buckets of the calibrated tables, for example, after selecting the calibrated table with the highest score, after selecting the flow rate division, or after calculating the correction factor. The operation for the matching model-based correction factor can be described in further detail in conjunction with at least FIG. 10 .

[0129] As described herein, the controller 100 (e.g., the correction circuit 109) is configured to apply a correction factor to estimate a corrected mass flow rate. The controller 100 (e.g., the adjustment circuit 111) is then configured to adjust at least one of the reductant dosing, the hydrocarbon dosing, or the soot load estimation based on the corrected first mass flow rate and the corrected second mass flow rate. For example, the controller 100 (e.g., the adjustment circuit 111) can decrease the reductant dosing for one of the flow paths having an overestimated mass flow rate (e.g., decrease from the estimated mass flow rate to the corrected mass flow rate). In some cases, the controller 100 can increase the reductant dosing for one of the flow paths having an underestimated mass flow rate (e.g., increase from the estimated mass flow rate to the corrected mass flow rate).

[0130] In various configurations, the controller 100 (e.g., the adjustment circuit 111) is configured to adjust the hydrocarbon dosing (e.g., frequency or timing) based on the corrected mass flow rate. For example, an overestimated mass flow rate may result in an early or premature regeneration event (e.g., a hydrocarbon dosing event). By applying a correction factor to the estimated mass flow rate, the overestimation is corrected, and the controller 100 can initiate a regeneration event based on the corrected mass flow rate of the respective flow path (e.g., relatively less frequently or at a later time compared to when the mass flow rate was overestimated). Similarly, after correcting an underestimated mass flow rate, the controller 100 can advance the timing of the regeneration event or increase the frequency of the regeneration event for the associated flow path with the underestimated mass flow rate.

[0131] Additionally, the controller 100 (e.g., the adjustment circuit 111) corrects the soot loading estimate based on the corrected mass flow rate. For a flow path with an overestimated mass flow rate, the controller 100 may decrease the soot loading estimate in proportion to the decrease from the estimated mass flow rate to the corrected mass flow rate for the flow path. For a flow path with an underestimated mass flow rate, the controller 100 may increase the soot loading estimate in proportion to the increase from the estimated mass flow rate to the corrected mass flow rate for the flow path. While the examples herein include adjustments to reductant dosing, hydrocarbon dosing, and soot loading estimate, the controller 100 is configured to adjust or control other components of the system 10 based on the corrected mass flow rate in at least one flow path.

[0132] FIG. 9 illustrates graphs 902-912 illustrating exemplary operations associated with the delta-pressure-based correction process of FIG. 8 , such as for a newly installed system. Each graph represents a step for performing proportional correction, such as described in conjunction with at least steps 820, 828, and 830 of FIG. 8 . Referring to graph 902, controller 100 (e.g., flow circuit 108) receives catalyst output pressure data from pressure sensor 16 in each of the flow paths, including the low flow path and the high flow path. As shown, the catalyst out pressure readings for both the low flow path (e.g., portion 914) and the high flow path (e.g., labeled 65-35 in the legend) are above the data point representing the balanced flow split (e.g., labeled 50-50 in the legend).

[0133] In graph 904, controller 100 estimates the mass flow rate for each flow path based on the catalyst out pressure data of graph 902. As shown, the exhaust mass flow rate is overestimated for second flow path 22B (e.g., the low flow path labeled "65-35 L2" in the legend) when using the catalyst out pressure data for mass flow rate estimation. Portion 916 includes the estimated mass flow rate for the low flow path (e.g., second flow path 22B in this case), which is above the baseline mass flow rate (e.g., the 50-50 data point).

[0134] Thereafter, in graph 906, the controller 100 estimates the total mass flow rate based on the first flow path 22A and the second flow path 22B (e.g., by adding the respective mass flow rates). The controller 100 determines that the estimated total mass flow rate is greater than the engine exhaust mass flow rate, as shown in portion 918. In this example, the engine exhaust mass flow rate is, for example, the baseline data point labeled "50-50." Because the estimated total mass flow rate is greater than the engine exhaust mass flow rate, indicating that the system is newly installed, the controller 100 determines to perform a proportional correction to correct the mass flow rate estimate for at least one of the flow paths (e.g., the low-flow flow path).

[0135] In graph 908, controller 100 receives an indication that the catalyst member has been cleaned (e.g., assuming the system is newly installed). With respect to the clean catalyst member, controller 100 is configured to determine which of the flow paths is a low-flow flow path or a high-flow flow path based on delta pressure information across the catalyst member (e.g., DPF delta pressure (dp)). For example, controller 100 receives delta pressure information across the catalyst member of each flow path. As shown, controller 100 identifies a high-flow flow path based on the catalyst delta pressure (e.g., labeled "65-35") being above a baseline data point. Furthermore, controller 100 identifies a low-flow flow path based on the catalyst delta pressure (e.g., at portion 920) being below a baseline data point. Thus, controller 100 is configured to identify low-flow and high-flow flow paths using the delta pressure across the catalyst member.

[0136] The controller 100 calculates a ratio between the delta pressures of the high flow path and the low flow path. The ratio between the delta pressures can be used as part of a correction factor. For example, the controller 100 applies the ratio to the engine exhaust mass flow rate. In this case, the ratio is 65% for the high flow path and 35% for the low flow path, estimated based on the delta pressures of the respective catalyst members. The controller 100 calculates a first corrected mass flow rate for the low flow path corresponding to 35% of the engine exhaust mass flow rate and a second corrected mass flow rate for the high flow path corresponding to 65% of the engine exhaust mass flow rate. In some cases, the controller 100 applies a proportional correction to pressure data (e.g., catalyst out pressure) of at least one of the flow paths so that the corrected pressure data can be used to calculate the corrected mass flow rates.

[0137] In various embodiments, the controller 100 is configured to ignore or skip estimating a corrected mass flow rate for the high-flow flow path, for example, because the pressure data for the second flow path 22B may not be affected by a restriction in the low-flow flow path. For simplicity, the controller 100 is configured to correct the mass flow rate estimate for the low-flow flow path without adjusting the estimated mass flow rate for the high-flow flow path if the high-flow flow path is not affected by a restriction. In other cases, the controller 100 is configured to adjust the estimated mass flow rates for both flow paths.

[0138] In graph 910, the controller 100 applies a correction factor to the estimated mass flow rate of the low-flow flow path. In some cases, applying the correction factor may include using a corrected mass flow rate calculated for each flow path. As shown in portion 922, the controller 100 applies the correction factor to the low-flow flow path, thereby correcting / diagnosing an overestimation of the mass flow rate of the low-flow flow path. In some cases, the controller 100 also applies a respective correction factor to the high-flow flow path to adjust the estimated mass flow rate of the second flow path 22B. Compared to graph 904, the corrected mass flow rate of the low-flow flow path is below the baseline data point.

[0139] In graph 912, the controller 100 aggregates or sums the corrected mass flow rates to determine a corrected total mass flow rate. As shown in portion 924, compared to graph 906, the data points representing the corrected total mass flow rate are approximately the same as the data points for the engine exhaust mass flow rate. Thus, the mass flow rate across the flow path represents the engine exhaust mass flow rate input to the aftertreatment system 22.

[0140] 10, a block diagram of an example matching model 1000 associated with at least step 826 of FIG. 8 is shown. The controller 100 (e.g., the correction circuit 109 and / or the modeling circuit 110) is configured to use the matching model 1000 to calculate the correction coefficients, at least when the system is not newly installed and the flow split is not rebalanced by soot loading. The process of the matching model 1000 can be described in conjunction with steps 826 and 832-838 of FIG. 8. In various configurations, the matching model 1000 can be run continuously or periodically (e.g., at predetermined time intervals or based on specific operating events of the engine 20, such as engine ignition, production of exhaust by-products, etc.).

[0141] The matching model 1000 includes an input block 1002 and a flow division calculation block 1004. The input block 1002 includes processes for receiving and aggregating input data. The input data can be used in the flow division calculation block 1004, which includes processes for calculating the flow division of the mass flow rate between the flow paths. The calculated flow division can be monitored within a predetermined time window (e.g., window-based monitoring logic), as described herein in step 1018.

[0142] In step 1006, the controller 100 receives or determines (e.g., total) engine exhaust mass flow from the engine 20. The controller 100 calculates the engine exhaust mass flow based on the sum of fresh air flow at the engine inlet and fuel flow delivered into the combustion chamber by at least one fuel injector. The fresh air flow corresponds to the inlet air flow measured, for example, by a flow sensor or based on the sum of the charge air flow and the EGR flow. The charge flow is calculated using the PV=mRT equation (e.g., the ideal gas law). The EGR flow rate is calculated using the flow rate through the venturi system. In this case, for example, there may be a charge pressure sensor and a venturi pressure sensor within the engine structure. The engine exhaust mass flow rate reflects the desired estimated total exhaust mass flow rate to be divided among the flow paths of the aftertreatment system 22.

[0143] In step 1008, the controller 100 applies a first-order filter to the calculated engine exhaust mass flow rate. The first-order filter may be, for example, a state-updating Kalman filter, among other types of first-order filters such as an alpha-beta filter or a moving average, among others. The controller 100 determines a filtered engine exhaust mass flow rate in response to applying the filter. The equation for the Kalman filter is provided as follows:

number

[0144] In step 1010, the controller 100 determines the volumetric flow rate in cubic meters per second (ACMS) for at least one flow path (e.g., for comparison with pressure information used to estimate mass flow rate in at least one flow path). ACMS can be calculated as follows:

number

[0145] In step 1012, controller 100 reads or retrieves various calibrated tables (e.g., sometimes referred to as models) from memory 103 or a remote database (e.g., calibrated tables similar to those described in FIG. 8). Each calibrated table includes predetermined pressure information (e.g., at least one of catalyst pressure output information or pressure differential information) corresponding to a respective flow split for engine exhaust mass flow. Different pressure information corresponds to different flow splits. For example, a first calibration table may correspond to a 60-40 flow split (e.g., 60% engine exhaust mass flow for the high flow path and 40% engine exhaust mass flow for the low flow path), a second calibration table may correspond to a 65-35 flow split, a third calibration table may correspond to a 70-30 flow split, etc.

[0146] In various configurations, controller 100 selects or obtains at least one set of calibrated tables based on engine exhaust mass flow rates. For example, different engine exhaust mass flow rates result in different pressure readings (e.g., catalyst out pressure data and pressure differential data) for each flow path of aftertreatment system 22. Accordingly, each set of calibrated tables may be configured for a respective engine exhaust mass flow rate. Controller 100 selects at least one of the sets of calibrated tables based, for example, on a comparison between a calculated engine exhaust mass flow rate or ACMS, as described in connection with step 1010, and a predetermined engine exhaust mass flow rate associated with each set of calibrated tables.

[0147] In step 1014, the controller 100 receives sensed / measured catalyst out pressure information for at least one flow path (e.g., first flow path 22A is used as an example) at predetermined operating conditions of the engine 20 and / or aftertreatment system 22 (e.g., fuel injection rate, reductant dosing rate, fresh air flow rate, torque demand, etc.).

[0148] In step 1016, the controller 100 applies a primary filter to the measured catalyst out pressure of the first flow path 22A (or the second flow path 22B). The controller 100 uses the filtered catalyst out pressure information for comparison with predetermined pressure information from a calibrated table (e.g., in one of a set of calibrated tables based on engine exhaust mass flow rate). For example, the controller 100 compares the measured pressure value sensed from at least one of the pressure sensors 16 with the predetermined pressure value in each calibrated table. The controller 100 can identify at least one calibrated table having the predetermined pressure value closest to the measured pressure value. The controller 100 then calculates the catalyst out pressure at each interval within the predetermined time window. block The process of 1002 and 1004 is repeated and step 1018 is configured to monitor a comparison between the measured pressure value and a predetermined pressure value.

[0149] In step 1018, the controller 100 is configured to execute a window-based monitoring technique to monitor comparisons of measured pressure values ​​with model (e.g., predetermined) pressure values ​​performed within a predetermined time window. Within the time window, the controller 100 tracks the number of times that each pair of measured pressure values ​​from the flow paths (e.g., pressure values ​​from the first and second flow paths 22A-B) matches a model pressure value from at least one calibrated table. In response to each match, the controller 100 increments a score or bucket corresponding to the calibrated table with the model pressure value. If the measured pressure value falls between two model pressure values ​​from different calibrated tables, the controller 100 may increment the scores of both calibrated tables.

[0150] At the end of the window, the controller 100 selects the model (e.g., the calibrated table) with the highest score (e.g., highest number of matches). Selecting the calibrated table may correspond to selecting a flow rate split corresponding to the calibrated table. The controller 100 is configured to calculate a correction factor utilizing the selected flow rate split to correct the estimated mass flow rate of the at least one flow path. As described above, the controller 100 may calculate the corrected mass flow rate by applying the correction factor to the estimated mass flow rate or by applying the flow rate split to the engine exhaust mass flow rate to identify mass flow rates across high-flow and low-flow flow paths.

[0151] Referring to FIG. 11, a graph 1100 illustrating a model-based approach related to at least step 826 of FIG. 8 for inlet pipe restriction is shown. Graph 1100 illustrates exemplary cases of measured pressure values ​​(e.g., catalyst out pressure) and estimated / calculated mass flow rates for the first flow path 22A and the second flow path 22B of the aftertreatment system 22. Case 1 corresponds to a balanced system with a 50-50 flow split. Case 2 corresponds to a 57-43 flow split system with an inlet pipe restriction (e.g., a restriction upstream of the pressure sensor 16 used to measure the pressure information). Case 3 corresponds to a 60-40 flow split system with an inlet pipe restriction. As shown, the (e.g., pre-calibrated) lines in graph 1100 represent modeled pressure values ​​versus modeled mass flow rates for a particular calibrated table. Lines 60 and 40 represent a calibrated table with a 60-40 flow split. Lines 57 and 43 represent a calibrated table with a 57-43 flow split. Line 50 represents a 50-50 flow split calibration table or baseline value.

[0152] In Case 2, the controller 100 determines that the data points for the first flow path 22A and the second flow path 22B are aligned with data points in the calibrated table corresponding to a 57-43 flow division. Therefore, the controller 100 may select a 57-43 flow division for calculating a correction factor. In Case 3, the controller 100 may determine that the total mass flow is greater than the engine exhaust mass flow. The controller 100 is configured to correct the estimated mass flow for at least the low-flow flow path (e.g., the second flow path 22B in this case). The correction of the mass flow may be described in connection with FIG. 7. After correcting the estimated mass flow, the controller 100 determines that the data points for the first flow path 22A and the second flow path 22B are aligned with data points in the calibrated table corresponding to a 40-60 outlet flow division table. In some cases, the controller 100 determines that the data points corresponding to the first flow path 22A align with a 60-40 inlet flow division table and selects the flow division without correcting the data points for the second flow path 22B. Thus, the controller 100 may, for example, select a 60-40 flow division for purposes of calculating a correction factor.

[0153] Referring to Figure 12, a graph 1200 illustrating a model-based approach for tailpipe restriction is shown. 1100Similarly, three cases are provided, including Case 1 for a 50-50 flow split, Case 2 for a 57-43 flow split, and Case 3 for a 60-40 flow split. In this case, the imbalance between the 57-43 flow split and the 60-40 flow split is caused by a tailpipe restriction (e.g., a restriction downstream of the pressure sensor 16 used to estimate mass flow). As shown, the pre-calibrated line for the tailpipe restriction differs from the line for the inlet pipe restriction because the location of the restriction affects the pressure measurements and mass flow estimates. In Case 2, the controller 100 determines that the data points for the first flow path 22A align with the calibrated table corresponding to the 57-43 flow split (e.g., a comparison between measured and modeled values). The controller 100 selects the 57-43 flow split to calculate a correction factor. In Case 3, the controller 100 compares the measured data points to the modeled data points and identifies an alignment with the calibrated table corresponding to a 60-40 flow split. Therefore, the controller 100 selects the 60-40 flow split for calculating the correction factor. The controller 100 can interpolate between other tables or models based on other readings from the pressure sensor 16.

[0154] FIG. 13 illustrates exemplary graphs 1302-1308 depicting monitored data for the model-based approach of FIG. 8 matching 50-50 flow split data to respective flow split tables. Graph 1302, among other graphs in FIGS. 14-16, such as graphs 1402, 1502, and 1602, represents predicted flow splits between flow paths in aftertreatment system 22. As shown, controller 100 can match 50-50 flow split data to the 50-50 flow split tables using the model-based approach of FIG. 8. Index 1 in graph 1302 represents or corresponds to the 50-50 flow split table.

[0155] FIG. 14 illustrates exemplary graphs 1402-1408 depicting monitored data for the model-based approach of FIG. 8 matching 40-60 flow split data to respective flow split tables. As shown, controller 100 can match 40-60 flow split data to 40-60 flow split tables using the model-based approach of FIG. 8. Index 5 in graph 1402 represents or corresponds to the 40-60 inlet flow split table. In graph 1404, updates may be paused from time 500 to approximately time 2250 because the temperature or exhaust gas mass flow minimum thresholds have not been met.

[0156] Figure 15 shows exemplary graphs 1502-1508 illustrating monitored data for the model-based approach of Figure 8 for matching 60-40 flow split data to at least one respective flow split table. As shown, controller 100 can use the model-based approach of Figure 8 to match the 60-40 flow split data to at least one of the 55-45 or 60-40 flow split tables. Index 6 in graph 1502 represents or corresponds to the 55-45 outlet flow split table, and index 8 in graph 1502 represents or corresponds to the 60-40 outlet flow split table.

[0157] 16 illustrates exemplary graphs 1602-1608 showing monitored data for the model-based approach of FIG. 8 for matching TC NRTC 50-50 flow split data (e.g., exemplary mockup or test data) to respective flow split tables. As shown, the controller 100 can match the TC NRTC 50-50 flow split data to the 50-50 flow split data using the model-based approach of FIG. 8. Index of graph 1602 1 represents or corresponds to a 50-50 flow rate split table. Figure 13 shows a steady state cycle (e.g., graph 1306), while Figure 16 shows a transient cycle (e.g., graph 1606).

[0158] Now referring to Figure 17, NO x A schematic process flow diagram of another exemplary process 1700 for managing mass flow split in a multi-path aftertreatment system of the engine system of FIG. 1 using measurements is shown. The process, operations, or steps of FIG. 17 may be implemented, operated, or performed by components of system 10, a data processing system, a cloud computing environment, or any other computing device described herein in conjunction with FIGS. 1-16 (e.g., controller 100, I / O device 120, aftertreatment system 22, sensors, etc.). For example, additional or alternative operations of process 1700 may be performed by one or more circuits of controller 100. Additionally or alternatively, some operations of process 1700 may be performed by a remote device, such as a remote data processing system. Some operations of process 1700 may include controller 100 receiving data from components of aftertreatment system 22, such as one or more sensors, and forwarding the data to a remote device for processing, or vice versa.

[0159] In step 1702, the controller (e.g., NO x The circuit 107) is connected to the first NO 2 in the first flow path 22A. x The controller 100 calculates the conversion efficiency by calculating the NO 2 concentration at the inlet of the first flow path 22A or upstream of the first catalyst member (e.g., the first SCR catalyst member). x and the amount / level of NO at the outlet of the first flow path 22A or downstream of the first catalytic member. x First, based on the difference between the amount of NO x Calculate the conversion efficiency.

[0160] In step 1704, the controller (e.g., NO x The circuit 107) is connected to the second NO 2 in the second flow path 22B. x The controller 100 calculates the conversion efficiency by calculating the NO 2 concentration at the inlet of the second flow path 22B or upstream of the second catalyst member (e.g., the second SCR catalyst member). xand the amount of NO at the outlet of the second flow path 22B or downstream of the second catalyst member. x Based on the difference between the amount of NO x Calculate the conversion efficiency.

[0161] In step 1706, the controller (e.g., NO x The circuit 107) is a first NO x Conversion efficiency and second NO x Average NO based on conversion efficiency x Calculate the conversion efficiency (e.g., two NO x In step 1708, the controller (e.g., x The circuit 107) is a first NO x Conversion efficiency and second NO x The controller 100 is configured to calculate the difference between the conversion efficiency of ammonia to NO between the first flow path 22A and the second flow path 22B. x After determining that the ANRs were similar, the mean NO x The conversion efficiency and the difference are calculated. Having similar ANR means that the flow paths have similar NO x Therefore, the average NO x If the conversion efficiency falls below a threshold, or if the first NO x Conversion efficiency and second NO x If the difference in conversion efficiency is greater than a threshold, this indicates a tailpipe limitation.

[0162] In step 1710, the average NO x The conversion efficiency is less than a first threshold value or the first NO x Conversion efficiency and second NO x In response to determining that the difference between the conversion efficiency and the estimated first mass flow rate is greater than the first threshold, the controller (e.g., the correction circuit 109) is configured to calculate an adjustment factor to balance the estimated first mass flow rate and the estimated second mass flow rate. The adjustment factor is a function of the low NO x Conversion efficiency can be calculated based on the ANR of the flow path. For example, low NO xIf the ANR of the conversion efficiency channel is greater than (or equal to) the threshold, this indicates a low NO x This indicates that there is ammonia slip from the conversion flow path. x If the ANR of the conversion efficiency channel is below the threshold, this indicates a low NO x Conversion efficiency of NO from the flow path x The adjustment factor indicates whether ammonia slip is present or NO x It can be predefined based on whether slip is present.

[0163] In step 1712, the controller (e.g., the flow circuit 108 or the correction circuit 109) is configured to estimate an adjusted first mass flow rate of the exhaust gas in the first flow path 22A and an adjusted second mass flow rate of the exhaust gas in the second flow path 22B using the adjustment factors. If there is an indication of ammonia slip, the controller 100 estimates the adjusted mass flow rates by reducing the estimated mass flow rates. x If there is an indication of slippage, the controller 100 estimates the adjusted mass flow rate by increasing the estimated mass flow rate.

[0164] In step 1714, the controller (e.g., adjustment circuit 111) is configured to adjust at least one of the reductant dosing, the hydrocarbon dosing, or the soot loading estimation based on the adjusted first mass flow rate and the adjusted second mass flow rate. In various embodiments, operations, techniques, or features of process 1700 may be described in further detail in conjunction with FIG.

[0165] 18 , a process flow diagram of an exemplary process 1800 for managing mass flow splitting in a multi-path aftertreatment system associated with FIG. 17 is shown, as will be described in further detail. The processes, operations, or steps of FIG. 18 may be implemented, operated, or performed by components (e.g., controller 100, I / O device 120, aftertreatment system 22, sensors, etc.) of system 10, a data processing system, a cloud computing environment, or any other computing device described herein in connection with FIGS. 1-17 . For example, additional or alternative operations of process 1800 may be performed by one or more circuits of controller 100. Additionally or alternatively, some operations of process 1800 may be performed by a remote device, such as a remote data processing system. Some operations of process 1800 may include controller 100 receiving data from components of aftertreatment system 22, such as one or more sensors, and forwarding the data to a remote device for processing, or vice versa.

[0166] Process 1800 begins at step 1802. Process 1800 may be performed before or after determining that the flow split is unbalanced. Process 1800 may be performed in addition to or instead of process 800 of FIG. 8. In step 1802, controller 100 is configured to initiate a cleaning operation of a catalyst member (e.g., DPF member 40, SCR catalyst member 50, etc.). After the catalyst member is cleaned (e.g., to remove soot loading or deposit accumulation factors for an unbalanced system), controller 100 proceeds to step 1804.

[0167] In step 1804, the controller 100 calculates the average ammonia vs. NO x Determine whether the ANR is similar between flow paths. The ANR can be measured in moles, where 1.1 moles is, for example, NO xThis indicates that there is 1.1 times the amount of ammonia (e.g., reducing agent) compared to the ANR. Having an ANR of about 1 (e.g., 0.9-1.1, 0.95-1.05, 0.98-1.02, etc.) indicates that there is 1.1 times the amount of reducing agent and NO in the tailpipe. x is below a desired level (e.g., if the mass flow estimation is accurate), reducing agent vs. NO x If the ANR between the flow paths is similar, process 1800 proceeds to step 1806. Otherwise, process 1800 remains at step 1804, where controller 100 determines whether the ANR between the flow paths is similar for another time interval.

[0168] In various embodiments, in a system without tailpipe limitations, having similar ANR between flow paths can be achieved by achieving an average conversion efficiency (e.g., NO between flow paths) above a conversion efficiency threshold. x Furthermore, in a system without a restriction in the tailpipe, having similar ANR between the flow paths results in the difference in conversion efficiency between the first flow path 22A and the second flow path 22B being below another threshold. However, as described herein, if the ANR is similar between the flow paths and at least one of the average conversion efficiency or the difference between the conversion efficiencies exceeds a desired level (e.g., in step 1808), the controller 100 is configured to determine that a restriction exists in the tailpipe causing an inaccurate estimation of mass flow rate. An inaccurate estimation of mass flow rate results in an erroneous dosing rate of the reductant. An erroneous dosing rate can lead to NO x slip or reductant slip (e.g., ammonia slip). x or reductant slip occurs when NO in the tailpipe exceeds the desired level x Thus, as described herein, the conversion efficiency of the flow path can be used to determine if there is a restriction in the tailpipe and to calculate an adjustment factor to correct / adjust the estimated mass flow rate and / or the reductant dosing rate.

[0169] In some cases, the system 10 may be implemented or configured with an ammonia sensor (not shown). The ammonia sensor may be located downstream of the catalyst member (e.g., DPF member 40, SCR catalyst member 50, etc.) in each flow path. The ammonia sensor may also be located in the tailpipe of each flow path. In this case, with similar ANR between the flow paths, the controller 100 may detect ammonia and / or NO between each flow path. x The difference in the level of (e.g., ammonia sensor or NO x If the difference between the flow paths is greater than or exceeds a threshold, the controller 100 determines that there is a restriction in the tailpipe in at least one of the flow paths that would lead to an erroneous mass flow estimation. x Similar to using conversion efficiency, the controller 100 may also use, for example, the level of reductant or NO to correct the estimated mass flow rate or dosage rate. x The slip can be used to calculate an adjustment factor.

[0170] In step 1806, the controller 100 (e.g., NO x The circuit 107) is configured to provide an average NO between the first flow path 22A and the second flow path 22B. x To calculate the average, the controller 100 calculates / computes the conversion efficiency (CE) of the first NO 2 in the first flow path 22A. x Conversion efficiency and second NO in second flow path 22B x The conversion efficiency of each flow path is calculated. x The conversion efficiency is calculated by the ratio of NO x The amount of NO at the outlet of the flow channel x The control device 100 determines the difference between the amount of the first NO x Purification rate and second NO x Based on purification rate and average NO x Furthermore, the controller 100 calculates the NO purification rate between the flow paths. x The difference in conversion efficiency is calculated.

[0171] In step 1808, the controller 100 (e.g., NO x The circuit 107) determines whether the average conversion efficiency is less than a threshold (e.g., a first threshold) or is NO. x Determine whether the difference between the conversion efficiencies is greater than a threshold. For example, NO x The threshold for the difference in conversion rate may be 10%, 15%, 20%, etc. If at least one of the conditions is true, process 1800 proceeds to step 1810. Otherwise, if both conditions are false, process 1800 proceeds to step 1832.

[0172] In step 1810, the controller 100 receives a sample estimated mass flow rate for each flow path for corrective adjustment (e.g., corrected / adjusted using an adjustment factor). The controller 100 (e.g., the flow circuit 108) can estimate the mass flow rate for each flow path based on pressure information (e.g., catalyst out pressure or pressure differential). In some cases, the controller 100 receives the estimated mass flow rate from a remote computing system that has processed the pressure data or other data related to mass flow rate.

[0173] In various configurations, the controller 100 (e.g., x The circuit 107) calculates the first NO of the first flow path 22A. x The conversion efficiency of the second NO flow path 22B is calculated as x Based on this comparison, the controller 100 determines which flow path has the lowest NO x Determine the conversion efficiency. Lower NO x A flow path with a high conversion efficiency is considered to be a low conversion efficiency flow path (e.g., low NO x Additionally, the controller 100 determines the ANR of the low conversion efficiency flow path.

[0174] In step 1812, the controller 100 (e.g., NO xCircuit 107 compares the ANR of the low conversion efficiency flow path to a predetermined threshold (e.g., a second threshold). This threshold may be predefined by an administrator of system 10 or configured via operator I / O device 120. The threshold may be predefined as 1 mol, 1.1 mol, 0.9 mol, among others. For example, an ANR of less than 0.9 for a low conversion efficiency flow path (e.g., less than 80% conversion efficiency) indicates a high NOx content in the tailpipe. x In another example, an ANR of 1.3 for a low conversion efficiency flow path (e.g., less than 85%-90% conversion efficiency) can indicate NH slip in the tailpipe. Comparing the ANR of the low conversion efficiency flow path to a threshold value can indicate NO x For example, if the ANR of the low conversion efficiency flow path is greater than (or, in some cases, equal to) a threshold value, the controller 100 determines whether the percentage of ammonia in the ANR is greater than or equal to NO. x If the ANR is less than the threshold, the controller 100 determines that the percentage of ammonia in the ANR is greater than the percentage of NO. x Low conversion efficiency due to lower ratio of NO from the flow path x It is determined that there is a slip. NO from the low conversion efficiency flow path x In response to identifying or determining that a slip exists, process 1800 proceeds to step 1816 .

[0175] In step 1814, the controller 100 (e.g., the adjustment circuit 111) is configured to adjust the reductant dosing rate based on ammonia slip from the low conversion efficiency flow path. For example, the controller 100 can decrease the dosing rate due to ammonia slip (e.g., caused by overdosing of reductant). In this case, the overdosing of reductant is due to an overestimation of the mass flow rate. The controller 100 can decrease the estimated mass flow rate (e.g., referred to as the adjusted mass flow rate) of the low conversion efficiency flow path using a predetermined adjustment factor. For example, a correction factor (e.g., a correction multiplication factor) of 1.1 can be initially used to increase the mass flow rate, or a correction factor of 0.9 can be initially used to decrease the mass flow rate. In response to this adjustment, the controller 100 decreases the reductant dosing rate in proportion to the decrease in the estimated mass flow rate. In some cases, the controller 100 is configured to decrease the dosing rate by a predetermined amount in response to the ammonia slip. The predetermined amount can be configured by an administrator of the system 10, such as decreasing the dosing rate by 10%, 20%, 30%, etc., or by a predetermined rate. In this scenario, the dosage rates or estimated mass flow rates of other flow paths different from the low conversion efficiency flow path may not be adjusted because the erroneous estimate is in the low conversion efficiency flow path.

[0176] In step 1816, in response to determining that the ANR of the low conversion efficiency flow path is below a threshold, the controller 100 is configured to adjust the dosing rate of the reductant by increasing the dosing rate. Having a low ANR (e.g., an ANR below a threshold) for the low conversion efficiency flow path indicates that NO is being delivered to the low conversion efficiency flow path. x This indicates that a slip is present. Therefore, the controller 100 x In response to the slip, the dosage rate is configured to increase by a predetermined amount.

[0177] NO x Slippage can be the result of an underestimated mass flow rate, where the average conversion efficiency is less than a threshold (e.g., a first threshold), or the conversion efficiency of the flow path (e.g., the first and second NO xIn response to determining that the difference in the conversion efficiency is greater than a threshold, the controller 100 is configured to calculate an adjustment factor to balance at least one of the estimated first mass flow rate in the first flow path 22A or the estimated second mass flow rate in the second flow path 22B. The adjustment factor may be configured to reduce the estimated mass flow rate in the event of ammonia slip and reduce the estimated mass flow rate in the event of NO x It may be predetermined by an administrator to increase the estimated mass flow rate in the event of a slip. In this case, the controller 100 will x To increase the reductant dosing rate based on slip, an adjustment factor is applied to the estimated mass flow rate of the low conversion efficiency flow path, and in response to this adjustment, controller 100 is configured to increase the reductant dosing rate based on the increased (e.g., adjusted) mass flow rate.

[0178] In step 1818, the controller 100 (e.g., NO x The circuit 107 is configured to determine whether the low conversion efficiency flow path is improving following applying the adjustment factor or adjusting the reductant dosing rate. To determine whether the low conversion efficiency flow path is improving, the controller 100 determines whether the low NO flow path is improving after adjusting the reductant dosing rate. x Conversion efficiency of the third NO flow path x The conversion efficiency is calculated by the controller 100. x Conversion efficiency, step 1808 or 1812 The third conversion efficiency is compared to a threshold (e.g., a third threshold), which may be similar to the threshold described in step 18. If the third conversion efficiency is less than the threshold, the low conversion efficiency flow path has not improved, and process 1800 proceeds to step 1822. If the third conversion efficiency is greater than or equal to the threshold, the low conversion efficiency flow path has improved, and process 1800 proceeds to step 1820.

[0179] In various configurations, to determine whether the low conversion efficiency flow path is improving, the controller 100 compares the ANR (e.g., new ANR) of the low conversion efficiency flow path after adjusting the dosing rate to a threshold value (e.g., a third threshold value). The threshold value can be based on the ANR of the low conversion efficiency flow path before the adjustment, such as a predefined percentage or amount of improvement from the previous ANR. The threshold value can be a conversion efficiency threshold. In some cases, the controller 100 compares the new ANR to the previous ANR CE to determine whether to maintain the correction factor. The controller 100 can apply one or more subsequent correction factors until the previous value increases to the desired threshold value.

[0180] In step 1820, controller 100 is configured to reset a value for the number of iterations for which the dose rate readjustment has been performed (e.g., incremented in step 1822). After resetting this value, process 1800 proceeds to step 1832.

[0181] In step 1822, the controller 100 determines that the low conversion efficiency flow path has not improved due to an incorrect adjustment (e.g., the direction or amount of the adjustment). The controller 100 increments a value representing the number of iterations the dosage rate has been adjusted (e.g., in this case, the incremented value = 1).

[0182] In step 1824, the controller 100 determines whether the dosing rate of the reductant has been adjusted once. If the dosing rate has been adjusted once (e.g., value = 1), the process 1800 proceeds to step 1826. Otherwise, if the dosing rate has been adjusted more than once (e.g., value > 1), the process 1800 proceeds to, for example, step 1828.

[0183] In step 1826, the controller 100 readjusts the reductant dosing rate in response to determining that the low conversion efficiency flow path did not improve after the initial adjustment. The controller 100 is configured to adjust the dosing rate by a predetermined amount. Because the dosing rate may be over-adjusted, the controller 100 reduces the initial adjustment amount to reduce the dosing rate. rate For example, if the dosing rate is increased (e.g., in step 1816), the controller 100 is configured to decrease the adjusted dosing rate in proportion to the increase (e.g., half, one-third, one-quarter, etc.). In some cases, the controller 100 reapplies or replaces the initial adjustment factor with a different adjustment factor to adjust the estimated mass flow rate. The second adjustment factor may be smaller than the initial adjustment factor so that the correction step is reduced (e.g., the dosing rate is increased by a smaller amount).

[0184] In another example, if the dosing rate is decreased (e.g., in step 1814), the controller 100 is configured to increase the adjusted dosing rate proportional to the amount of the decrease (e.g., half, one-third, one-quarter, etc.). In some cases, the controller 100 reapplies or replaces the initial adjustment factor with a different adjustment factor to adjust the estimated mass flow rate. The second adjustment factor may be smaller than the initial adjustment factor so that the correction step is reduced (e.g., the dosing rate is decreased by a smaller amount).

[0185] Referring back to step 1818, the controller 100 determines whether the low conversion efficiency flow path has improved after readjusting the reductant dosing rate (e.g., decreasing the correction step). To make this determination, the controller 100 adjusts the fourth NO x Calculate the conversion efficiency of the fourth NO x The conversion efficiency is compared to another threshold (e.g., a fourth threshold), which may be similar to or different from the third threshold. In some cases, the controller 100 determines the ANR of the low conversion efficiency flow path after reconditioning. If the low conversion efficiency flow path has improved (e.g., NO xIf so, the process 1800 proceeds to step 1820. If the low conversion efficiency flow path has not yet been improved, the process 1800 proceeds to step 1822 where the value is incremented. At this step, it is greater than 1, so the process proceeds to step 1828.

[0186] At step 1828, the controller 100 resets the values ​​for the corrective adjustments (eg, dose rate adjustments) and the number of adjustments made to the dose rate.

[0187] In step 1830, the controller 100 triggers the fault and proceeds to step 1832. The controller 100 x A fault is triggered in response to determining that the conversion efficiency is less than a fourth threshold. Triggering the fault may include the controller 100 sending a signal or message to the operator I / O device 120 indicating that there is a restriction or imbalance in the aftertreatment system 22 and that a service center should be visited. In some cases, the signal or message may be sent to a device at the service center, for example, for diagnosis or to schedule a service appointment. In some cases, the triggered fault may be a service light on the dashboard of the vehicle including the system 10.

[0188] In step 1832, controller 100 is configured to pause or stop operation in process 1800 and resume operation by proceeding to step 1804. In some cases, if the imbalance is diagnosed or resolved (e.g., the estimated mass flow rate is corrected) after another iteration of process 1800, controller 100 may reset the triggered fault. In various embodiments, by adjusting or correcting the estimated mass flow rate, controller 100 is configured to further adjust at least one of the hydrocarbon dosing or soot loading estimations based on the adjusted mass flow rate of at least one of the flow paths.

[0189] In various embodiments, in response to addressing the ANR and / or conversion efficiency of the low conversion efficiency flow path, the low conversion efficiency flow path becomes a high (or normal) conversion efficiency flow path, and other flow paths may be low conversion efficiency flow paths. Process 1800 may be repeated for the other flow paths (e.g., correcting the estimated mass flow rates of the other flow paths).

[0190] Referring to FIG. 19, the NO associated with FIG. x Graphs of an exemplary process 1900 for monitoring-based correction are shown. Graph 1902 shows an increase in engine exhaust mass flow rate over various time intervals. Graph 1904 shows an increase in catalyst member (e.g., SCR catalyst member 50) bed temperature corresponding to the increased engine exhaust mass flow rate over various time intervals. The sudden increase in temperature can cause ammonia slip in the tailpipe of the respective flow path. The sudden increase in engine exhaust mass flow rate and catalyst temperature can be due to mass flow rate estimation errors due to tailpipe restrictions.

[0191] As shown in graph 1906, the conversion efficiency (e.g., of the SCR catalyst member 50) between the two flow paths and the ANR can be used as a condition indicating an unbalanced system. For example, between the time frame of 4.26 hours and 4.29 hours, the conversion efficiency (e.g., average conversion efficiency) of the two flow paths is below a predetermined threshold (e.g., below 95%, 90%, etc.), or the difference between the conversion efficiencies is equal to or greater than a threshold (e.g., above 3%, 5%, etc.). Furthermore, during the same time frame, the ANR is similar between the first flow path 22A and the second flow path 22B (e.g., approximately 1 to 1.25). Meeting this condition indicates that the mass flow estimation is erroneous due to restrictions in the tailpipe.

[0192] Graph 1908 is NO x Graph 1906 shows the measured values ​​(e.g., parts per million (ppm)), and graph 1910 shows the reductant dosage (e.g., estimated by controller 100 or measured by an ammonia sensor) during the same time frame as graph 1906. As shown, NO xAt a given level, the second flow path 22B allows NO to traverse the system. x providing an excess amount of reducing agent compared to the level.

[0193] Graph 1912 shows the estimated mass flow rates over the same time window as graphs 1906-1910. As shown, the estimated mass flow rates for both first and second flow paths 22B increased from 9 kg / min to 20-22 kg / min between approximately 4.24 and 4.25 hours. In this case, the estimated mass flow rates are inaccurate for at least one flow path due to a tailpipe restriction. Therefore, controller 100 corrects the estimated mass flow rates and adjusts the reductant dosing rate to reduce NO x and configured to perform the operations described in process 1800 to minimize reductant slip, where second flow path 22B is a low flow path but is presumed to be a high flow path, and first flow path 22A is a high flow path but is presumed to be a low flow path relative to second flow path 22B.

[0194] Graph 1914 shows the adjusted estimated mass flow rates after applying adjustment / correction factors to the first flow path 22A and / or the second flow path 22B. For example, there may be reductant slip from the second flow path 22B due to an overestimated mass flow rate, and ammonia slip in the first flow path 22A due to an underestimated mass flow rate. In this case, the correction factors applied to the flow paths include decreasing the estimated mass flow rate for the second flow path 22B and increasing the estimated mass flow rate for the first flow path 22A by a predetermined amount proportional to the overestimation or underestimation of the estimated mass flow rate. The amount of overestimation or underestimation may be proportional to the NO 2 . x It can be based on the level of slip or reductant slip.

[0195] Graph 1916 shows the reductant dosing rate, and graph 1918 shows the measured NO over the same time window as graph 1914 after adjustment. x19 shows the level. As shown, the dosage of the reducing agent is improved after applying the adjustment / correction factor. Based on the improved results from the correction, further correction may be initiated (e.g., increasing the adjustment factor) or the correction may be maintained. Thus, as shown in graph 1920, the conversion efficiency is improved for the first flow path 22A and the second flow path 22B after applying the adjustment factor.

[0196] 3. Construction of an Exemplary Embodiment

[0197] While this specification contains many specific implementation details, these should not be construed as limitations on the scope of what may be claimed, but rather as descriptions of features inherent to particular embodiments. Certain features described herein in the context of separate embodiments may also be implemented in combination in a single implementation. Conversely, various features described in the context of a single implementation may also be implemented in multiple embodiments separately or in any suitable subcombination. Furthermore, while features may be described as working in a particular combination and even initially claimed as such, one or more features from a claimed combination may, in some cases, be deleted from that combination, and the claimed combination may be directed to subcombinations or variations of subcombinations.

[0198] As used herein, the terms "substantially," "generally," "approximately," and similar terms are intended to have broad meanings consistent with common and accepted usage by those of ordinary skill in the art to which the subject matter of this disclosure pertains. These terms should be understood by those of ordinary skill in the art who review this disclosure to enable description of the particular features described and claimed without limiting the scope of those features to the precise numerical ranges provided. These terms should therefore be interpreted as indicating that insubstantial or insignificant modifications or variations of the subject matter described and claimed are considered to be within the scope of the invention as set forth in the appended claims.

[0199] As used herein, terms such as "coupled" refer to the joining of two components directly or indirectly to one another. Such joining may be stationary (e.g., permanent) or movable (e.g., removable or releasable). Such joining may be achieved where the two components, or the two components and any additional intermediate components, are integrally formed with one another as a single, unitary body, or where the two components, or the two components and any additional intermediate components, are attached to one another.

[0200] As used herein, terms like "fluidly coupled" mean that two components or objects have a pathway formed between them through which a fluid, such as air, exhaust gas, liquid reductant, gaseous reductant, aqueous reductant, gaseous ammonia, etc., can flow with or without an intervening component or object. Examples of fluid couplings or configurations for enabling fluid communication may include piping, channels, or any other suitable components for enabling the flow of a fluid from one component or object to another.

[0201] It is important to note that the configurations and arrangements of the systems shown in the various exemplary embodiments are merely illustrative and not limiting in features. All changes and modifications that fall within the spirit and / or scope of the described embodiments are desired to be protected. It is understood that some features may not be necessary, and embodiments lacking various features may be contemplated as being within the scope of this application, the scope being defined by the following claims. When the term "a portion" is used, the item can include a portion and / or the entire item, unless specifically stated to the contrary.

[0202] Also, the term "or" is used in its inclusive sense (rather than its exclusive sense), so that, for example, when used to connect a list of elements, the term "or" means one, some, or all of the elements in the list. Conjunctive language, such as the phrase "at least one of X, Y, and Z," is otherwise understood with the context in which it is generally used to convey that an item, term, etc. can be either X, Y, Z, X and Y, X and Z, Y and Z, or X, Y, and Z (i.e., any combination of X, Y, and Z), unless expressly stated otherwise. Thus, such conjunctive language generally is not intended to imply that a particular embodiment requires that at least one of X, at least one of Y, and at least one of Z, respectively, be present.

[0203] Additionally, the use of ranges of values ​​herein (e.g., W to P, etc.) includes the maximum and minimum values ​​thereof unless otherwise indicated (e.g., W to P includes W and includes P, etc.). Additionally, ranges of values ​​(e.g., W to P, etc.) do not necessarily require the inclusion of intermediate values ​​within the range of values ​​(e.g., W to P can include only W and P, etc.), unless otherwise specified.

Claims

1. 1. An aftertreatment system comprising: a first flow path including one or more first post-treatment components; a second flow path including one or more second post-treatment components; a controller, estimating a first mass flow rate of exhaust gas in the first flow path; estimating a second mass flow rate of the exhaust gas in the second flow path; calculating an estimated total mass flow rate based on the estimated first mass flow rate and the estimated second mass flow rate; calculating a correction factor to balance the estimated first mass flow rate and the estimated second mass flow rate in response to determining that the estimated total mass flow rate is greater than the engine exhaust mass flow rate; using the correction factor to estimate a corrected first mass flow rate of the exhaust gas in the first flow path and a corrected second mass flow rate of the exhaust gas in the second flow path; and a controller configured to adjust at least one of a reductant dosing, a hydrocarbon dosing, or a soot loading estimation based on the corrected first mass flow rate and the corrected second mass flow rate.

2. The controller further comprises:

2. The aftertreatment system of claim 1, configured to regenerate at least one of a first selective catalytic reduction (SCR) catalyst of the one or more first aftertreatment components or a second SCR catalyst of the one or more second aftertreatment components in response to determining that the estimated total mass flow is greater than the engine exhaust mass flow and prior to calculating the correction factor.

3. After regenerating at least one of the first SCR catalyst or the second SCR catalyst and before calculating the correction factor, the controller further estimating a third mass flow rate of the exhaust gas in the first flow path; estimating a fourth mass flow rate of the exhaust gas in the second flow path; and The aftertreatment system of claim 2 , configured to calculate a second estimated total mass flow rate based on the third mass flow rate and the fourth mass flow rate.

4. In response to determining that the estimated total mass flow is greater than the engine exhaust mass flow, the controller further: determining whether the first flow path or the second flow path is newly installed; and The aftertreatment system of claim 1 , configured to calculate the correction factor in response to determining that the first flow path or the second flow path is newly installed.

5. To calculate the correction factor, the controller determining a ratio between a first pressure differential value across a first particulate filter of the one or more first after-treatment components and a second pressure differential value across a second particulate filter of the one or more second after-treatment components; and The aftertreatment system of claim 1 , configured to calculate the correction factor based on the ratio between the first pressure differential value and the second pressure differential value.

6. In response to determining that the estimated total mass flow is greater than the engine exhaust mass flow, the controller further: determining whether the first flow path or the second flow path is newly installed; estimating a soot loading flow rate in response to determining that neither the first flow path nor the second flow path has been newly installed; and The aftertreatment system of claim 1 , configured to calculate the correction factor based on the estimated soot loading flow rate.

7. The controller further comprises: estimating a first virtual mass flow rate of the exhaust gas in the first flow path based on a first pressure differential value across a first particulate filter of the one or more first aftertreatment components; estimating a second virtual mass flow rate of the exhaust gas in the second flow path based on a second pressure differential value across a second particulate filter of the one or more second aftertreatment components; and 2. The aftertreatment system of claim 1, configured to calculate the correction factor based on the engine exhaust mass flow rate and at least one of the estimated first virtual mass flow rate or the estimated second virtual mass flow rate.

8. The controller further comprises: determining a first differential pressure value across a first particulate filter of the one or more first after-treatment components and a second differential pressure value across a second particulate filter of the one or more second after-treatment components over a time window comprising a plurality of time intervals; comparing the first pressure differential value and the second pressure differential value to a set of calibrated tables containing a plurality of predetermined pressure differential values ​​for different flow fractions of the engine exhaust mass flow rate during each of the plurality of time intervals; and 2. The aftertreatment system of claim 1, configured to calculate the correction factor based on the comparison of the first pressure differential value and the second pressure differential value to the set of calibrated tables at the end of the time window.

9. To calculate the correction factor, the controller further comprises: incrementing a score for one of the set of calibrated tables in response to the first pressure differential value and the second pressure differential value matching one of the set of calibrated tables during each of the plurality of time intervals of the time window; and The aftertreatment system of claim 8 , configured to select, at the end of the time window, the flow split corresponding to the set of calibrated tables with the highest score for calculating the correction factor.

10. a controller estimating a first mass flow rate of exhaust gas in a first flow path including one or more first aftertreatment components; the controller estimating a second mass flow rate of the exhaust gas in a second flow path including one or more second aftertreatment components; the controller calculating an estimated total mass flow rate based on the estimated first mass flow rate and the estimated second mass flow rate; In response to determining that the estimated total mass flow rate is greater than an engine exhaust mass flow rate, the controller calculating a correction factor to balance the estimated first mass flow rate and the estimated second mass flow rate; the controller using the correction factor to estimate a corrected first mass flow rate of the exhaust gas in the first flow path and a corrected second mass flow rate of the exhaust gas in the second flow path; the controller adjusting at least one of reductant dosing, hydrocarbon dosing, or soot loading estimation based on the corrected first mass flow rate and the corrected second mass flow rate.

11. 11. The method of claim 10, further comprising the step of: the controller regenerating at least one of a first selective catalytic reduction (SCR) catalyst of the one or more first aftertreatment components or a second SCR catalyst of the one or more second aftertreatment components in response to determining that the estimated total mass flow is greater than the engine exhaust mass flow and prior to the step of calculating the correction factor.

12. after the step of regenerating at least one of the first SCR catalyst or the second SCR catalyst and before the step of calculating the correction factor; the controller estimating a third mass flow rate of the exhaust gas in the first flow path; the controller estimating a fourth mass flow rate of the exhaust gas in the second flow path; The method of claim 11 , further comprising the controller calculating a second estimated total mass flow rate based on the third mass flow rate and the fourth mass flow rate.

13. in response to determining that the estimated total mass flow is greater than the engine exhaust mass flow; the controller determining whether the first flow path or the second flow path is newly installed; The method of claim 10 , further comprising: in response to determining that the first flow path or the second flow path is newly installed, the controller calculating the correction factor.

14. The step of calculating the correction coefficient comprises: the controller determining a ratio between a first pressure differential value across a first particulate filter of the one or more first after-treatment components and a second pressure differential value across a second particulate filter of the one or more second after-treatment components; and the controller calculating the correction factor based on the ratio between the first pressure differential value and the second pressure differential value.

15. in response to determining that the estimated total mass flow is greater than the engine exhaust mass flow; the controller determining whether the first flow path or the second flow path is newly installed; In response to determining that neither the first flow path nor the second flow path is newly installed, the controller estimates a soot load flow rate; The method of claim 10, further comprising the step of: the controller calculating the correction factor based on the estimated soot loading flow rate.

16. the controller estimating a first virtual mass flow rate of the exhaust gas in the first flow path based on a first pressure differential value across a first particulate filter of the one or more first aftertreatment components; the controller estimating a second virtual mass flow rate of the exhaust gas in the second flow path based on a second pressure differential value across a second particulate filter of the one or more second aftertreatment components; 11. The method of claim 10, further comprising the step of the controller calculating the correction factor based on the engine exhaust mass flow rate and at least one of the estimated first virtual mass flow rate or the estimated second virtual mass flow rate.

17. the controller determining a first pressure differential value across a first particulate filter of the one or more first aftertreatment components and a second pressure differential value across a second particulate filter of the one or more second aftertreatment components over a time window comprising a plurality of time intervals; the controller comparing the first pressure differential value and the second pressure differential value during each of the plurality of time intervals to a set of calibrated tables containing a plurality of predetermined pressure differential values ​​for different flow fractions of the engine exhaust mass flow; 11. The method of claim 10, further comprising the step of the controller calculating the correction factor based on the comparison of the first pressure differential value and the second pressure differential value to the set of calibrated tables at the end of the time window.

18. The step of calculating the correction coefficient comprises: during each of the plurality of time intervals of the time window, the controller incrementing a score for the one of the set of calibrated tables in response to the first pressure differential value and the second pressure differential value matching the one of the set of calibrated tables; 18. The method of claim 17, further comprising the step of: the controller selecting, at the end of the time window, the flow split corresponding to the calibrated table set with the highest score for calculating the correction factor.

19. 1. An aftertreatment system comprising: a first flow path including one or more first post-treatment components; a second flow path including one or more second post-treatment components; a controller, the first NO in the first flow path x Calculate the conversion efficiency, a second NO in the second flow path x Calculate the conversion efficiency, The first No. x Conversion efficiency and the second NO x Average NO based on conversion efficiency x Calculate the conversion efficiency, The first No. x Conversion efficiency and the second NO x Calculate the difference in conversion efficiency, Average No. x The conversion efficiency is less than a first threshold value, or the first NO x Conversion efficiency and the second NO x calculating an adjustment factor to balance the estimated first mass flow rate and the estimated second mass flow rate in response to determining that the difference between the conversion efficiency and the estimated first mass flow rate is greater than the first threshold; using the adjustment factor to estimate an adjusted first mass flow rate of the exhaust gas in the first flow path and an adjusted second mass flow rate of the exhaust gas in the second flow path; and a controller configured to adjust at least one of a reductant dosing, a hydrocarbon dosing, or a soot loading estimation based on the adjusted first mass flow rate and the adjusted second mass flow rate.

20. Average No. x If the conversion efficiency is less than the first threshold value or the first NO x Conversion efficiency and the second NO x In response to determining that the difference between the conversion efficiency and the power consumption is greater than the first threshold, the controller further The calculated first NO x Conversion efficiency and the calculated second NO x and extracting a low NOx from one of the first flow path or the second flow path based on the conversion efficiency. x Identify the conversion efficiency flow path and 5. Low NO x Conversion efficiency of ammonia (NH 3 ) vs. NO x Determine the ANR, 5. Low NO x comparing the ANR of the conversion efficiency channel to a second threshold; 5. Low NO x a NO in response to determining that the ANR of the conversion efficiency flow path is less than the second threshold value; x Identifying slippage or low NO x In response to determining that the ANR of the conversion efficiency channel is greater than or equal to the second threshold, 3 Identify the slip, and No. x Slip or NH 3 20. The aftertreatment system of claim 19, configured to calculate the adjustment factor for adjusting a dosing rate of reductant in the aftertreatment system based on slip.

21. To adjust the dosage rate of the reducing agent, the controller further x increasing the dosing rate of the reductant in the aftertreatment system by a first amount in response to slip, or 3 21. The aftertreatment system of claim 20, configured to decrease the dosing rate of the reductant in the aftertreatment system by a second amount in response to slip.

22. The controller further comprises: After adjusting the dosage rate of the reducing agent, x Conversion efficiency of the third NO flow path x Calculate the conversion efficiency, and The third no. x 21. The aftertreatment system of claim 20, configured to readjust the dosing rate of the reductant in response to determining that the conversion efficiency is less than a third threshold.

23. The controller further comprises: After readjusting the dosage rate of the reducing agent, x Conversion efficiency of the fourth NO flow path x Calculate the conversion efficiency, and The fourth NO x 23. The aftertreatment system of claim 22, configured to trigger a fault in response to determining that the conversion efficiency is less than a fourth threshold.

24. a controller controlling a first NO in a first flow path including one or more first after-treatment components; x calculating the conversion efficiency; the controller controls a second NO in a second flow path that includes one or more second post-treatment components. x calculating the conversion efficiency; The controller x Conversion efficiency and the second NO x Average NO based on conversion efficiency x calculating the conversion efficiency; The controller x Conversion efficiency and the second NO x calculating the difference between the conversion efficiencies; Average No. x The conversion efficiency is less than a first threshold value, or the first NO x Conversion efficiency and the second NO x in response to determining that the difference between the estimated first mass flow rate and the estimated second mass flow rate is greater than the first threshold, the controller calculating an adjustment factor to balance the estimated first mass flow rate and the estimated second mass flow rate; the controller using the adjustment factor to estimate an adjusted first mass flow rate of the exhaust gas in the first flow path and an adjusted second mass flow rate of the exhaust gas in the second flow path; the controller adjusting at least one of reductant dosing, hydrocarbon dosing, or soot loading estimation based on the adjusted first mass flow rate and the adjusted second mass flow rate.

25. Average No. x If the conversion efficiency is less than the first threshold value or the first NO x Conversion efficiency and the second NO x in response to determining that the difference between the conversion efficiency is greater than the first threshold value. The controller calculates the first NO x Conversion efficiency and the calculated second NO x and extracting a low NOx from one of the first flow path or the second flow path based on the conversion efficiency. x identifying a conversion efficiency flow path; The controller x Conversion efficiency of ammonia (NH 3 ) vs. NO x determining an ANR; The controller x comparing the ANR of the conversion efficiency channel to a second threshold; The controller x a NO in response to determining that the ANR of the conversion efficiency flow path is less than the second threshold value; x Identifying slippage or low NO x In response to determining that the ANR of the conversion efficiency channel is greater than or equal to the second threshold, 3 identifying a slip; The controller x Slip or NH 3 25. The method of claim 24, further comprising: calculating the adjustment factor for adjusting a dosing rate of a reductant in an aftertreatment system based on slip.

26. The step of adjusting the dosage rate of the reducing agent comprises: The controller x increasing the dosing rate of the reductant in the aftertreatment system by a first amount in response to slip, or 3 26. The method of claim 25, including decreasing the dosing rate of the reductant in the aftertreatment system by a second amount in response to slip.

27. After the controller adjusts the dosing rate of the reductant, x Conversion efficiency of the third NO flow path x calculating the conversion efficiency; The controller x 26. The method of claim 25, further comprising: readjusting the dosage rate of the reducing agent in response to determining that the conversion efficiency is less than a third threshold.

28. After the controller readjusts the dosing rate of the reductant, x Conversion efficiency of the fourth NO flow path x calculating the conversion efficiency; The controller x 28. The method of claim 27, further comprising: triggering a fault in response to determining that the conversion efficiency is less than a fourth threshold.

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