Systems and methods for managing mass flow distribution in a multi-train post-treatment system

Abstract

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

Description

TECHNICAL FIELD

[0001] The present application relates generally to aftertreatment systems and, more particularly, to managing mass flow distribution in the aftertreatment system. BACKGROUND

[0002] Combustion engines, such as diesel engines, emit exhaust gases containing nitrogen oxide (NO x ) compounds. It may be desirable to use NO x emissions, for example to comply with environmental regulations. To reduce NO x To reduce NOx emissions, a reducing agent can be dosed into the exhaust gas through a dosing system in an aftertreatment system. The reducing agent interacts with a catalyst of a catalyst element to convert a portion of the exhaust gas into non-NO x emissions, such as nitrogen (N2), carbon dioxide (CO2) and water (H2O), thereby reducing NO x-Emissions can be reduced. In some applications, these exhaust gas compounds can be filtered or removed by one or more catalyst elements (e.g., a diesel oxidation catalyst (DOC) element, a selective catalytic reduction (SCR) catalyst element, a diesel particulate filter (DPF) element, an ammonia oxidation (AMOx) catalyst element, etc.) located in an aftertreatment system. SUMMARY

[0003] Certain aftertreatment systems may include multiple trains for reducing exhaust byproducts from exhaust gas produced by an internal combustion engine. Each train within the aftertreatment system includes one or more components for reducing the exhaust byproducts, such as catalyst elements (e.g., SCR catalyst elements, DOC elements, etc.) or filters (such as DPF elements). A mass flow rate of the exhaust byproducts passing through each train can be used to determine the dosage of ammonia (NH3) (e.g., reductant) to reduce the exhaust byproducts.

[0004] However, due to certain pipe restrictions or blockages within the aftertreatment system, the exhaust mass flow distribution may be uneven across the branches (e.g., the flow rate of exhaust gas in one branch may be different from another). Mass flow distribution refers to a ratio of mass flow (or mass flow) distributed across the branches of the aftertreatment system. The restriction can be caused by a number of factors, including, but not limited to, an asymmetric tailpipe or other improper aftertreatment system installation, soot loading, deposition, etc. The restriction within the aftertreatment system causes an inaccuracy in the mass flow estimation, which can affect, at a minimum, reductant dosing, hydrocarbon (HC) dosing, and / or soot loading estimation, etc.Consequently, the inaccurate mass flow estimation may lead to at least one of NH3 slip, early or delayed regeneration triggers, and / or poor regeneration control. Therefore, the systems, methods, and devices described herein are configured to identify any constraint within the aftertreatment system and provide a correction to the mass flow estimation, thereby adjusting at least one of reductant dosing, HC dosing, and / or soot loading estimation according to the flow split to minimize, for example, reductant slip, a late trigger of a regeneration event, or poor regeneration control.

[0005] In some embodiments, an aftertreatment system includes a first branch including one or more first aftertreatment components, a second branch including one or more second aftertreatment components, and a controller. The controller is configured to estimate a first mass flow of exhaust gas in the first branch. The controller is configured to estimate a second mass flow of exhaust gas in the second branch. The controller is configured to calculate an estimated total mass flow based on the estimated first mass flow and the estimated second mass flow. In response to determining that the estimated total mass flow is greater than an engine exhaust mass flow, the controller is configured to calculate a correction factor to balance the estimated first mass flow and the estimated second mass flow.The controller is configured to estimate a corrected first mass flow of the exhaust gas in the first branch and a corrected second mass flow of the exhaust gas in the second branch using the correction factor. The controller is configured to adjust at least one of a reductant dosage, hydrocarbon dosage, or soot loading estimate based on the corrected first mass flow and the corrected second mass flow.

[0006] 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 is greater than the engine exhaust mass flow and prior to calculating the correction factor. In some embodiments, following regenerating the at least one of the first SCR catalyst or the second SCR catalyst and prior to calculating the correction factor, the controller is further configured to: estimate a third mass flow of exhaust gas in the first train; estimate a fourth mass flow of exhaust gas in the second train; and calculate a second estimated total mass flow based on the third mass flow and the fourth mass flow.

[0007] In some embodiments, in response to determining that the estimated total mass flow is greater than the engine exhaust mass flow, the controller is further configured to: determine whether the first branch or the second branch is newly installed; and calculate the correction factor in response to determining that the first branch or the second branch 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 calculate the correction factor based on the ratio between the first pressure differential value and the second pressure differential value.

[0008] In some embodiments, in response to determining that the estimated total mass flow is greater than the engine exhaust mass flow, the controller is further configured to: determine whether the first leg or the second leg is newly installed; estimate a soot loading flow in response to determining that neither the first leg nor the second leg is newly installed; and calculate the correction factor based on the estimated soot loading flow.

[0009] In some embodiments, the controller is further configured to estimate a first virtual mass flow of exhaust gas in the first train based on a first pressure difference value across a first particulate filter of the one or more first aftertreatment components. The controller is configured to estimate a second virtual mass flow of exhaust gas in the second train based on a second pressure difference value across a second particulate filter of the one or more second aftertreatment components. The controller is configured to calculate the correction factor based on the engine exhaust mass flow and at least one of the estimated first virtual mass flow or the estimated second virtual mass flow.

[0010] In some embodiments, the controller is further configured to determine a first pressure difference value across a first particulate filter of the one or more first aftertreatment components and a second pressure difference 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 is configured to compare, at each of the plurality of time intervals, the first pressure difference value and the second pressure difference value to a set of calibrated tables comprising a plurality of predetermined pressure difference values ​​for different flow splits of the engine exhaust mass flow. The controller is configured to calculate the correction factor based on the comparison between the first pressure difference value and the second pressure difference value to the set of calibrated tables at one end of the time window.

[0011] In some embodiments, to calculate the correction factor, the controller is further configured to: in each of the plurality of time intervals of the time window, increment a score for one of the set of calibrated tables in response to the first pressure difference value and the second pressure difference value matching the one of the set of calibrated tables; and selecting, at the end of the time window, a stream split corresponding to the set of calibrated tables with a highest score to calculate the correction factor.

[0012] In some embodiments, a method comprises: estimating, by a controller, a first mass flow of exhaust gas in a first branch including one or more first aftertreatment components; estimating, by the controller, a second mass flow of the exhaust gas in a second branch including one or more second aftertreatment components; calculating, by the controller, an estimated total mass flow based on the estimated first mass flow and the estimated second mass flow; in response to determining that the estimated total mass flow is greater than an engine exhaust mass flow, calculating, by the controller, a correction factor to compensate for the estimated first mass flow and the estimated second mass flow;Estimating, by the controller, a corrected first mass flow of the exhaust gas in the first branch and a corrected second mass flow of the exhaust gas in the second branch using the correction factor; and adjusting, by the controller, at least one of a reductant dosage, hydrocarbon dosage, or soot loading estimate based on the corrected first mass flow and the corrected second mass flow.

[0013] In some embodiments, the method further comprises 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 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.

[0014] In some embodiments, following regenerating the at least one of the first SCR catalyst or the second SCR catalyst and prior to calculating the correction factor, the method further comprises: estimating, by the controller, a third mass flow of the exhaust gas in the first branch; estimating, by the controller, a fourth mass flow of the exhaust gas in the second branch; and calculating, by the controller, a second estimated total mass flow based on the third mass flow and the fourth mass flow.

[0015] In some embodiments, the method comprises, in response to determining that the estimated total mass flow is greater than the engine exhaust mass flow: determining, by the controller, whether the first branch or the second branch is newly installed; and calculating, by the controller, the correction factor in response to determining that the first branch or the second branch is newly installed.

[0016] In some embodiments, calculating the correction factor comprises: determining, by the controller, a ratio between a first pressure difference value across a first particulate filter of the one or more first aftertreatment components and a second pressure difference 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 difference value and the second pressure difference value.

[0017] In some embodiments, the method comprises, in response to determining that the estimated total mass flow is greater than the engine exhaust mass flow: determining, by the controller, whether the first leg or the second leg is newly installed; estimating, by the controller, a soot loading flow in response to determining that neither the first leg nor the second leg is newly installed; and calculating, by the controller, the correction factor based on the estimated soot loading flow.

[0018] In some embodiments, the method further comprises: estimating, by the controller, a first virtual mass flow of the exhaust gas in the first train based on a first pressure differential value across a first particulate filter of the one or more first aftertreatment components; estimating, by the controller, a second virtual mass flow of the exhaust gas in the second train based on 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 engine exhaust mass flow and at least one of the estimated first virtual mass flow or the estimated second virtual mass flow.

[0019] In some embodiments, the method further comprises determining, by the controller, a first pressure difference value across a first particulate filter of the one or more first aftertreatment components and a second pressure difference 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, in each of the plurality of time intervals, the first pressure difference value and the second pressure difference value to a set of calibrated tables comprising a plurality of predetermined pressure difference values ​​for different flow splits of the engine exhaust mass flow; and calculating, by the controller, the correction factor based on the comparison between the first pressure difference value and the second pressure difference value to the set of calibrated tables at one end of the time window.

[0020] In some embodiments, calculating the correction factor comprises: in each of the plurality of time intervals of the time window, incrementing, by the controller, a score for one of the set of calibrated tables in response to the first pressure difference value and the second pressure difference value matching the one of the set of calibrated tables; and selecting, by the controller, at the end of the time window, a stream split corresponding to the set of calibrated tables with a highest score to calculate the correction factor.

[0021] In some embodiments, an aftertreatment system includes a first train including one or more first aftertreatment components, a second train including one or more second aftertreatment components, and a controller. The controller is configured to calculate a first NOx conversion efficiency of the first train. The controller is configured to calculate a second NOx conversion efficiency of the second train. The controller is configured to calculate an average NOx conversion efficiency based on the first NOx conversion efficiency and the second NOx conversion efficiency. The controller is configured to calculate a difference between the first NOx conversion efficiency and the second NOx conversion efficiency.In response to determining that the average NOx conversion efficiency is less than a first threshold or the difference between the first NOx conversion efficiency and the second NOx conversion efficiency is greater than the first threshold, the controller is configured to calculate an adjustment factor to balance an estimated first mass flow and an estimated second mass flow. The controller is configured to estimate an adjusted first mass flow of the exhaust gas in the first train and an adjusted second mass flow of the exhaust gas in the second train using the adjustment factor. The controller is configured to adjust at least one of a reductant dosage, a hydrocarbon dosage, or a soot loading estimate based on the adjusted first mass flow and the adjusted second mass flow.

[0022] In some embodiments, in response to determining that the average NOx conversion efficiency is less than the first threshold or the difference between the first NOx conversion efficiency and the second NOx conversion efficiency is greater than the first threshold, the controller is further configured to: identify a low NOx conversion efficiency leg from the first leg or the second leg based on the calculated first NOx conversion efficiency and the calculated second NOx conversion efficiency. The controller is configured to determine an ammonia (NH3) to NOx ratio (ANR) of the low NOx conversion efficiency leg. The controller is configured to compare the ANR of the low NOx conversion efficiency leg to a second threshold.The controller is configured to identify NOx slip in response to determining that the ANR of the low NOx conversion efficiency train is less than the second threshold, or NH3 slip in response to determining that the ANR of the low NOx conversion efficiency train is greater than or equal to the second threshold. The controller is configured to calculate the adjustment factor to adjust a dosing rate of the reductant in the aftertreatment system based on the NOx slip or the NH3 slip.

[0023] In some embodiments, to adjust the dosing rate of the reductant, the controller is further configured to increase the dosing rate of the reductant in the aftertreatment system by a first amount in response to the NOx slip or to decrease the dosing rate of the reductant in the aftertreatment system by a second amount in response to the NH3 slip.

[0024] In some embodiments, the controller is further configured to calculate a third NOx conversion efficiency of the low NOx conversion efficiency train following the adjustment of the reductant dosing rate. The controller is configured to readjust the reductant dosing rate in response to determining that the third NOx conversion efficiency is less than a third threshold.

[0025] In some embodiments, the controller is configured to calculate a fourth NOx conversion efficiency of the low NOx conversion efficiency train following readjustment of the reductant dosing rate. The controller is configured to trigger a fault in response to determining that the fourth NOx conversion efficiency is less than a fourth threshold.

[0026] In some embodiments, a method comprises: calculating, by a controller, a first NOx conversion efficiency of a first train including one or more first aftertreatment components; calculating, by the controller, a second NOx conversion efficiency of a second train including one or more second aftertreatment components; calculating, by the controller, an average NOx conversion efficiency based on the first NOx conversion efficiency and the second NOx conversion efficiency; calculating, by the controller, a difference between the first NOx conversion efficiency and the second NOx conversion efficiency;in response to determining that the average NOx conversion efficiency is less than a first threshold or the difference between the first NOx conversion efficiency and the second NOx conversion efficiency is greater than the first threshold, calculating, by the controller, an adjustment factor to compensate for an estimated first mass flow and an estimated second mass flow; estimating, by the controller, an adjusted first mass flow of the exhaust gas in the first train and an adjusted second mass flow of the exhaust gas in the second train using the adjustment factor; and adjusting, by the controller, at least one of a reductant dosage, a hydrocarbon dosage, or a soot loading estimate based on the adjusted first mass flow and the adjusted second mass flow.

[0027] In some embodiments, in response to determining that the average NOx conversion efficiency is less than the first threshold or the difference between the first NOx conversion efficiency and the second NOx conversion efficiency is greater than the first threshold, the method further comprises: identifying, by the controller, a low NOx conversion efficiency leg from the first leg or the second leg based on the calculated first NOx conversion efficiency and the calculated second NOx conversion efficiency; determining, by the controller, an ammonia (NH3) to NOx ratio (ANR) of the low NOx conversion efficiency leg; comparing, by the controller, the ANR of the low NOx conversion efficiency leg to a second threshold;Identifying, by the controller, a NOx slip in response to determining that the ANR of the low NOx conversion efficiency train is less than the second threshold, or an NH3 slip in response to determining that the ANR of the low NOx conversion efficiency train is greater than or equal to the second threshold; and calculating, by the controller, the adjustment factor to adjust a dosing rate of the reductant in the aftertreatment system based on the NOx slip or the NH3 slip.

[0028] In some embodiments, adjusting the dosing rate of the reductant comprises: increasing, by the controller, the dosing rate of the reductant in the aftertreatment system by a first amount in response to the NOx slip or decreasing, by the controller, the dosing rate of the reductant in the aftertreatment system by a second amount in response to the NH3 slip.

[0029] In some embodiments, the method further comprises: calculating, by the controller, a third NOx conversion efficiency of the low NOx conversion efficiency train following adjusting the reductant dosing rate; and readjusting, by the controller, the reductant dosing rate in response to determining that the third NOx conversion efficiency is less than a third threshold.

[0030] In some embodiments, the method further comprises: calculating, by the controller, a fourth NOx conversion efficiency of the low NOx conversion efficiency train following readjusting the reductant dosing rate; and triggering, by the controller, a fault in response to determining that the fourth NOx conversion efficiency is less than a fourth threshold. BRIEF DESCRIPTION OF THE CHARACTERS

[0031] The details of one or more embodiments are set forth in the accompanying drawings and the following description. Other features, aspects, and advantages of the disclosure will become apparent from the description, drawings, and claims, in which: Fig. 1 is an exemplary schematic diagram of an engine exhaust aftertreatment system coupled to a controller; Fig. 2 is an exemplary schematic diagram of the control system associated with the engine system of Fig. 1 is used; Fig. 3 is an exemplary graph illustrating a correlation between mass flow splitting errors relative to a constraint difference between the strings; Fig. Figure 4 is an exemplary graph illustrating a correlation between ammonia slips relative to the constraint difference between strands; Fig. Figure 5 is an exemplary diagram illustrating characteristics of pressure differences and volumetric flows (e.g., in actual cubic meters per second (ACMS)) relative to particular flow partitions; Fig. Figure 6 is another exemplary diagram illustrating characteristics of pressure differences and volumetric flows relative to particular flow partitions; Fig. 7 is an overview process flow diagram for an exemplary process for managing mass flow splitting in a multi-line aftertreatment system of the engine system of Fig. 1 is; Fig. 8 an exemplary process flow diagram for performing an exemplary proportionality correction of Fig. 7 in greater detail; Fig. 9 diagrams illustrating certain exemplary processes that can be performed using a delta pressure-based correction process of Fig. 8 are associated, in greater detail; Fig. 10 is a block diagram showing an example matching model of Fig. 8 in greater detail; Fig. 11 is an example diagram illustrating a model-based approach of Fig. 8 represents an inlet pipe restriction; Fig. 12 is an example diagram illustrating a model-based approach of Fig. 8 represents a tailpipe restriction; Fig. 13 exemplary diagrams showing monitored data for a model-based approach of Fig. 8, wherein 50-50 current distribution data are compared with a respective current distribution table; Fig. 14 example diagrams showing monitored data for a model-based approach of Fig. 8, wherein 40-60 current distribution data are compared with a respective current distribution table; Fig. 15 example diagrams showing monitored data for a model-based approach of Fig. 8, wherein 60-40 current distribution data are matched with at least one respective current distribution table; Fig. 16 example diagrams showing monitored data for a model-based approach of Fig. 8, wherein 50-50 current distribution data of a non-road transient cycle (NRTC) of a test cell (TC) are compared with at least one respective current distribution table; Fig. 17 is an overview process flow diagram of another exemplary process for managing mass flow splitting in a multi-lane aftertreatment system of the engine system of Fig. 1 is; Fig. 18 is a process flow diagram of the exemplary process for managing mass flow splitting in a multi-train aftertreatment system, which Fig. 17, as described in more detail; and Fig. 19 diagrams of an exemplary NOx monitoring-based correction process, which Fig. 18 belongs.

[0032] It is understood that some or all of the figures are schematic representations for illustrative purposes. The figures are provided for the purpose of illustrating one or more embodiments with the express understanding that they are not to be used to limit the scope or meaning of the claims. DETAILED DESCRIPTION

[0033] The following are more detailed descriptions of various concepts relating to and embodiments of methods, apparatus, and for determining an efficiency value associated with a catalyst element. The various concepts introduced above and discussed in more detail below may be implemented in any of a number of ways, as the described concepts are not limited to any particular implementation. Examples of specific embodiments and applications are provided primarily for illustrative purposes. I. Overview

[0034] Internal combustion engines (e.g., diesel engines, etc.) produce exhaust gas (e.g., sometimes referred to as exhaust). Depending on the fuel consumed by an internal combustion engine, the exhaust gas can contain different by-products (e.g., NO x, carbon monoxide (CO), unburned hydrocarbons (HC), etc.). The byproduct of the exhaust gas may be measured or sampled by one or more sensors of an aftertreatment system, for example, by measuring the density, volume, parts per million (ppm), etc. of the exhaust gas. The aftertreatment system may be coupled to the engine, for example, connected via an exhaust pipe from the engine. For simplicity, the examples herein may refer to NO x than the by-products of the exhaust gas and the sensor can detect NO x -Sensor structured to detect NO x emissions downstream of the engine (e.g., at any position along the exhaust pipe). Although the examples described show a NO x -Sensor that detects NO x -by-product, the systems described can be applied to other sensors.

[0035] The exhaust byproducts may be reduced by one or more aftertreatment components of an engine system that includes an aftertreatment system, such as a DOC element or an SCR catalyst element, among other types of catalysts. The aftertreatment system may include multiple strands. For simplicity, the examples herein provide the aftertreatment system including two strands, however, the aftertreatment system may include more than two strands having respective component(s) for reducing the exhaust byproducts. For example, the exhaust may flow or traverse through the aftertreatment system via a first strand and a second strand. The catalyst element (e.g., SCR catalyst element, DOC element, etc.) of each strand may facilitate chemical reactions of the byproducts and the reductant to reduce or minimize emissions from a tailpipe of the engine system.For simplicity, the examples herein may provide the SCR catalyst element or the DOC element as the catalyst element of the aftertreatment system. Each train of the aftertreatment system may be dosed with ammonia (NH3) (e.g., reductant) to reduce the exhaust byproduct. The reductant dosage may be based on the exhaust mass flow of the exhaust gas passing through the respective train.

[0036] However, due to certain pipe restrictions or blockages within the aftertreatment system, the exhaust gas mass flow distribution may be uneven across the branches (e.g., the flow rate of one branch differs from another). Mass flow distribution refers to the ratio / proportion / percentage of mass flow (or mass flow) divided between the respective branches of the aftertreatment system. The restriction can be caused by a number of factors, including, but not limited to, an asymmetric tailpipe or other improper installation of the aftertreatment system, soot loading, deposition, etc. Furthermore, depending on the location of the restriction, the measured pressure value (e.g.,Catalyst outlet pressure), which in some cases may be used to estimate the mass flow at the respective trains, may not be representative of the actual mass flow of the trains. This leads to inaccuracy in the mass flow estimation, which can affect at least the reductant dosing, hydrocarbon (HC) dosing, and / or soot loading estimation, etc. Consequently, the inaccurate mass flow estimation can, for example, lead to at least one of NH3 slip, early or delayed regeneration triggers, and / or poor regeneration control. Therefore, it is desirable to identify any limitation within the aftertreatment system, calculate a correction / adjustment factor representing the actual mass flow split, and correct the estimated mass flow according to the actual flow split between the trains.It is also desirable to subsequently adjust at least one of reductant dosing, HC dosing, and / or soot loading estimation according to the flow split to minimize, for example, reductant slip, untimely triggering of a regeneration event, or poor regeneration control.

[0037] The systems and methods described herein include at least one controller (e.g., computing device or data processing system) including at least one processor coupled to at least one memory. In some cases, the controller may be embedded in a system that includes the internal combustion engine, the one or more sensors, and the aftertreatment system. In some cases, the controller may be external to the system, such as a server or cloud computing device in communication 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 the sensors that monitor the internal combustion engine or the aftertreatment system.

[0038] In various arrangements, the controller is configured to calculate or estimate mass flow rates of exhaust gas traversing the branches (e.g., a first branch and a second branch) of the aftertreatment system. The controller may estimate the mass flow rate based on pressure data, such as pressure differential (e.g., delta pressure) across a catalyst or catalyst 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 rate to an exhaust gas mass flow rate from the engine to determine any imbalance in flow split (e.g., uneven mass flow rate) between the branches.The imbalance may be caused by some type of restriction within the tailpipe or aftertreatment system, such as deposition, soot loading, asymmetric tailpipe (either by design or due to misalignment of at least one of the strands), etc. The controller is configured to calculate a correction factor to compensate for the estimated mass flows. The correction factor may be based on a variety of variables, including whether one or more aftertreatment system components have been regenerated, whether the aftertreatment system is newly installed, etc. By applying the correction factor to the estimated mass flow of each strand, the controller is configured to estimate the corrected mass flows of the strands and adjust at least one of reductant dosing, hydrocarbon dosing, or soot loading estimation accordingly. Therefore, the systems and methods may NO. x- and reductant slip and control the regeneration trigger for one or more catalysts within an unbalanced aftertreatment system.

[0039] In certain arrangements, the control is configured to increase conversion efficiency (e.g. NO x conversion efficiency) to determine an imbalance between the trains and adjust the estimated mass flows. For example, the controller is configured to detect a NO x -Conversion efficiency of the respective strands, for example using NO x -Sensors (e.g. monitoring the reduction of NO x via the aftertreatment system). Based on the NO x -Conversion efficiency of the strands, the controller is configured to control at least one of an average of the NO x -conversion efficiencies or a difference between the NO x-Conversion efficiencies of the strands. Then, if at least one of the average NO x conversion efficiency 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 by applying the adjustment factor to the estimated flows (e.g., based on pressure data). Based on the adjusted mass flow across the first train and the second train, the controller is configured to adjust at least one of the reductant dosing (e.g., dosing duration, frequency, or timing), hydrocarbon dosing, or soot loading estimation. Therefore, the systems and methods may further determine the amount of NO x and / or reducing agents at the tailpipe and minimize the NO x-Maintain conversion efficiency above a desired efficiency level.

[0040] Through these features, embodiments described herein are capable of alerting a user about the use of contaminated fuel and also alerting a user about the aging of a catalyst element beyond a desired amount. As a result, embodiments described herein are capable of reducing costs associated with warranty maintenance and / or replacements that may be performed when contaminated fuel is consumed by an engine system. II. Overview of the multi-line aftertreatment engine system

[0041] With general reference to the figures, the various embodiments disclosed herein relate to systems, apparatus, and methods for managing mass flow distribution in a multi-train aftertreatment system. Components in aftertreatment systems for reducing byproducts (e.g., NO x , soot, etc.) of the exhaust gas include an SCR system that uses a two-stage process to remove harmful NO x-emissions present in the exhaust gas, or a DOC element to filter or oxidize hydrocarbons, carbon monoxide, or unburned fuel and oil. With regard to SCR, a doser first injects a reductant into the exhaust stream. This reductant can be urea, diesel exhaust fluid (DEF), AdBlue®, urea water solution (UWS), an aqueous urea solution (e.g., AUS32, etc.), or another similar fluid. The reductant can decompose into NH3 after injection. This mixture is then passed through an SCR catalyst element, which, at a specific temperature, causes a reaction in the mixture that removes the harmful NO x -particles into pure nitrogen and water. During operation, undecomposed reducing agent and unreacted ammonia can be stored within the catalyst element (e.g. SCR catalyst element) to be combined with the exhaust product (e.g. NO x-particles, etc.) to be chemically converted.

[0042] The amount of reductant injected into the aftertreatment system (e.g., each leg of a multi-leg aftertreatment system) is based at least in part on an estimated exhaust gas mass flow. The mass flow may be estimated based on pressure data collected / sampled / measured by at least one pressure sensor in the aftertreatment system. However, if there is a restriction in the aftertreatment system, the estimated mass flow may be inaccurate. For example, certain system configurations may respond to a higher estimated mass flow with a higher reductant dosage (e.g., an increase in the rate or duration of reductant dosage) and to a lower estimated mass flow with a lower reductant dosage (e.g., a decrease in the rate or duration of reductant dosage).Due to the inaccuracy in estimating the mass flow, these system configurations may overdose at least one train, resulting in ammonia slip, or underdose at least one train, resulting in NO. x-Slip. Other factors influenced by the inaccurate mass flow estimate include, but are not limited to, premature or delayed catalyst regeneration initiation, poor regeneration control (e.g., hydrocarbon over-dosing or under-dosing), or overloading (e.g., soot and deposit loading) of at least one of the trains, to list a few. Therefore, the systems and methods discussed herein may perform features and operations to estimate the flow split (e.g., mass flows) between the aftertreatment system trains, calculate a correction / adjustment factor to adjust the estimated flow split, and adjust at least one of a reductant dosage, hydrocarbon dosage, or soot loading estimate according to the adjusted flow split.

[0043] With reference to Fig. 1 shows a schematic diagram of a system 10 having a controller 100 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 that is in exhaust-receiving communication with the engine. As shown, the exhaust aftertreatment system 22 is comprised of multiple strands (e.g., first strand 22A and second strand 22B), each strand including one or more components of the exhaust aftertreatment system. Although two strands are shown and described herein for exemplary purposes, the exhaust aftertreatment system 22 may include more than two strands comprised of additional component(s) 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 implemented in a vehicle.The vehicle may include an on-road or off-road vehicle, including, but not limited to, line trucks, medium-range trucks (e.g., pickup trucks), cars, boats, tanks, aircraft, locomotives, mining equipment, and any other type of vehicle. The vehicle may include a transmission, a refueling system, one or more additional vehicle subsystems, etc. In this regard, the vehicle may include additional, fewer, and / or different components / systems, so the principles, methods, systems, devices, processes, and the like of the present disclosure are intended to be applicable with any other vehicle configuration.It should also be understood that the principles of the present disclosure should not be construed as being limited to vehicles; rather, the present disclosure is also applicable to stationary equipment such as a power generator or generator set.

[0044] The engine 20 may be a compression-ignition internal combustion engine that uses diesel fuel. In various other embodiments, the engine 20 may be structured as any other type of engine (e.g., spark-ignition) that uses 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 including one or more electric motors, a fuel cell vehicle, and so on. Thus, while the engine 20 is structured as a diesel-powered internal combustion engine herein, other embodiments are contemplated as falling within the scope of the present disclosure.

[0045] Within the internal combustion engine 20, air from the atmosphere is combined with fuel and combusted to power the engine. The combustion of the fuel and air in the compression chambers of the engine 20 produces exhaust gas, which is operatively delivered to an exhaust manifold (not shown) and to the aftertreatment system 22.

[0046] Each of the strands (e.g., the first strand 22A and the second strand 22B) of the exhaust aftertreatment system 22 includes a diesel oxidation catalyst (DOC) element 30, a diesel particulate filter (DPF) element 40, a selective catalytic reduction (SCR) system 52 with an SCR catalyst element 50, and an ammonia oxidation (AMOx) catalyst element 60. The first strand 22A includes the DOC element 30A, the DPF element 40A, the SCR system 52A with a first SCR catalyst element 50A, and the AMOx catalyst element 60A. The second branch 22B includes the DOC element 30B, the DPF element 40B, the SCR system 52B with a second SCR catalyst element 50B and the AMOx catalyst element 60B.For simplicity, the components of the respective strands described herein may be generally referred to, for example, as DOC element 30, DPF element 40, SCR system 52 with a respective SCR catalyst element 50 and AMOx catalyst element 60 associated with the respective first strand 22A or the second strand 22B.

[0047] The exhaust aftertreatment system 22 further includes an exhaust gas recirculation (EGR) system 70. The SCR systems 52A and 52B of the respective trains further include reductant delivery systems having diesel exhaust fluid (DEF) sources 54A-B (e.g., DEF source 54 of the trains) that supply DEF to DEF dosers 56A-B (e.g., generally referred to as doser 56 for the first train 22A and the second train 22B) via respective DEF lines 58A-B.

[0048] In an exhaust gas flow direction, as 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 in the first branch 22A into the DOC element 30 and exits the DOC element 30 into a first section of the exhaust pipe 28A. From the first section of the exhaust pipe 28A, the exhaust gas flows into the DPF element 40 and exits the DPF element 40 into a second section of the exhaust pipe 28B. From the second section of the exhaust pipe 28B, the exhaust gas flows into the SCR catalyst element 50 and exits the SCR catalyst element 50 into the third section of the exhaust pipe 28C. As the exhaust gas flows through the second section of the exhaust pipe 28B, it is periodically dosed with DEF (or reductant) by the DEF (or reductant) doser 56.Accordingly, the second section of the exhaust pipe 28B acts as a decomposition chamber or tube to facilitate the decomposition of DEF into ammonia. From the third section of the exhaust pipe 28C, the exhaust flows into the AMOx catalyst element 60 and exits the AMOx catalyst element 60 into the exhaust pipe 26 before being expelled from the aftertreatment system 22. Similarly, in the second branch 22B, the exhaust flows through the pipes 28D-28F, passing through the various components in the second branch 22B, and into the exhaust pipe 26.

[0049] Based on the foregoing, in the illustrated embodiment, the DOC element 30 (e.g., the DOC element 30A or the DOC element 30B) is positioned upstream of the DPF element 40 (e.g., the DPF element 40A or the DPF element 40B) and the SCR catalyst element 50 (e.g., the SCR catalyst element 50A or the SCR catalyst element 50B), and the SCR catalyst element 50 (e.g., the SCR catalyst element 50A or the SCR catalyst element 50B) is downstream of the DPF element 40 (e.g., the DPF element 40A or the DPF element 40B) and upstream of the AMOx catalyst element 60 (e.g., the AMOx catalyst element 60A or AMOx catalyst element 60B). However, in alternative embodiments, other arrangements of the components of the exhaust aftertreatment system 22 are also possible. Furthermore, and for the sake of simplicity, the components of one train in the exhaust aftertreatment system 22 may be similar to another train.Alternatively, one or more components or the arrangement of components in the first strand 22A may differ from those in the second strand 22B, and so on.

[0050] The DOC element 30 can be structured to have any number of different types of flow configurations. The DOC element 30 can be structured to oxidize at least some particulate matter in the exhaust (e.g., the soluble organic fraction of soot) and reduce unburned hydrocarbons and CO in the exhaust to less environmentally harmful compounds. For example, the DOC element 30 can be structured to reduce hydrocarbon and CO concentrations in the exhaust to meet required emission standards for these components of the exhaust. An indirect consequence of the oxidation capabilities of the DOC element 30 is the ability of the DOC element 30 to oxidize NO to NO2. In this way, the amount 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 to NO by the DOC element 30.

[0051] In addition to treating the hydrocarbon and CO concentrations in the exhaust gas, the DOC element 30 can also be used in the controlled regeneration of the DPF element 40, the SCR catalyst element 50, and the AMOx catalyst element 60. This can be achieved by injecting or dosing unburned HC into the exhaust gas upstream of the DOC element 30. Upon contact with the DOC element 30, the unburned HC undergoes an exothermic oxidation reaction, resulting in an increase in the temperature of the exhaust gas exiting the DOC element 30 and subsequently entering the DPF element 40, the SCR catalyst element 50, and / or the AMOx catalyst element 60. The amount of unburned HC added to the exhaust gas is selected to achieve the desired temperature increase or target temperature of the controlled regeneration.

[0052] The DPF element 40 can be any of a variety of flow configurations and is structured to reduce particulate matter concentrations (e.g., soot and ash) in the exhaust gas to meet required emission standards. The DPF element 40 captures particulate matter and other constituents and can thus be periodically regenerated to burn off the captured constituents. Additionally, the DPF element 40 can be structured to oxidize NO to form NO2 independently of the DOC element 30.

[0053] As discussed above, the SCR system 52 includes a reductant delivery system. The reductant delivery system includes a reductant (e.g., DEF) source 54, a pump (not shown), and a doser 56 (e.g., sometimes referred to as a delivery mechanism 56). The reductant source 54 may be a container or tank capable of retaining a reductant, such as, for example, ammonia (NH3), DEF (e.g., urea), diesel oil, etc. The reductant source 54 is in reductant delivery communication with the pump, which is structured to pump reductant from the reductant source 54 via a reductant delivery line 58 to the delivery mechanism 56. The delivery mechanism 56 is positioned upstream of the SCR catalyst element 50. The feed mechanism 56 is selectively controllable to inject reductant directly into the exhaust stream prior to entry into the SCR catalyst element 50.As described herein, controller 100 is structured to control a timing and amount of reductant supplied to the exhaust gas, such as based on the estimated or calculated mass flow across each leg of exhaust aftertreatment system 22. The reductant may decompose to produce ammonia. As briefly described above, the ammonia reacts with NO in the presence of SCR catalyst element 50. x to the NO x to reduce less harmful emissions, such as N2 and H2O. The NO x in the exhaust stream contains NO2 and NO. Both NO2 and NO are reduced to N2 and H2O by various chemical reactions driven by the catalytic elements of the SCR catalyst element in the presence of NH3.

[0054] In some embodiments, the SCR catalyst element 50 is a vanadium-based catalyst element, and in other embodiments, the SCR catalyst element is a zeolite-based catalyst element, such as a copper zeolite (Cu-Ze) or an iron zeolite (Fe-Zu) catalyst element. In a representative embodiment, the reductant is aqueous urea, and the SCR catalyst element 50 is a zeolite-based catalyst element. In other embodiments, the reductant includes a first reductant and a second reductant, wherein the first reductant is urea and the second reductant is ammonia.

[0055] The AMOx catalyst element 60 may be any of a variety of flow-through catalyst elements structured to react with ammonia to produce primarily nitrogen. As briefly described above, the AMOx catalyst element 60 is structured to remove ammonia that has passed through or exited the SCR catalyst element 50 without contacting NO x in the exhaust gas. In certain cases, the aftertreatment system 22 may be operable with or without an AMOx catalyst element. Furthermore, although the AMOx catalyst element 60 may Fig. 1 as a separate unit from the SCR system 52, in some embodiments, the AMOx catalyst element may be integrated with the SCR catalyst element (e.g., the AMOx catalyst element and the SCR catalyst element may be located within the same housing). As referred to herein, the SCR catalyst element 50 and the AMOx catalyst element 60 form the SCR and AMOx system.

[0056] The system 10 (e.g., the aftertreatment system 22) includes various sensors. For example, the aftertreatment system 22 includes NO x-Sensors 12. The aftertreatment system 22 includes temperature sensors 14. The aftertreatment system 22 includes pressure sensors 16. The sensors may be strategically located throughout the aftertreatment system 22, such as upstream, at, or downstream of one or more catalysts (e.g., the DOC element 30, the DPF element 40, the SCR catalyst element 50, and / or the AMOx catalyst element 60). The sensors may be in communication with the controller 100 and configured to monitor operating conditions of the system 10. It is understood that one or more NO x -, pressure, temperature and a variety of other sensors (oxygen sensors, exhaust gas component sensors, NH3 sensors) are also included in the system and can be arranged at a variety of locations.

[0057] As shown, one or more pressure sensors 16 may be positioned upstream and downstream of the catalyst element(s). In this configuration, the pressure sensor 16 measures at least one of the outlet pressure, the inlet pressure, or the pressure at the catalyst element (e.g., pressure sensor 16 within the catalyst element (not shown)). For simplicity and for purposes of examples herein, the DPF element 40 may be provided as the catalyst element whose pressure data is monitored to estimate the mass flow or flow rate of exhaust gas. However, the pressure sensors 16 may be positioned upstream, downstream, or on other catalyst elements, such as, for example, the SCR catalyst element 50, the DOC element 30, or the AMOx catalyst element 60. The pressure data is used by the controller 100 to estimate the mass flow rate.

[0058] Furthermore, more than one NO xsensor must be positioned upstream and downstream of the catalyst element(s). In some configurations, a NO x -Sensor 12 the engine exhaust NO x , while another NO x -Sensor 12 the inlet NO x -amount of the SCR catalyst element 50. This is because the DOC element 30 / DPF element 40 may be removing some of the engine exhaust NO x oxidized, causing the engine exhaust NO x -Quantity not equal to the inlet NO x -amount of the SCR catalyst element 50. Accordingly, this configuration takes this possible discrepancy into account. The NO x -Amount leaving the SCR catalyst element 50 can be from a NO x -Sensor 12 downstream of the SCR catalyst element 50 and / or NO x-Sensor 12 downstream of the AMOx catalyst element 60. The NOx sensor 12 (in some embodiments, the NOx sensor 12) is positioned downstream of the SCR catalyst element 50 and is structured to detect the NOx concentration in the exhaust gas downstream of the SCR catalyst element (e.g., exiting the SCR catalyst element). The measurements (e.g., measured NO x -data) from NO x -Sensor 12 are used by the controller 100 to measure the NO x conversion efficiency across the respective train of the aftertreatment system 22. The NO x -Conversion efficiency corresponds to the amount of NO x , which is reduced via the one or more components of the aftertreatment system 22. Although a NO x -Sensor 12 at the outlet of the engine 20, respective NO x -Sensors 12 are provided upstream of the respective DOC element 30 or DPF element 40 of each branch.

[0059] Temperature sensors 14 are associated with one or more catalyst elements. Temperature sensors 14 are strategically positioned to sense the temperature of exhaust gas flowing into DOC element 30 (e.g., the temperature of the exhaust conduit upstream of the catalyst element), out of DOC element 30 (e.g., the temperature of the exhaust conduit downstream of the catalyst element), into another catalyst element (e.g., from DOC element 30 to DPF element 40), and out of DPF element 40 before being dosed with DEF by doser 56. In some embodiments, at least one temperature sensor 14 may be configured as part of the catalyst element itself, thereby directly measuring a bed temperature of the catalyst element.

[0060] The EGR system 70 is structured to recirculate exhaust gas back to an intake manifold of the engine 20 for use in combustion. The EGR system 70 includes an EGR cooler 74 and an EGR valve 76. The EGR cooler 74 may, for example, be an air-to-air and / or liquid (e.g., coolant)-to-air (e.g., exhaust gas) heat exchanger in some applications. The EGR cooler 74 is structured to remove heat from the exhaust gas before the exhaust gas is reintroduced into the intake manifold. Heat is removed from the exhaust gas before reintroduction to prevent, among other reasons, high intake temperatures that could promote pre-ignition (e.g., engine knock).

[0061] Although the exhaust aftertreatment system 22 is shown including the DOC element 30, the DPF element 40, the SCR catalyst element 50, and the AMOx catalyst element 60 positioned at specific locations relative to one another along the exhaust flow path, in other embodiments, the exhaust aftertreatment system may include more than one of the DOC element 30, the DPF element 40, the SCR catalyst element 50, and the AMOx catalyst element 60 positioned in one of various positions relative to one another along the exhaust flow path.

[0062] Fig. 1 is also shown as including an operator input / output (I / O) device 120. The operator I / O device 120 is communicatively coupled to the controller 100 so that information can be exchanged between the controller 100 and the I / O device 120. The information exchanged between the controller 100 and the I / O device 120 may relate to one or more components of Fig. 1 or any of the provisions of the controller 100 disclosed herein. The operator I / O device 120 enables an operator (e.g., occupant, etc.) of the vehicle to interact with the controller 100 and other components of the vehicle, such as the Fig. 1. For example, the operator I / O device 120 may include an interactive display, a touchscreen device, one or more buttons and switches, voice command receivers, etc. In some cases, the I / O device 120 may be part of a vehicle that includes the engine 20 and the aftertreatment system 22. In some other cases, the I / O device 120 may be a remote device that the operator can access, such as via a client device. In some aspects, the I / O device 120 may be a server that receives data from the controller 100 of the vehicle.

[0063] The controller 100 is structured to monitor the operations, conditions, or events within the system 10 (e.g., components of the aftertreatment system 22). The controller 100 is structured to, at least in part, 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 and among the components may occur 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 comparison, 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.The CAN bus includes any number of wired and wireless connections. Since the controller 100 communicates with the systems and components of . Fig. 1, the controller 100 is configured to receive data from one or more of the Fig. 1 shown components. For example, the data NO x -Data (e.g. an incoming NO x -Amount of NO x -Sensor 12 and an outgoing NO x -Amount of NO x-Sensor 12), dosing data (e.g., timing and amount of dosing delivered by doser 56), and vehicle operating 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 in more detail herein, using this data, controller 100 monitors multi-train aftertreatment system 22 to determine if a restriction is causing an imbalance in the flow distribution across individual trains and to diagnose the imbalance, such as to detect reductant slip and NO x -Slip and optimize the regeneration control or regeneration trigger. The structure, function, or configuration of the controller 100 is described with respect to Fig. 2 further described.

[0064] Fig. Figure 2 shows an exemplary structure for the controller 100, which includes a processing circuit 101 including a processor 102, a memory 103, and various circuits including at least a motor circuit 105, an ammonia circuit 106, a NO xCircuit 107, a flow rate circuit 108, a correction circuit 109, a modeling circuit 110, and an adjustment circuit 111. 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. Memory 103 (e.g., RAM, ROM, flash memory, hard disk storage, etc.) may store data and / or computer code to facilitate the various processes described herein. Memory 103 may be communicatively coupled to processor 102 and one or more circuits. In various embodiments, memory 103 includes motor circuit 105, ammonia circuit 106, NO xCircuit 107, flow rate circuit 108, correction circuit 109, modeling circuit 110, and adjustment circuit 111. Memory 103 is configured to provide computer code or instructions to processor 102 for performing the processes described herein with respect to controller 100. Furthermore, memory 103 may be or include tangible, non-transitory volatile memory or non-volatile memory. Accordingly, memory 103 may include database components, object code components, script components, or any other type of information structure for supporting the various activities and information structures described herein.

[0065] The controller 100 includes a communications interface 104. The communications interface 104 may include any combination of wired and / or wireless interfaces (e.g., jacks, antennas, transmitters, receivers, transceivers, wired connectors) for performing data communication with various systems, devices, or networks structured to enable in-vehicle communication (e.g., between and among components of the vehicle) and out-of-vehicle communication (e.g., directly with a remote computing system). In this regard, in some embodiments, the communications 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 the connection of the controller 100 to the network.The network interface includes any combination of a wireless network transceiver (e.g., a cellular modem, a Bluetooth transceiver, a Wi-Fi transceiver) and / or a wired network transceiver (e.g., an Ethernet transceiver). In some arrangements, the network interface includes the hardware and machine-readable media sufficient to support communication over multiple channels of data communication. Further, in some arrangements, the network interface includes cryptographic capabilities to establish a secure or relatively secure communication session in which data communicated over the session is encrypted.For example, and with respect to off-vehicle / system communication, the communication interface 104 may include an Ethernet card and an Ethernet port for sending 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 structured to communicate over local area networks and / or wide area networks (e.g., the Internet) and may utilize a variety of communication protocols (e.g., IP, LON, Bluetooth, ZigBee, and radio, cellular, near field communication). Further, the communication interface 104 may operate in conjunction or in tandem with a telematics unit, if included, to communicate with other vehicles in the fleet and / or the remote computing system.

[0066] The controller 100 is structured to receive inputs (e.g., signals, information, data, etc.) from the components / systems of the system 10 and / or the operator I / O device 120. Thus, the controller 100 is structured to at least partially control the components / systems of the system 10 and the associated motor 20. Since the components of Fig. 2 may be embodied in a vehicle, the controller 100 may be configured as one or more electronic control units (ECUs). The controller 100 may be separate from or included within 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, the 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 the system 10.

[0067] In one configuration, one or more of the motor circuit 105, the ammonia circuit 106, the NO xCircuit 107, flow rate circuit 108, correction circuit 109, modeling circuit 110, or adjustment circuit 111 may be embodied as machine- or computer-readable media storing instructions executable by a processor, such as processor 102, and stored in a storage device, such as memory 103. As described herein and among other uses, the machine-readable media facilitates the performance of certain operations to enable the reception and transmission of data. For example, the machine-readable media may provide an instruction (e.g., a command, etc.) to, for example, acquire data. In this regard, the machine-readable media may include programmable logic that defines the frequency of acquiring the data (or transmitting the data).The computer-readable media may include code written in any programming language, including, but not limited to, Java or the like, and any conventional procedural programming languages, such as 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 interconnected by any type of network (e.g., CAN bus, etc.).

[0068] In another configuration, the one or more circuits are embodied as hardware units, such as electronic control units. For example, the one or more circuits may be embodied as one or more circuit components, including, but not limited to, processing circuits, network interfaces, peripheral devices, input devices, output devices, sensors, etc. In some embodiments, the 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-a-chip (SOCs) circuits, microcontrollers, etc.), telecommunications circuits, hybrid circuits, and any other type of "circuitry." The one or more circuits may be any type of component for achieving or facilitating the achievement of the operations described herein.For example, a circuit as 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. The one or more circuits may also include programmable hardware devices, such as field-programmable gate arrays, programmable array logic, programmable logic devices, or the like. The one or more circuits may include one or more memory devices for storing instructions executed by the processor(s) of the individual circuits (e.g., motor circuit 105, ammonia circuit 106, NO. x-circuit 107, flow rate circuit 108, correction circuit 109, modeling circuit 110, and adjustment circuit 111). The one or more memory devices and processor(s) may have the same definition as provided below with respect to memory 103 and processor 102. In some hardware unit configurations, the one or more circuits may be geographically distributed across separate locations in, for example, a vehicle. Alternatively, and as shown, the one or more circuits may be implemented in or within a single unit / housing, shown as controller 100.

[0069] In the example shown, the controller 100 includes the processing circuit 101, which includes a motor circuit 105, an ammonia circuit 106, a NO xcircuit 107, a flow rate circuit 108, a correction circuit 109, a modeling circuit 110, and an adjustment circuit 111. The processing circuit 101 may be structured or configured to execute or implement the instructions, commands, and / or control processes described herein with respect to the one or more circuits. The illustrated configuration provides a motor circuit 105, an ammonia circuit 106, a NO xcircuit 107, a flow rate circuit 108, a correction circuit 109, a modeling circuit 110, and an adjustment circuit 111 as instructions in machine- or computer-readable media. In some embodiments, the instructions may be stored by the storage device. However, as mentioned above, this illustration is not intended to be limiting, as the present disclosure contemplates other embodiments in which the motor circuit 105, the ammonia circuit 106, the NO x Circuit 107, flow rate circuit 108, correction circuit 109, modeling circuit 110, and adjustment circuit 111, or at least one of the one or more circuits, is configured as a hardware unit. All such combinations and variations are intended to be within the scope of the present disclosure.

[0070] In the example shown, the controller 100 includes at least the engine circuit 105 structured to control the engine 20, an ammonia circuit 106 in communication with sensors associated with the SCR catalyst element 50 and / or the AMOx catalyst element 60, a NO x -Circuit 107 in communication with the NO xsensors 12, a flow rate circuit 108 in communication with the pressure sensors 16 to estimate the mass flow across the aftertreatment system 22, a correction circuit 109 configured to calculate and apply a correction factor to the estimated mass flow, a modeling circuit 110 in communication with other circuits and configured to manage models related to the predefined flow and their respective correction factors to be used by the correction circuit 109, and an adjustment circuit 111 in communication with the other circuits and configured to adjust at least one of the reductant dosing control, hydrocarbon control, or soot loading estimation based on the correction factor applied, for example, to the estimated mass flow.

[0071] The engine circuit 105 is structured to receive information from a user or operator (e.g., via the operator input / output device 120) and to provide instructions to the engine 20 or otherwise control it. For example, the engine circuit 105 may control the operations or components of the engine, including at least the intake valve for controlling intake air or gas, the exhaust valve for releasing the exhaust gas through the pipe (e.g., pipe 24, 28A-F, 26, etc.), or other components of the engine 20. Thus, the engine circuit 105 may control a torque and / or a speed of the engine 20. The engine circuit 105 is structured to receive information associated with the engine 20, such as a fuel quantity, a temperature, etc. The engine circuit 105 is structured to provide the engine information to one or more other circuits (e.g., the ammonia circuit 106, the NO xcircuit 107, the flow rate circuit 108, the correction circuit 109, the modeling circuit 110 and the setting circuit 111, etc.) of the controller 100 and to components of the memory 103.

[0072] The ammonia circuit 106 is configured to communicate with the doser 56, the temperature sensors 14 and the NO x-Sensors 12 to determine the amount of ammonia (or reductant) stored, for example, in the SCR catalyst element 50. In some cases, the ammonia circuit 106 is configured to control the doser 56 to supply or introduce reductant into the conduit. In this case, the ammonia circuit 106 is configured to determine the reductant dosing rate, including the duration, frequency, and timing. Thus, the ammonia circuit 106 can determine the amount of reductant stored in the SCR catalyst element 50 using at least one of the reductant dosing rate and data from one or more other circuits, such as the amount of NO x at the inlet of the SCR catalyst element 50 and the amount of NO x at the outlet of the SCR catalyst element 50 (e.g. amount of NO xwhich is converted via the catalyst element) and / or the mass flow in the respective strand.

[0073] The NO x -Circuit 107 is connected to the NO x -Sensors 12 coupled and communicates with them and provides information regarding NO x levels to other circuits of the controller 100 and to components of the memory 103. The one or more NO x -Sensor(s) can be a virtual NO x -Sensor(s) or (a) physical NO x -Sensor(s). The NO x -Circuit 107 can receive raw data from the NO x -Sensors 12 are received, in addition to other sensor data, to process information that has a NO x -level, to other circuits of the controller 100 and to components of the memory 103.

[0074] The flow rate circuit 108 is coupled to and communicates with the pressure sensors 16 and provides information regarding the magnitude of the pressure or other pressure data to other circuits of the controller 100 and to components of the memory 103. The one or more pressure sensors may be virtual pressure sensors or physical pressure sensors. The flow rate circuit 108 may process raw data received from the pressure sensors 16, in addition to other sensor data, to provide information indicative of a pressure level to other circuits of the controller 100 and to components of the memory 103. Using the pressure data, the flow rate circuit 108 is configured to estimate a mass flow rate at the locations corresponding, for example, to the pressure sensors 16.

[0075] The correction circuit 109 is configured to communicate with other circuits, including receiving data from at least one of the NO x -Circuit 107 (e.g. NO x-measurements) or the flow rate circuit 108 (e.g., pressure data or mass flow data). The correction circuit 109 is configured to calculate a correction factor (e.g., sometimes referred to as an adjustment factor) to adjust the estimated mass flow estimated based on the pressure data. For example, the correction circuit 109 is configured to receive estimates of the mass flow across individual branches of the aftertreatment system 22. The correction circuit 109 is configured to identify a flow split imbalance due to a restriction when the estimated total mass flow across the branches is not within the range of the engine exhaust mass flow.If an imbalance or inaccuracy exists in the estimated mass flow, the correction circuit 109 is configured to use the techniques and processes described herein to calculate the correction factor to calibrate or diagnose the estimated mass flows. In various embodiments, the correction circuit 109 is configured to account for SCR deposition (e.g., whether to perform regeneration), a newly installed system, and a balanced flow split due to accumulated soot loading.

[0076] The modeling circuit 110 is configured to manage models representative of predefined flow distributions 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 adapt the model in light of any updated information from the operator I / O device 120. The flow splits associated with each model may be predefined, such as 50-50 (e.g., 50% of the engine exhaust mass flow via the first branch 22A and 50% of the exhaust mass flow via the second branch 22B), 65-35 (e.g., 65% via the first branch 22A and 35% via the second branch 22B), 55-45 (e.g., 55% via the first branch 22A and 45% via the second branch 22B), etc.Each model corresponding to a predefined flow split may be associated with a respective correction factor (e.g., predetermined for the respective flow split and pressure data). The correction factor may be a multiplier, percentage, or amount of mass flow to increase or decrease the estimated mass flow for at least one of the strands based on the flow split estimate. The modeling circuit 110 is configured to compare the pressure data (e.g., catalyst outlet pressure or pressure differential across the catalyst element) representative of the estimated flow split with the various models over time. The modeling circuit 110 is configured to select at least one of the models with a predefined flow split similar to the estimated flow split.The modeling circuit 110 is configured to communicate or provide a correction factor of the selected model to the correction circuit 109 for adjusting the estimated mass flows.

[0077] The adjustment circuit 111 is configured to communicate with other circuits, including the ammonia circuit 106, the NO x circuit 107, the flow rate circuit 108, the correction circuit 109, etc. The adjustment circuit 111 communicates with the other circuits to obtain information, including at least one of the NO x -Conversion efficiency, mass flow estimates, amount of stored reductant (e.g. ammonia), NO produced by the engine x , the amount of NO xin each train, the correction factor, etc. In some cases, the adjustment circuit 111 communicates directly with the components of the systems, including the sensors, the doser 56, or others. Using the information obtained from the system, the adjustment circuit 111 is configured to adjust at least one of the estimated mass flow by applying the correction factor, the reductant dosing rate, the hydrocarbon injection (e.g., regeneration) timing, or the soot loading estimate. The adjustments to the dosing rate, the regeneration timing, or the soot loading estimate are based at least in part on the adjusted estimated mass flow, which represents the amount of exhaust byproducts traversing the trains of the aftertreatment system 22.As described herein, the one or more circuits of controller 100 are configured to detect and diagnose an imbalance within aftertreatment system 22.

[0078] With reference to Fig. 3, an example graph 300 is shown illustrating a correlation between mass flow split errors relative to the restriction difference between the branches. The x-axis may represent the branch-to-branch restriction difference (e.g., the ratio of restriction in one branch compared to another branch or tailpipe pressure drop delta at a given nominal flow rate) and the y-axis may represent the degree of error in the mass flow split ratio. For example, in certain systems, there may be a restriction at a tailpipe outlet of the system. In such systems, an increase in the restriction difference between the branches (e.g., one branch has more restriction than the other) may result in a larger error in the flow split ratio (e.g., error in the estimation of the mass flow between the branches). As shown, the increase in error (e.g.,The increase in the delta value from zero should be proportional to the increase in the restriction difference (e.g., an increase in the leg-to-leg tailpipe pressure drop delta). The increase in error represents a deterioration in the accuracy of the determined mass flow split ratio. In this case, as the value in the y-axis of graph 300 decreases (e.g., accuracy decreases or error increases), more NH3 is slipping from the tailpipe, as described in conjunction with . Fig. 4 shown.

[0079] With reference to Fig. 4, an exemplary graph 400 is shown illustrating a correlation between ammonia slip relative to the restriction difference between the strings. The x-axis may represent the string-to-string restriction difference (e.g., tailpipe pressure drop delta at a given nominal flow rate) and the y-axis may represent the difference in the amount of ammonia slip between the strings (e.g., string-to-string delta). The higher value in the y-axis represents more ammonia slip occurring from at least one of the strings. Further, in such Fig. 3, due to an increase in the restriction difference, the systems experience an increase in reductant slip. For example, the restriction difference may cause the particular systems to overestimate the mass flow passing through at least one of the trains. Therefore, the systems may increase the reductant dosing rate if the estimated mass flow does not represent the actual mass flow, thereby causing an overdose of the reductant. In some other cases, the restriction difference may cause the systems to underestimate the mass flow across at least one of the trains. In such cases, the systems may underdose the train, causing an increase in NO x-slip. Therefore, the systems and methods configure the controller 100 to detect the imbalance caused by restrictions in at least one of the trains and diagnose the imbalance to at least one of the reductant slip or NO x -Slip. As shown, an increase in ammonia slip is proportional to an increase in the restriction differential (e.g., an increase in the string-to-string tailpipe pressure drop delta).

[0080] With reference to Fig. 5 illustrates an example graph 500 of collected data, including pressure signatures or measurements, when a restriction is located upstream of the catalyst outlet of the second branch 22B (e.g., upstream of the pressure sensor 16 at an outlet of the catalyst element). The y-axis represents the pressure readings (e.g., delta pressure reading across a particular catalyst element) relative to the x-axis, which represents the total mass flow from the engine 20 (e.g., referred to as an exhaust mass flow). The mass flow is measured in actual cubic meters per second (ACMS). In this case, the restriction may be caused by an inlet pipe to an aftertreatment system, such as a misalignment or obstruction, or within the catalyst element (e.g., soot loading differences between the two branches). Due to the restriction, this system may experience an imbalance in mass flow, as shown in Fig. 5. For example, the data points (e.g., output data points) labeled as 0% in the legend represent the pressure measurements of a balanced system. The balanced system refers to a system with a 50-50 flow split across the legs of the aftertreatment system 22. With a constraint upstream of the pressure sensor 16, the data points related to the leg having a higher mass flow (e.g., labeled as 60%) are shown to be above the balanced data points, representing relatively higher pressure readings. Further, the data points related to the leg having a lower mass flow (e.g., labeled as "low flow leg") are shown to be below the balanced data points, representing relatively lower pressure readings. In this case, at 60% intake valve position, the flow split is 55-45 (or 55% or 45%, respectively), where 55% (e.g.,(indicated in the legend) of the exhaust mass flow passes through the high-flow branch and 45% of the exhaust mass flow passes through the low-flow branch. Thus, such characteristics of the high-flow branch and the low-flow branch represent that the restriction is located upstream of the pressure sensor 16. If there is a restriction upstream of the pressure sensor position (e.g., measuring the pressure at the outlet of the DPF element 40), the sum of the individual branch mass flows is equal to or approximately equal to the engine exhaust mass flow.

[0081] The valve position can be adjusted to mimic different tailpipe or inlet pipe asymmetries in a test cell (e.g., to adjust, manage, or control the symmetries between branches). The valve position can be used to avoid the need to manufacture different tailpipes for each branch or to find the space of a standard test cell size to fit the different tailpipes, for example. In the examples discussed above, the 60% inlet valve position corresponds to holding a second branch (branch 2) inlet valve (valve 2) in a 60% closed position while leaving all other valves open (0% closed position), resulting in 55% flow in a first branch (branch 1) and 45% flow in branch 2.In some cases, the 90% exhaust valve position corresponds to holding the leg 2 exhaust valve (valve 4) in a 90% closed position while all other valves are open (0% closed position), resulting in 60% flow on leg 1 and 40% flow on leg 2. For example, the 60% inlet valve position may correspond to a certain length of additional pipe or tube bends on the inlet side of leg 2 compared to leg 1. Similarly, the 90% on the outlet side may correspond to a certain length of additional pipe or tube bends on leg 2 on the outlet side compared to the leg 1 outlet, causing the restriction or differences in flow between the first and second legs.

[0082] With reference to Fig. 6 illustrates an exemplary diagram 600 of collected data including pressure signatures or measurements when a restriction is located downstream of the catalyst outlet of the second branch 22B (e.g., downstream of the pressure sensor 16 at the outlet of the catalyst element). As shown, similar to Fig. 5 shows the output data points in the graph (e.g., labeled as 0% in the legend) that indicate pressure signatures for a balanced system. The x-axis and y-axis of graph 600 are similar to the x-axis and y-axis of graph 500. In some cases, the restriction is located downstream of the pressure sensor 16 of the second leg 22B. As shown, the pressure measurements for the first leg 22A and the second leg 22B (e.g., with 90% exhaust valve position (labeled in the legend), representing 60-40 flow split) are above the output data points, indicating that the restriction is located downstream of the pressure sensor 16. Consequently, for restrictions downstream of the pressure sensor 16, the pressure signatures collected by the pressure sensor 16 are higher than the output data for both the high flow leg and the low flow leg (e.g.,reversed pressure signature for the low leg, as shown in section 602).

[0083] In the case of a restriction upstream of the pressure sensor 16 used to estimate the mass flow, the system may not require a correction / adjustment factor to correct / adjust the estimated mass flow. However, in the case of 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 mass flow imbalance (e.g., overestimated and / or underestimated mass flows).

[0084] With reference to Fig. Figure 7 illustrates an exemplary overview process flow diagram for a process 700 for managing mass flow splitting in a multi-train aftertreatment system using pressure information. The processes, operations, or steps of Fig. 7 may be performed by the components (e.g., controller 100, I / O device 120, aftertreatment system 22, sensors, etc.) of system 10, data processing system, cloud computing environment, or any other computing devices described herein in connection with the Fig. 1-6. 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 components of aftertreatment system 22, such as one or more sensors, and forwarding the data to the remote device for processing, or vice versa.

[0085] At step 702, the controller 100 (e.g., the flow circuit 108) is configured to estimate a first mass flow of exhaust gas in the first branch 22A. The first mass flow of exhaust gas may be estimated based on pressure data from pressure sensors 16 of the first branch 22A, such as catalyst outlet pressure or pressure differential across the catalyst element (e.g., a first DPF element).

[0086] At step 704, the controller 100 (e.g., the flow circuit 108) is configured to estimate a second mass flow of exhaust gas in the second branch 22B. The second mass flow of exhaust gas may be estimated based on pressure data from pressure sensors 16 of the second branch 22B, such as catalyst outlet pressure or pressure differential across the catalyst element (e.g., a second DPF element).

[0087] At step 706, the controller 100 (e.g., the flow circuit 108) is configured to calculate an estimated total mass flow based on the estimated first mass flow and the estimated second mass flow. The controller 100 may calculate the estimated total mass flow by summing the estimated first mass flow and the estimated second mass flow. In various embodiments, the controller 100 is configured to calculate the estimated total mass flow using other means, processes, or techniques.

[0088] At step 708, the controller 100 (e.g., the flow circuit 108) determines that the estimated total mass flow is greater than an engine exhaust mass flow. The engine exhaust mass flow corresponds to the total mass flow at the outlet of the engine 20. In response to determining that the estimated total mass flow is greater than the engine exhaust mass flow, the controller 100 (e.g., the correction circuit 109) is configured to calculate a correction factor to compensate for the estimated first mass flow and the estimated second mass flow. Compensating for the estimated first mass flow and the estimated second mass flow may refer to correcting at least one of the mass flows such that the sum of the estimated mass flows is at or around (e.g., within 5%, 3%, etc. deviation from) the engine exhaust mass flow or within a predetermined threshold / range of the engine exhaust mass flow.The fact that the estimated total mass flows are at or around the engine outlet indicates that the estimated mass flow of each leg is accurate.

[0089] At step 710, the controller 100 (e.g., the flow circuit 108 or the correction circuit 109) is configured to estimate a corrected first mass flow of the exhaust gas in the first branch 22A and a corrected second mass flow of the exhaust gas in the second branch 22B using the correction factor. The controller 100 is configured to apply the correction factor to the estimated mass flow of each branch to increase or decrease the estimated mass flow. In some cases, the correction factor indicates a ratio of the engine exhaust mass flow received by each of the branches. In this case, the controller 100 is configured to apply the correction factor to the engine exhaust mass flow to estimate the corrected first mass flow and the corrected second mass flow based on the ratio.

[0090] At step 712, the controller 100 (e.g., the adjustment circuit 111) is configured to adjust at least one of a reductant dosage, hydrocarbon dosage, or soot loading estimate based on the corrected first mass flow and the corrected second mass flow. An increase from the estimated mass flow to the corrected mass flow may result in at least one of an increase in the reductant dosage, an advance in the timing or frequency of the hydrocarbon dosage, or an increase in the soot loading estimate due to the increase in exhaust byproducts in the train.A reduction from the estimated mass flow to the corrected mass flow may result in at least one of a reduction in reductant dosing, a delay in the timing or frequency of hydrocarbon dosing, or a reduction in the soot loading estimate due to the reduction in exhaust byproducts in the train. In various arrangements, the acts, techniques, or features of process 700 may be used in conjunction with. Fig. 8 will be described in more detail.

[0091] With reference to Fig. 8 is an exemplary process flow diagram for performing an exemplary proportional correction process 800 of Fig. 7 in a multi-line post-treatment system using pressure information. The processes, operations or steps of Fig. 8 may be performed by the components (e.g., controller 100, I / O device 120, aftertreatment system 22, sensors, etc.) of system 10, data processing system, cloud computing environment, or any other computing devices described herein in connection with the Fig. 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 components of aftertreatment system 22, such as one or more sensors, and forwarding the data to the remote device for processing, or vice versa.

[0092] The process 800 begins at step 802. For example, at step 802, the controller 100 may receive a command or indication to initiate an operation to monitor and diagnose imbalanced flow sharing within the system 10. The controller 100 receives the command from the I / O device 120 or other remote devices via the communication interface 104. In some cases, the controller 100 initiates the process 800 in response to receiving an indication (e.g., from another processing device) that there is a restriction within the system, such as a restriction downstream of the pressure sensors 16 used to estimate mass flow.

[0093] At step 804, the controller 100 (e.g., the flow circuit 108) estimates or calculates the mass flow of each branch (e.g., the first branch 22A and / or the second branch 22B) of the aftertreatment system 22. Each branch includes one or more components of the aftertreatment system 22. For each branch, the flow circuit 108 estimates the mass flow based on pressure information associated with a catalyst element (e.g., the DPF element 40 or other catalyst elements). The pressure information includes at least one of catalyst outlet pressure (e.g., DPF outlet pressure) or delta pressure (e.g., pressure differential / difference across the DPF element 40 or the difference between pressure at the inlet and pressure at the outlet of the DPF element 40). The flow circuit 108 may use the following equation / formula to estimate the mass flow based on pressure data: m˙=k2ρΔPk=A / ⌊4f(L / dch)+Kin+Kout⌋ A = open front surface of the SCR catalyst element 50 or of the catalyst element following the DPF element 40. ṁ = mass flow k = flow coefficient ρ = density Δ = delta P = pressure

[0094] In some cases, the flow rate circuit 108 is configured to use the following simplified model to calculate the mass flow: m˙=k2ρΔPΔP=DPF OutP−AmbP k = flow coefficient, which can be implemented as a lookup table DPF = DPF element 40 (e.g. other catalyst elements can be used) OutP = pressure at the outlet of the catalyst element AmbP = ambient pressure or pressure surrounding the catalyst element

[0095] The flow circuit 108 calculates the density (rho) as follows: ρ=PBedRTBed P Bett = Bed pressure of the catalyst element R = ideal gas constant T' Bett = bed temperature of the catalyst element

[0096] To iteratively converge this ṁ to its true value, the flow circuit 108 uses a conversion technique (e.g., Newton-Raphson method) to calculate the estimated mass flow for a respective branch: f(m˙)=m˙−k2ρΔP f1(m˙)=1 m˙esti+1=m˙esti−f(m˙esti)f1(m˙esti), where i = 0,1,2,3 ṁ est = estimated mass flow

[0097] An acceptable or desired range of flow accuracy (e.g., differences between the mass flow from one train to another) is + / - 2% or + / - 3% above or below the minimum mass flow (e.g., total engine flow of 24 kg / min, 18 kg / min, etc.). In response to the degradation of the accuracy for estimating the flow split between the trains, such as due to noise or restriction downstream of the one or more sensors 16, the flow circuit 108 is configured to use the equations to estimate the correction factor.

[0098] The flow circuit 108 uses the estimated mass flow to identify the mass flow in one leg relative to the other, thereby normalizing the modeling errors of the mass flow calculation. Based on the above equations, the flow circuit 108 may estimate the mass flow in each leg (e.g., a first mass flow of exhaust gas in the first leg 22A and a second mass flow of exhaust gas in the second leg 22B) based on at least one of catalyst outlet pressure or pressure differential across the catalyst element. In some embodiments, the flow circuit 108 is configured to use other equations to estimate the mass flow in the system.

[0099] The flow circuit 108 calculates a (e.g., estimated) total mass flow based on the estimated mass flows of the branches. For simplicity, the estimated total mass flow corresponds to the sum of the estimated mass flows at a particular time 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) is above a threshold (e.g., 0.3 ACMS, 0.4 ACMS, 0.5 ACMS, etc.) or when the pressure at the outlet of the engine 20 is above a threshold (e.g., 4 kPa, 6 kPa, 8 kPa, etc.). A higher engine exhaust mass flow may reflect a higher delta between the estimated total mass flow and the engine exhaust mass flow, which can be used to identify an inaccuracy in the estimated mass flow based on pressure information.The engine exhaust mass flow refers to the mass flow measured at the exhaust pipe of the engine 20 upstream of the branches.

[0100] At step 806, the controller 100 (e.g., the flow circuit 108) determines whether the total mass flow of the branches is greater than or above the engine exhaust mass flow. In some cases, the controller 100 determines whether the total mass flow of the branches is greater than the engine exhaust mass flow by at least a predetermined value (e.g., percentage or predetermined rate). If the estimated total mass flow is above the engine exhaust mass flow, the process 800 proceeds to step 810. The estimated total mass flow being greater than the engine exhaust mass flow reflects an imbalance in the flow split with the restriction downstream of the pressure sensor 16 used to estimate the mass flow. In this case, the estimated mass flow for at least one of the branches is inaccurate. Otherwise, if the estimated total mass flow is at or below the engine exhaust mass flow, the process 800 proceeds to step 808.

[0101] The total mass flow may be less than the engine exhaust mass flow in cases where the mass flow escapes or slips from certain connections of the aftertreatment system 22, thereby reducing the total mass flow. In some embodiments, if the total mass flow is less than a predefined threshold (e.g., less than 80%, 90%, etc., of the expected total mass flow), the controller 100 may initiate a silent fault to notify the operator via the operator I / O device 102 or transmit a signal to the service technician (e.g., inform the service technician), such as to check for leaks during the next maintenance event for the system 10.

[0102] At step 808, the controller 100 (e.g., correction circuit 109) determines that no correction factor is required for the flow split based on the estimated total mass flow being at or below the engine exhaust mass flow. The estimated total mass flow being at or below the engine exhaust mass flow reflects either a balanced flow split or an imbalance in the flow split with the restriction upstream of the pressure sensor 16 used to estimate the mass flow. Therefore, even if the flow split is unbalanced, the estimated mass flow of each leg is accurately estimated, and the controller 100 (e.g., adjustment circuit 111) can adjust the reductant dosing rate, control the hydrocarbon injection, and / or the soot loading estimation accordingly.

[0103] At step 810, the controller 100 (e.g., the tuning circuit 111) determines whether the SCR catalyst element 50 has been regenerated (e.g., whether regeneration is being performed or is in progress for the SCR catalyst element 50). If regeneration has not been completed, the controller 100 (e.g., the tuning circuit 111) initiates or continues regeneration of the SCR catalyst element 50 at step 812. The regeneration process removes deposits or catalyst-deactivated compounds (e.g., potential restrictions) and restores the SCR catalyst element 50 to a predefined activity level. The controller 100 activates the regeneration process because the imbalance may be caused by deposits in the SCR catalyst element 50 of either the first or second train 22AB.

[0104] In various embodiments, the controller 100 initiates hydrocarbon dosing to regenerate at least one of a first SCR catalyst element of the first train 22A and / or the second SCR catalyst element of the second train 22B 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. In some cases, the controller 100 receives an indication of whether individual SCR catalyst elements 50 have been regenerated. Accordingly, the controller 100 initiates hydrocarbon dosing to regenerate at least one of the SCR catalyst elements 50 that was not or is not in the regeneration process. In some cases, the controller 100 initiates hydrocarbon dosing as part of the beginning of the process 800, such as at step 802. When the regeneration is complete, the process 800 proceeds to step 814.

[0105] At step 814, the controller 100 (e.g., the flow circuit 108) determines, similar to step 806, whether the estimated total mass flow after performing regeneration is greater than the engine exhaust mass flow. For example, following regenerating at least one of the SCR catalyst elements 50 in the respective branches of the aftertreatment system 22, the controller 100 estimates a third mass flow of exhaust gas in the first branch 22A and a fourth mass flow of exhaust gas in the second branch 22B (e.g., calculated similarly to step 804). Using the third and fourth mass flows, the controller 100 calculates the (e.g., second) estimated total mass flow to compare to the engine exhaust mass flow. The estimated total mass flow may be similar to the above total mass flow. If the estimated total mass flow is still greater than the engine exhaust mass flow, process 800 proceeds to step 818.

[0106] Otherwise, if the estimated total mass flow is at or below the engine exhaust mass flow, process 800 proceeds to step 816. Similar to step 808, at step 816, controller 100 may not apply a correction factor to the estimated flow split because the regeneration event resolves the imbalance between the strands (e.g., an imbalance caused by SCR catalyst element 50), making the estimated total mass flow equal to, for example, the engine exhaust mass flow. As described herein, 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 pressure information because the restriction occurred downstream of pressure sensor 16.

[0107] At step 818, the controller 100 determines whether the system (e.g., the aftertreatment system 22 or at least one of the trains or components of the trains of the aftertreatment system 22) is newly installed. The controller 100 determines whether the system is newly installed in response to the estimated total mass flow being greater than the engine exhaust mass flow associated with at least one of steps 706 or 714. In some cases, the controller 100 determines whether the system is newly installed at the beginning of process 800 (at step 802). In some other cases, the controller 100 determines whether the system is newly installed after the regeneration event is completed at step 810. If the system is newly installed, the process 800 proceeds to step 820. The presence of a newly installed system (e.g., a system with relatively low engine hours, such as less than 50 hours, 100 hours, etc.) may indicate that the restriction is caused by the original equipment manufacturer (OEM) piping system or is not caused by soot buildup or SCR deposition, considering that the one or more components of the aftertreatment system 22 are also newly installed. In this case, newly installed systems with certain restrictions are due to piping differences in the systems. A system that is no longer considered a new system (e.g., engine hours are greater than or equal to a predefined threshold) may have different restrictions between strands due to accumulated ash or soot or deposit formation in certain component(s) of the aftertreatment system 22, such as soot buildup in the DPF element 40 or deposit formation in the SCR catalyst element 50 of one strand compared to the other.

[0108] At step 820, the controller 100 (e.g., the correction circuit 109) calculates a correction factor in response to determining that the first branch 22A or the second branch 22B is newly installed. The controller 100 calculates the correction factor for a newly installed system by performing a proportionality correction for the estimated mass flow based on the calculated ACMS value of the catalyst outlet pressure. To perform the proportionality correction, the process 800 proceeds to step 828.

[0109] At step 828, the controller 100 (e.g., the correction circuit 109) determines pressure differential values ​​across the first SCR catalyst element in the first branch 22A and the second SCR catalyst element in the second branch 22B. The pressure differential value represents a 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 a first pressure differential value in the first branch 22A and a second pressure differential value in the second branch 22B.

[0110] At step 830, the controller 100 (e.g., 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 a flow split between the branches. For example, based on the ratio between the two branches, the controller 100 may determine, using the pressure difference values, which of the branches is the low-flow branch (e.g., the branch with a relatively lower mass flow) and the high-flow branch (e.g., the branch with a relatively higher mass flow). The branch corresponding to a higher pressure difference value may represent the high-flow branch, and the branch corresponding to a lower pressure difference value may represent the low-flow branch.For example, if there is a relatively higher restriction downstream of the pressure sensor, such as in the first leg compared to the second leg, the pressure sensor in the first leg may measure a higher backpressure induced by the higher restriction downstream of the pressure sensor in the first leg compared to the second leg. In another example, if there is a relatively higher restriction upstream of the pressure sensor in one leg compared to another, such as in the first leg compared to the second leg (e.g., with no downstream pressure differential in this case), the pressure sensor may sense a higher pressure when there is a higher mass flow in the first leg. However, because there is a relatively stronger upstream restriction in the first leg than in the second leg, the mass flow in the first leg is lower than the mass flow in the second leg, and the pressure sensor may sense a lower pressure on the first leg.

[0111] In various embodiments, the correction factor is a multiplier based on the ratio between the pressure difference 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. Using a ratio (or mass flow split) of 60-40 as an example, the controller 100 is configured to estimate a corrected mass flow for the low-flow leg by applying the correction factor (e.g., the lower ratio, such as 40% in this case) to the engine exhaust mass flow (e.g., 40% of the engine exhaust mass flow). In some cases, the controller 100 is configured to estimate a corrected mass flow for the high flow leg by applying the correction factor (e.g., the higher ratio, such as 60% in this case) to the engine exhaust mass flow (e.g., 60% of the engine exhaust mass flow).Accordingly, the controller 100 may estimate the corrected mass flow for each of the branches based on the relationship between the pressure difference values. The operations for calculating and applying the correction factor based on the relationship between pressure differences may, for example, be performed in conjunction with at least one of the following: Fig. 8 will be described in more detail.

[0112] Referring again to step 818, the controller 100 may receive or determine an indication that neither the first nor the second strand 22A-B nor any components therein are reinstalled. If the system is not reinstalled, the process 800 proceeds to step 822.

[0113] At step 822, the controller 100 (e.g., circuit 108) determines whether soot loading flow balancing has occurred or is true. Soot loading flow balancing refers to the accumulation of soot in the catalyst elements (e.g., the first catalyst element in the first leg 22A and the second catalyst element in the second leg 22B) over time, causing the mass flow split to equalize. For example, there may be an imbalanced flow split in the system while soot loading is low. Because soot accumulates faster in the high current leg (e.g., more soot traversing the high current leg) and slower in the low current leg (e.g., less soot traversing the low current leg), the high current leg builds up more soot loading compared to the low current leg.Over time, soot loading causes a restriction in the high current leg comparable to the existing restriction in the low current leg, thereby equalizing the current split between the legs of the aftertreatment system 22. Therefore, the controller 100 is configured to monitor the current split and soot loading over time to determine whether the current split has been equalized by the soot loading accumulation.

[0114] The controller 100 determines whether the soot flow compensation occurred after determining that the system is not newly installed at step 818. In some cases, the controller 100 determines whether the soot flow compensation occurred after determining that the estimated total mass flow is above the engine exhaust mass flow associated with at least one of steps 706 or 714. In some other cases, the controller 100 determines whether the soot flow compensation occurred, for example, after the regeneration event was completed at step 810.

[0115] If the controller 100 determines that the flow split is balanced based on the soot load accumulation, 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 the correction factor based on the estimated soot load flow (e.g., mass flow relative to soot load).

[0116] At step 824, the controller 100 (e.g., correction circuit 109) calculates a correction factor based on the engine exhaust mass flow for each leg (e.g., half the engine exhaust mass flow) and a virtual value of the respective leg. In this case, the correction factor is a multiplier that, when applied to at least one of the estimated mass flows, increases or decreases the estimated mass flow to estimate the corrected mass flow. The following formula can be used to determine the correction factor: Correction factor = engine exhaust flow × 0.5 virtual value

[0117] For example, half of the engine exhaust mass flow represents the desired mass flow for each leg. The virtual value represents the mass flow estimated for the respective leg based on at least one of differential pressure or catalyst outlet pressure information. The controller 100 calculates the virtual value based on the estimated total mass flow and the flow split across the legs of the aftertreatment system 22. For example, if the engine exhaust mass flow is 50 kg / min, the controller 100 determines that each leg has a mass flow of 25 kg / min for a 50 / 50 flow split. If the estimated total mass flow is 55 kg / min with 30 kg / min for the first leg and 25 kg / min for the second leg, the controller 100 calculates the correction factor of 25 / 30 = 0.833 for the first leg and 25 / 25 = 1 for the second leg.In another example, if the first leg corresponds to a mass flow of 32 kg / min and the second leg corresponds to a mass flow of 23 kg / min, the controller 100 calculates the correction factors of 25 / 32 = 0.78 for the first leg and 25 / 23 = 1.08 for the second leg.

[0118] Based on the techniques described above, the controller 100 is configured to calculate or estimate a first virtual mass flow (e.g., first virtual value) of exhaust gas in the first branch 22A based on a first pressure differential value across the first DPF element in the first branch 22A. Further, the controller 100 is configured to estimate a second virtual mass flow (e.g., second virtual value) of exhaust gas in the second branch 22B based on a second pressure differential value across the second DPF element in the second branch 22B. Using the respective pressure differential values ​​for the respective branches, the controller 100 is configured to calculate the correction factor (e.g., via the formula provided above) based on the engine exhaust mass flow and at least one of the estimated first virtual mass flow or the estimated second virtual mass flow.

[0119] At step 826, the controller 100 (e.g., the correction circuit 109 and / or the modeling circuit 110) is configured to calculate the correction factor based on an adaptation model when the soot loading has not balanced the current. The process 800 proceeds to step 832 to perform an adaptation model-based correction factor calculation.

[0120] At step 832, the controller 100 (e.g., the modeling circuit 110) determines pressure differential values ​​(e.g., the first pressure differential value and the second pressure differential value) across respective particulate filters (e.g., the first DPF element and the second DPF element) over a time window. The time window includes various time intervals that represent the frequency for determining the pressure differential values. Examples of the time window and time intervals include, but are not limited to, a 1-minute time window with 1-second time intervals, a 5-minute time window with 5-second time intervals.

[0121] At step 834, the controller 100 (e.g., the modeling circuit 110) compares the pressure differential values ​​at each time interval to a set of calibrated tables. The set of calibrated tables includes a plurality of predetermined pressure differential values ​​representing various flow distributions of the engine exhaust mass flow. The predetermined pressure differential values ​​may be represented as a ratio of pressure differential values ​​between the branches, such as 50-50 for a balanced system, 55-45, 60-40, 65-45, 70-30, etc. Each calibrated table of the set of calibrated tables is assigned a corresponding pot for evaluating the comparison.

[0122] At step 836, the controller 100 (e.g., the modeling circuit 110) is configured, at each of the time intervals in the time window, to increment the score for at least one of the calibrated tables in the set in response to the calculated pressure difference values ​​(e.g., first and second pressure difference values) or the ratio of the pressure difference values ​​being comparable to or consistent with the predefined pressure difference values ​​or the predefined ratio of such a calibrated table. The controller 100 repeats this process for the remainder of the time window, and the process 800 proceeds to step 838.

[0123] At step 838, at the end of the time window, the controller 100 (e.g., correction circuit 109) calculates a correction factor for at least one of the trains of the aftertreatment system 22 based on a selected current split corresponding to a calibrated table with the highest score in the set. For example, based on the comparisons and at the end of the time window, the controller 100 collects the scores associated with each of the calibrated tables in the set.

[0124] By comparing the score of each calibrated table with each other, the controller 100 is configured to select the calibrated table with the highest score (e.g., pot). Further, the controller 100 selects the flow split corresponding to the calibrated table with the highest score and uses the selected flow split to calculate the correction factor. Similar to proportional correction, the controller 100 may apply the flow split to the engine exhaust mass flow to estimate the corrected mass flow for at least one of the legs (e.g., the high-flow leg and / or the low-flow leg). For example, in some arrangements, the controller 100 clears the scores or pots of the calibrated tables after selecting the calibrated table with the highest score, selecting the flow split, or calculating the correction factor.The adjustment model-based correction factor operations can be performed in conjunction with at least . Fig. 10 will be described in more detail.

[0125] As described herein, the controller 100 (e.g., the correction circuit 109) is configured to apply the correction factor to estimate a corrected mass flow. Then, the controller 100 (e.g., the adjustment circuit 111) is configured to adjust at least one of a reductant dosage, hydrocarbon dosage, or soot loading estimate based on the corrected first mass flow and the corrected second mass flow. For example, the controller 100 (e.g., the adjustment circuit 111) may decrease the reductant dosage for one of the legs with an overestimated mass flow (e.g., a decrease from the estimated mass flow to the corrected mass flow). In some cases, the controller 100 may increase the reductant dosage for one of the legs with an underestimated mass flow (e.g., an increase from the estimated mass flow to the corrected mass flow).

[0126] In various arrangements, 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. For example, an overestimated mass flow may result in an early or premature regeneration event (e.g., hydrocarbon dosing event). By applying the correction factor to the estimated mass flow, the overestimation is corrected, and the controller 100 may initiate the regeneration event based on the corrected mass flow for the respective train (e.g., relatively less frequently or at a later time compared to when the mass flow is overestimated). Similarly, after correcting an underestimated mass flow, the controller 100 may advance the timing or increase the frequency of the regeneration event for the associated train with the underestimated mass flow.

[0127] Further, the controller 100 (e.g., the adjustment circuit 111) corrects the soot loading estimate based on the corrected mass flow. For a leg with an overestimated mass flow, the controller 100 may decrease the soot loading estimate proportional to the decrease from the estimated mass flow to the corrected mass flow of the leg. For a leg with an underestimated mass flow, the controller 100 may increase the soot loading estimate proportional to the increase from the estimated mass flow to the corrected mass flow of the leg. Although examples herein include adjusting reductant dosing, hydrocarbon dosing, and soot loading estimation, the controller 100 is configured to adjust or control other components of the system 10 based on the corrected mass flow in at least one of the legs.

[0128] Fig. Figure 9 shows diagrams 902-912, which illustrate exemplary processes that can be performed with a delta pressure-based correction process of Fig. 8, such as for a newly installed system. Each diagram represents steps for performing a proportionality correction, such as in conjunction with at least steps 820, 828, and 830 of Fig. 8. Referring to graph 902, controller 100 (e.g., flow rate circuit 108) receives catalyst outlet pressure data from pressure sensor 16 in each of the legs, including the low-flow leg and the high-flow leg. As shown, the catalyst outlet pressure readings for both the low-flow leg (e.g., section 914) and the high-flow leg (e.g., labeled 65-35 in the legend) are above the data points representing a balanced flow split (e.g., labeled 50-50 in the legend).

[0129] At map 904, controller 100 estimates the mass flow for each leg based on the catalyst outlet pressure data from map 902. As shown, the exhaust mass flow for the second leg 22B (e.g., the low-flow leg, labeled "65-35 L2" in the legend) is overestimated when the catalyst outlet pressure data is used for mass flow estimation. Section 916 includes the estimated mass flow for the low-flow leg (e.g., the second leg 22B in this case), which is above the initial mass flow (e.g., 50-50 data points).

[0130] Next, at graph 906, the controller 100 estimates the total mass flow based on the first leg 22A and the second leg 22B (e.g., summing the respective mass flows). The controller 100 determines that the estimated total mass flow is greater than the engine exhaust mass flow, as shown in section 918. In this example, the engine exhaust mass flow is the initial data point, labeled, for example, as "50-50." Because the estimated total mass flow is greater than the engine exhaust mass flow, and with an indication that the system is newly installed, the controller 100 determines to perform a proportionality correction to correct the mass flow estimate for at least one of the legs (e.g., the low flow leg).

[0131] At chart 908, the controller 100 receives an indication that the catalyst element is clean (e.g., given that the system is newly installed). With respect to clean catalyst elements, the controller 100 is configured to determine which of the legs is the low current leg or the high current leg based on delta pressure information about the catalyst element (e.g., DPF delta pressure (dp)). For example, the controller 100 receives delta pressure information about the catalyst element of the respective leg. As shown, the controller 100 identifies the high current leg based on the catalyst delta pressure (e.g., labeled as "65-35") being above the output data points. Further, the controller 100 identifies the low current leg based on the catalyst delta pressure (e.g., in section 920) being below the output data points.Thus, the controller 100 is configured to use the delta pressure across the catalyst element to identify the low current leg and the high current leg.

[0132] The controller 100 calculates a ratio between the delta pressure of the high flow leg and the low flow leg. The ratio between the delta pressure can be used as part of the correction factor. For example, the controller 100 applies the ratio to the engine exhaust mass flow. In this case, the ratio is 65% for the high flow leg and 35% for the low flow leg, which are estimated based on the delta pressure of the respective catalyst element. The controller 100 calculates a first corrected mass flow for the low flow leg corresponding to 35% of the engine exhaust mass flow and a second corrected mass flow for the high flow leg corresponding to 65% of the engine exhaust mass flow. In some cases, the controller 100 applies the proportionality correction to the pressure data (e.g.,catalyst outlet pressure) from at least one of the strands so that the corrected pressure data can be used to calculate the corrected mass flow.

[0133] In various embodiments, the controller 100 is configured to ignore or skip estimating the corrected mass flow for the high-flow leg because, for example, the pressure data for the second leg 22B may not be affected by the restriction in the low-flow leg. For simplicity, the controller 100 is configured to correct the mass flow estimate for the low-flow leg without adjusting the estimated mass flow for the high-flow leg if the high-flow leg is not affected by the restriction. In other cases, the controller 100 is configured to adjust the estimated mass flows for both legs.

[0134] At chart 910, controller 100 applies the correction factor to the estimated mass flow of the low flow leg. In some cases, applying the correction factor may involve using the corrected mass flow calculated for the respective leg. As shown in section 922, controller 100 applies the correction factor to the low flow leg, thereby correcting / diagnoses the overestimation of the mass flow for the low flow leg. In some cases, controller 100 also applies a respective correction factor for the high flow leg to adjust the estimated mass flow of the second leg 22B. Compared to chart 904, the corrected mass flow of the low flow leg is below the output data points.

[0135] At plot 912, controller 100 aggregates or adds the corrected mass flow rates to determine a corrected total mass flow rate. As shown in section 924, compared to plot 906, the data points representing the corrected total mass flow rate are approximately the same as the engine exhaust mass flow rate data points. Therefore, the mass flows across the branches are representative of the engine exhaust mass flow rate entering aftertreatment system 22.

[0136] With reference to Fig. 10 is a block diagram of an exemplary adaptation model 1000 corresponding to at least step 826 of Fig. 8. The controller 100 (e.g., the correction circuit 109 and / or the modeling circuit 110) is configured to use the adjustment model 1000 to calculate a correction factor if at least the system is not newly installed and the current distribution is not balanced by the soot loading. The process for the adjustment model 1000 may be used in conjunction with steps 826 and 832-838 of Fig. 8. In various arrangements, the adaptation model 1000 may be executed continuously or periodically (e.g., at predefined time intervals or based on certain operating events of the engine 20, such as ignition of the engine, generation of the exhaust byproducts, etc.).

[0137] The adaptation model 1000 includes an input block 1002 and a flow split calculation block 1004. The input block 1002 includes processes for receiving and aggregating input data. The input data can be used in the flow split calculation block 1004, including processes for calculating the flow split of the mass flow between the strings. The calculated flow split can be monitored within a predefined time window (e.g., window-based monitoring logic), as described herein in step 1018.

[0138] At step 1006, the controller 100 receives or determines the (e.g., total) engine exhaust mass flow from the engine 20. The controller 100 calculates the engine exhaust mass flow based on a sum of the fresh air flow at the engine's inlet and the fuel flow delivered into the combustion chamber by at least one fuel injector. The fresh air flow corresponds to an intake air flow measured, for example, by a flow sensor or based on a sum of charge flow and EGR flow. The charge flow is calculated using the PV = mRT equation (e.g., ideal gas law). The EGR flow is calculated using the flow through the Venturi equation. In this case, there may be, for example, a charge pressure sensor and a Venturi pressure sensor in the engine architecture.The engine exhaust mass flow reflects the desired estimated total exhaust mass flow that is distributed between the aftertreatment system 22 branches.

[0139] At step 1008, the controller 100 applies a first-order filter to the calculated engine exhaust mass flow. 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 in response to applying the filter. The formula for a Kalman filter is provided as follows: y(k)=x(k)∗dt(tau+dt)+y(k−1)∗tau(tau+dt) y(k) = engine exhaust mass flow after applying the filter. k = incremental value as timestamp increments, like 1, 2, 3, 4, etc. dt = time difference, like 200 ms etc. tau = a predefined time value, such as 2 seconds, 3 seconds, 5 seconds, etc.

[0140] At step 1010, the controller 100 determines the volumetric flow in cubic meters per second (ACMS) for at least one branch (e.g., for comparison with the pressure information used to estimate the mass flow in the at least one branch). The ACMS may be calculated as follows: ACMS=m∗R∗TP m = mass flow. R = gas constant. T = temperature in Kelvin. P = gas pressure in KPa absolute, based on ambient pressure and / or external catalyst pressure.

[0141] At step 1012, the controller 100 retrieves or obtains various calibrated tables (e.g., sometimes referred to as models) from the memory 103 or the remote database (e.g., calibrated tables similar to those in Fig. 8). Individual calibrated tables include predefined pressure information (e.g., at least one of catalyst outlet pressure information or pressure difference information) corresponding to respective flow splits on the engine exhaust mass flow. Different pressure information corresponds to different flow splits. For example, a first calibrated table may correspond to a 60-40 flow split (e.g., 60% of the engine exhaust mass flow for a high flow leg and 40% of the engine exhaust mass flow for a low flow leg), a second calibrated table may correspond to a 65-35 flow split, a third calibrated table may correspond to a 70-30 flow split, etc. The calibrated tables may be generated or preconfigured based on the fuel reading data (e.g., injection data) that may be used to calculate the mass flow at the intake of the engine 20 and / or the exhaust of the engine 20.

[0142] In various arrangements, the controller 100 selects or maintains at least one set of calibrated tables based on the engine exhaust mass flow. For example, different engine exhaust mass flows result in different pressure measurements (e.g., catalyst outlet pressure data and pressure differential data) with respect to each branch of the aftertreatment system 22. Therefore, each set of calibrated tables may be configured for a respective engine exhaust mass flow. The controller 100 selects at least one of the set of calibrated tables based on comparisons between the calculated engine exhaust mass flow or ACMS, as described in connection with step 1010, with the predefined engine exhaust mass flow associated with, for example, the respective set of calibrated tables.

[0143] At step 1014, the controller 100 receives the sensed / measured catalyst outlet pressure information of at least one train (e.g., a first train 22A is used as an example) at a predetermined operating condition (e.g., fuel injection rate, reductant dosing rate, fresh air flow, torque request, etc.) of the engine 20 and / or the aftertreatment system 22.

[0144] At step 1016, the controller 100 applies the first-order filter to the measured catalyst outlet pressure of the first train 22A (or the second train 22B). The controller 100 uses the filtered catalyst outlet pressure information to compare with the predefined pressure information from the calibrated tables (e.g., in one of the sets of calibrated tables based on the engine exhaust mass flow). For example, the controller 100 compares the measured pressure value sampled by at least one of the pressure sensors 16 with the predefined pressure value of each calibrated table. The controller 100 may identify at least one calibrated table with the predefined pressure value closest to the measured pressure value.The controller 100 is configured to repeat processes of steps 1002 and 1004 at each interval within a predefined time window and to monitor the comparisons between the measured pressure values ​​and the predefined pressure values ​​at step 1018.

[0145] At step 1018, the controller 100 is configured to perform a window-based monitoring technique for monitoring the comparison of the measured pressure values ​​with modeled (e.g., predefined) pressure values ​​performed within the predefined time window. Within the time window, the controller 100 tracks the number of times a respective pair of measured pressure values ​​from the strands (e.g., pressure values ​​from the first and second strands 22A-B) matches the model pressure values ​​of at least one calibrated table. In response to each match, the controller 100 increments a score or pot corresponding to the calibrated table with the model pressure value. If the measured pressure value is between two model pressure values ​​of different calibrated tables, the controller 100 may increment the score of both calibrated tables.

[0146] At the end of the window, the controller 100 selects the model (e.g., calibrated table) with the highest score (e.g., highest number of matches). Selecting the calibrated table may correspond to selecting a flow split that corresponds to the calibrated table. The controller 100 is configured to use the selected flow split to calculate the correction factor and correct the estimated mass flow of at least one leg. As described above, the controller 100 may apply the correction factor to the estimated mass flow or calculate a corrected mass flow by applying the flow split to the engine exhaust mass flow to identify the mass flow traversing the high-flow leg and the low-flow leg.

[0147] With reference to Fig. 11, a diagram 1100 is shown illustrating a model-based approach corresponding at least to step 826 of Fig. 8 for an intake pipe restriction. The diagram 1100 represents example cases of measured pressure values ​​(e.g., catalyst outlet pressure) and estimated / calculated mass flows for the first branch 22A and the second branch 22B of the aftertreatment system 22. Case 1 corresponds to a balanced system with a 50-50 flow split. Case 2 corresponds to a 5743 flow split system with an intake pipe restriction (e.g., restriction upstream of the pressure sensor 16 used to measure pressure information). Case 3 corresponds to a 60-40 flow split system with an intake pipe restriction. As shown, the (e.g., pre-calibrated) lines in the diagram 1100 represent modeled pressure values ​​relative to modeled mass flows for certain calibrated tables. 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 current split. Line 50 represents a calibrated table with a 50-50 current split or output values.

[0148] In case 2, the controller 100 determines that the data points of the first leg 22A and the second leg 22B are aligned with the data points of the calibrated table corresponding to the 57-43 flow split. Accordingly, the controller 100 may select the 57-43 flow split to calculate the 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 leg (e.g., the second leg 22B in this case). Correcting the mass flow may be performed in conjunction with Fig. 7. When correcting the estimated mass flow, the controller 100 determines that the data points of the first leg 22A and the second leg 22B are aligned with the data points of the calibrated table corresponding to the 40-60 outlet flow split table. In some cases, the controller 100 determines that the data points corresponding to the first leg 22A are aligned with the 60-40 inlet flow split table and selects the flow split without correcting the data points of the second leg 22B. Accordingly, the controller 100 may select the 60-40 flow split, for example, to calculate the correction factor.

[0149] With reference to Fig. Figure 12 shows a graph 1200 illustrating a model-based approach for a tailpipe restriction. Similar to graph 1200, 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 for 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 precalibrated lines for the tailpipe restriction differ from the lines for the inlet pipe restriction because the location of the restriction affects the pressure readings and the mass flow estimation. In case 2, the controller 100 determines that the data points of the first string 22A are aligned with the calibrated table corresponding to a 57-43 current split (e.g.,a comparison between the measured values ​​and the modeled values). The controller 100 selects the 57-43 current split to calculate the correction factor. In Case 3, the controller 100 compares the measured data points with the modeled data points and identifies an alignment with the calibrated table that corresponds to a 60-40 current split. Accordingly, the controller 100 selects the 60-40 current split to calculate the correction factor. The controller 100 may interpolate between other tables or models based on other measured values ​​from the pressure sensors 16.

[0150] Fig. Figure 13 shows exemplary diagrams 1302 -1308 showing monitored data for a model-based approach of Fig. 8, where 50-50 current distribution data is adapted to a respective current distribution table. The diagram 1302 represents, among other diagrams of Fig. 14- Fig. 16, such as diagrams 1402, 1502 and 1602, represent the predicted power split between the trains of the aftertreatment system 22. As shown, the controller 100 is capable of calculating the 50-50 power split data using the model-based approach of Fig. 8 to a 50-50 current sharing table. Index 1 of diagram 1302 represents or corresponds to the 50-50 current sharing table.

[0151] Fig. Figure 14 shows exemplary diagrams 1402 -1408 showing monitored data for a model-based approach of Fig. 8, where 40-60 stream split data are compared with a respective stream split table. As shown, the controller 100 is capable of comparing the 40-60 stream split data using the model-based approach of Fig. 8 with a 40-60 flow split table. Index 5 of chart 1402 represents or corresponds to the 40-60 intake flow split table. In chart 1404, updates from time 500 to approximately time 2250 may be interrupted because the minimum threshold for temperature or exhaust mass flow is not met.

[0152] Fig. Figure 15 shows example diagrams 1502 -1508 showing monitored data for a model-based approach of Fig. 8, wherein 60-40 power split data is compared with at least one respective power split table. As shown, the controller 100 is capable of comparing the 60-40 power split data using the model-based approach of Fig. 8 to match at least one of the 55-45 or 60-40 flow split tables. Index 6 of diagram 1502 represents or corresponds to the 55-45 outlet flow split table, and index 8 of diagram 1502 represents or corresponds to the 60-40 outlet flow split table.

[0153] Fig. Figure 16 shows exemplary diagrams 1602 -1608 showing monitored data for a model-based approach of Fig. 8, wherein TC-NRTC 50-50 current split data (e.g., exemplary replica data or test data) are compared with respective current split tables. As shown, the controller 100 is capable of comparing the TC-NRTC 50-50 current split data using the model-based approach of Fig. 8 with the 50-50 current sharing table. Index 5 of diagram 1602 represents or corresponds to the 50-50 current sharing table. While Fig. 13 represents a stationary cycle (e.g. diagram 1306), Fig. 16 represents a transition cycle (e.g. diagram 1606).

[0154] With reference to Fig. 17 is an overview process flow diagram for another example process 1700 for managing mass flow splitting in a multi-lane aftertreatment system of the engine system of Fig. 1 using NO x -Measurements are shown. The processes, operations or steps of Fig. 17 may be performed by the components (e.g., controller 100, I / O device 120, aftertreatment system 22, sensors, etc.) of system 10, data processing system, cloud computing environment, or any other computing devices described herein in connection with the Fig. 1-16. 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 the remote device for processing, or vice versa.

[0155] At step 1702, the controller calculates (e.g., the NO x -circuit 107) a first NO x -Conversion efficiency of the first train 22A. The controller 100 calculates the first NO x -Conversion efficiency based on a difference between the amount / level of NO xat the inlet of the first strand 22A or upstream of a first catalyst element (e.g. first SCR catalyst element) and the amount of NO x at the outlet of the first strand 22A or downstream of the first catalyst element.

[0156] At step 1704, the controller calculates (e.g., the NO x -circuit 107) a second NO x -Conversion efficiency of the second train 22B. The controller 100 calculates the second NO x -Conversion efficiency based on a difference between the amount of NO x at the inlet of the second strand 22B or upstream of a second catalyst element (e.g. second SCR catalyst element) and the amount of NO x at the outlet of the second strand 22B or downstream of the second catalyst element.

[0157] At step 1706, the controller calculates (e.g., the NO x -circuit 107) an average / mean NO x-Conversion efficiency based on the first NO x -Conversion efficiency and the second NO x -Conversion efficiency (e.g. average between the two NO x conversion efficiencies). At step 1708, the controller (e.g., the NO x -Circuit 107) configured to calculate a difference between the first NO x -Conversion efficiency and the second NO x -Conversion efficiency. The controller 100 is configured to calculate the average NO x -Conversion efficiency and the difference following determining that the ammonia-to-NO x -Ratio (ANR) between the first strand 22A and the second strand 22B is similar. A similar ANR indicates that the strands have a similar NO x conversion efficiency. So if the average NO x conversion efficiency is below a threshold or if the difference between the first NOx -Conversion efficiency and the second NO x -Conversion efficiency is greater than a threshold, this indicates that there is a restriction in the tailpipe.

[0158] At step 1710, the controller (e.g., correction circuit 109) is responsive to determining that the average NO x conversion efficiency is less than a first threshold or the difference between the first NOx conversion efficiency and the second NO x conversion efficiency is greater than the first threshold, configured to calculate an adjustment factor to balance an estimated first mass flow and an estimated second mass flow. The adjustment factor may be based on the ANR of the low NO x conversion efficiency can be calculated. For example, if the ANR of the low NO xconversion efficiency is greater than (or equal to) a threshold value, this indicates that there is ammonia slip from the low NO strand. x conversion efficiency. Otherwise, if the ANR of the strand with low NO x conversion efficiency is less than the threshold, this indicates that there is a NO x -Slippage from the strand with low NO x conversion efficiency. The adjustment factor can be predefined based on whether there is an ammonia slip or NO x -slippage.

[0159] At step 1712, the controller (e.g., flow circuit 108 or correction circuit 109) is configured to estimate an adjusted first mass flow of the exhaust gas in the first branch 22A and an adjusted second mass flow of the exhaust gas in the second branch 22B using the adjustment factor. If there is an indication of ammonia slip, the controller 100 estimates the adjusted mass flow by decreasing the estimated mass flow. If there is an indication of NO x slip, the controller 100 estimates the adjusted mass flow by increasing the estimated mass flow.

[0160] At step 1714, the controller (e.g., adjustment circuit 111) is configured to adjust at least one of a reductant dosage, a hydrocarbon dosage, or a soot loading estimate based on the adjusted first mass flow and the adjusted second mass flow. In various embodiments, the acts, techniques, or features of process 1700 may be used in conjunction with Fig. 18 will be described in more detail.

[0161] With reference to Fig. 18 is a process flow diagram of an exemplary process 1800 for managing mass flow splitting in a multi-train aftertreatment system configured with Fig. 17, as described in more detail. The processes, operations or steps of Fig. 18 may be performed by the components (e.g., controller 100, I / O device 120, aftertreatment system 22, sensors, etc.) of system 10, data processing system, cloud computing environment, or any other computing devices described herein in connection with the Fig. 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 the remote device for processing, or vice versa.

[0162] The process 1800 begins at step 1802. The process 1800 may be performed before or after determining that the power distribution is unbalanced. The process 1800 may be performed in addition to or alternatively to the process 800 of Fig. 8. At step 1802, the controller 100 is configured to initiate a cleaning operation for the catalyst element (e.g., the DPF element 40, the SCR catalyst element 50, etc.). After the catalyst element(s) have been cleaned (e.g., removing the soot loading or deposit accumulation factors related to an imbalanced system), the controller 100 proceeds to step 1804.

[0163] At step 1804, the controller 100 determines whether the average ammonia to NO x-Ratio (ANR) between the strands is similar. The ANR can be measured in molar, where 1.1 molar indicates that there is, for example, 1.1 times the amount of ammonia (e.g., reducing agent) compared to NO x An ANR of approximately 1 (e.g. between 0.9-1.1, 0.95-1.05, 0.98-1.02, etc.) represents a desired ratio of reducing agent to NO x ready so that the amount of reducing agent and NO x at the tailpipe is below a desired level (e.g., in the case where the mass flow estimate is accurate). If the ANR is similar between the legs, process 1800 proceeds to step 1806. Otherwise, process 1800 remains at step 1804, and controller 100 determines whether the ANR is similar between the legs at another time interval.

[0164] In various embodiments, in a system without tailpipe restriction, a similar ANR between the strands results in an average conversion efficiency (e.g., NO x-conversion efficiency between the strands) that is greater than or equal to a conversion efficiency threshold. Further, in the system without tailpipe restriction, a similar ANR between the strands results in a difference between the conversion efficiencies of the first and second strands 22A-B that is less than or equal to another threshold. However, as discussed herein, if the ANR between the strands is similar and at least one of the average conversion efficiency or the difference between the conversion efficiencies is above the desired level (e.g., in step 1808), the controller 100 is configured to determine that there is a tailpipe restriction causing an inaccurate estimation of mass flow rates. The inaccurate estimation of mass flow results in an erroneous dosing rate of reductant. The erroneous dosing rate results in at least one of NO x-Slip or reducing agent slip (e.g. ammonia slip). The NO x - or reducing agent slip corresponds to an amount of NO x or reductant at the tailpipe that is above a desired level. Therefore, as discussed herein, the conversion efficiency of the strands can be used to determine if there is a restriction in the tailpipe and calculate an adjustment factor to correct / adjust the estimated mass flow and / or reductant dosing rate.

[0165] In some cases, the system 10 may be implemented or configured with ammonia sensors (not shown). The ammonia sensors may be positioned downstream of the catalyst element (e.g., DPF element 40, SCR catalyst element 50, etc.) of the respective strands. The ammonia sensors may be positioned at the tailpipe of the respective strands. In this case, with a similar ANR between the strands, the controller 100 is configured to detect the difference in the level of ammonia and / or NO x (e.g. using the ammonia sensor or NO x -sensor 12) between each branch. If the difference between the branches is greater than or above a threshold, the controller 100 determines that there is a restriction in the tailpipe in at least one of the branches, resulting in the erroneous mass flow estimate. Similar to using the NO xconversion efficiency, the controller 100 may adjust the adjustment factor using the level of reductant or NO x -Calculate slip, for example, to correct the estimated mass flow or dosing rate.

[0166] At step 1806, the controller 100 (e.g., the NO x -Circuit 107) configured to calculate / calculate the mean or average NO x Conversion efficiency (CE) between the first train 22A and the second train 22B. To calculate the average, the controller 100 is configured to calculate a first NO x -Conversion efficiency of the first strand 22A and a second NO x -Conversion efficiency of the second strand 22B. The NO x -Conversion efficiency of each strand is determined based on the difference between the amount of NO x at the inlet of the strand and the amount of NO xat the outlet of the branch. The controller 100 calculates the average NO x -Conversion efficiency based on the first and second NO x -Conversion efficiencies. Furthermore, the controller 100 is configured to calculate a difference in NO x -Conversion efficiencies between strands.

[0167] In step 1808, the controller 100 determines (e.g., the NO x circuit 107), whether the average conversion efficiency is less than a threshold (e.g., a first threshold) or the difference between the NO x conversion efficiencies is greater than the threshold. For example, the threshold for the average conversion efficiency can be 80%, 85%, 90%, etc. The threshold for the difference between NO xConversion efficiency can 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.

[0168] At step 1810, the controller 100 receives a sample estimated mass flow of each leg for corrective adjustment (e.g., to be corrected / adjusted using an adjustment factor). The controller 100 (e.g., the flow circuit 108) may estimate the mass flow of each leg based on pressure information (e.g., catalyst outlet pressure or pressure differential). In some cases, the controller 100 receives the estimated mass flow from a remote computing system that has processed the pressure data or other data related to the mass flow.

[0169] In various arrangements, the controller 100 (e.g. the NO x -Circuit 107) configured to calculate the first NOx -Conversion efficiency of the first strand 22A with the calculated second NO x conversion efficiency of the second train 22B. Based on the comparison, the controller 100 determines which of the trains has a lower NO x conversion efficiency. The strand with the lower NO x -Conversion efficiency can be defined as a strand with low conversion efficiency (e.g. a strand with low NO x -conversion efficiency). Furthermore, the controller 100 determines the ANR of the low conversion efficiency strand.

[0170] At step 1812, the controller 100 (e.g., the NO xCircuit 107) compares the ANR of the low conversion efficiency train with a predetermined threshold (e.g., a second threshold). This threshold may be predefined by the administrator of system 10 or configured via operator I / O device 120. The threshold may be predefined as 1 molar, 1.1 molar, 0.9 molar, among others. For example, an ANR of less than 0.9 for the low conversion efficiency train (e.g., less than 80% conversion efficiency) may result in a NO x -slip at the tailpipe. In another example, an ANR of 1.3 for the low conversion efficiency leg (e.g., less than 85%-90% conversion efficiency) may indicate NH3 slip at the tailpipe. Comparing the ANR of the low conversion efficiency leg with the threshold represents whether a NO x-Slip or ammonia slip has occurred. For example, if the ANR of the low conversion efficiency train is greater than (or in some cases equal to) the threshold, the controller 100 determines that there is ammonia slip from the low conversion efficiency train because the ratio of ammonia is higher than the ratio of NO x in the ANR. In this case, the process 1800 proceeds to step 1814. Conversely, if the ANR is less than the threshold, the controller 100 determines that there is a NO x -Slippage from the strand with low conversion efficiency because the ratio of ammonia is lower than the ratio of NO x in the ANR. In response to identifying or determining that there is a NO x -Slippage from the strand with low conversion efficiency, the process 1800 proceeds to step 1816.

[0171] At step 1814, the controller 100 (e.g., the adjustment circuit 111) is configured to adjust the dosing rate of the reductant based on the ammonia slip from the low conversion efficiency leg. For example, the controller 100 may decrease the dosing rate due to the ammonia slip (e.g., caused by overdosing of the reductant). In this case, the overdosing of the reductant is due to an overestimation of the mass flow. The controller 100 may use a predetermined adjustment factor to decrease the estimated mass flow of the low conversion efficiency leg (e.g., referred to as an adjusted mass flow). For example, a correction factor (e.g., correction multiplication factor) of 1.1 may be initially used to increase the mass flow, or a correction factor of 0.9 may be initially used to decrease the mass flow.In response to the adjustment, the controller 100 decreases the dosing rate of the reductant proportional to the decrease in the estimated mass flow. 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 may be configured by the 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 dosing rate or the estimated mass flow of the other leg that differs from the leg with low conversion efficiency cannot be adjusted because the erroneous estimate relates to the leg with low conversion efficiency.

[0172] At step 1816, in response to determining that the ANR of the low conversion efficiency leg is below the threshold, the controller 100 is configured to adjust the dosing rate of the reductant by increasing the dosing rate. A low ANR (e.g., ANR below the threshold) for the low conversion efficiency leg indicates that there is a NO x -Slip in the train with low conversion efficiency. Therefore, the controller 100 is configured to increase the dosing rate by a predetermined amount in response to the NO x -increase slippage.

[0173] The NO x Slippage may be a result of an underestimated mass flow. In this case, the controller 100 is responsive to determining that the average conversion efficiency is less than the threshold (e.g., first threshold) or the difference between the conversion efficiencies of the trains (e.g., first and second NOx -conversion efficiencies) is greater than the threshold, configured to calculate an adjustment factor to compensate for at least one of the estimated first mass flow for the first train 22A or an estimated second mass flow for the second train 22B. The adjustment factor may be predetermined by the administrator, such as to reduce the estimated mass flow in the case of ammonia slip and to reduce the estimated mass flow in the case of NO x -slip. In this case, the controller 100 applies the adjustment factor to the estimated mass flow of the low conversion efficiency train to adjust the reductant dosing rate based on NO x -Slip. In response to the adjustment, the controller 100 is configured to increase the reductant dosing rate based on the increased (e.g., adjusted) mass flow.

[0174] At step 1818, the controller 100 (e.g., the NOx -Circuit 107) is configured to determine whether the low conversion efficiency leg improves following the application of the adjustment factor or the adjustment of the reductant dosing rate. To determine whether the low conversion efficiency leg improves, the controller 100 calculates a third NO x -Conversion efficiency of the low NO strand x Conversion efficiency following adjustment of the reducing agent dosing rate. The controller 100 compares the third NO xConversion efficiency with a threshold (e.g., the third threshold), which may be similar to the threshold described in steps 1608 or 1612. If the third conversion efficiency is less than the threshold, the low conversion efficiency strand does not improve, and process 1800 proceeds to step 1822. If the third conversion efficiency is greater than or equal to the threshold, the low conversion efficiency strand improves, and process 1800 proceeds to step 1820.

[0175] In various arrangements, to determine whether the low conversion efficiency strand is improving, the controller 100 compares the ANR (e.g., the new ANR) of the low conversion efficiency strand after adjusting the dosing rate to the threshold (e.g., the third threshold). The threshold may be based on the ANR of the low conversion efficiency strand before the adjustment, such as a predefined percentage or amount of improvement over the previous ANR. The threshold may be a conversion efficiency threshold. In some cases, the controller 100 compares the new ANR to the previous ANR to determine whether to maintain the correction factor. The controller 100 may apply one or more subsequent correction factors until the previous value(s) increases to the desired threshold.

[0176] At step 1820, the controller 100 is configured to reset a value relating to the number of iterations at which the dosing rate readjustment was performed (e.g., incremented in step 1822). The process 1800 proceeds to step 1832 after resetting this value.

[0177] At step 1822, the controller 100 determines that the low conversion efficiency strand is not improving due to an incorrect adjustment (e.g., direction or magnitude of adjustment). The controller 100 increments a value representing the number of iterations in which the dosing rate was adjusted (e.g., in this case, the value = 1 after the increment).

[0178] At step 1824, the controller 100 determines whether the dosing rate of the reducing agent 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, for example, to step 1828.

[0179] At step 1826, the controller 100 readjusts the dosing rate of the reducing agent in response to determining that the low conversion efficiency leg has not improved following 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 is configured to readjust the dosing by reducing the initial adjustment amount. For example, if the dosing rate was increased (e.g., in step 1816), the controller 100 is configured to decrease the adjusted dosing rate proportional to the increased amount (e.g., half, third, quarter, etc., of the increased amount). In some cases, the controller 100 reapplies the initial adjustment factor or replaces it with a different adjustment factor to adjust the estimated mass flow.The second adjustment factor can 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).

[0180] In another example, if the dosing rate has been decreased (e.g., in step 1814), the controller 100 is configured to increase the adjusted dosing rate proportional to the decreased amount (e.g., half, third, quarter, etc., of the decreased amount). In some cases, the controller 100 reapplies the initial adjustment factor or replaces it with a different adjustment factor to adjust the estimated mass flow. The second adjustment factor may be smaller than the initial adjustment factor, so the correction step is reduced (e.g., the dosing rate is decreased by a smaller amount).

[0181] Referring again to step 1818, the controller 100 determines whether the low conversion efficiency leg has improved after readjusting the reductant dosing rate (e.g., reducing the correction step). To make this determination, the controller 100 calculates a fourth NO x -Conversion efficiency of the strand with low conversion efficiency and compares the fourth NO x -Conversion efficiency with a different threshold (e.g., fourth threshold). The threshold may be similar to or different from the third threshold. In some cases, the controller 100 determines the ANR of the low conversion efficiency train after readjustment. If the low conversion efficiency train has improved (e.g., improvement in NO xConversion efficiency or ANR), the process 1800 proceeds to step 1820. If the low conversion efficiency strand has still not improved, the process 1800 proceeds to step 1822, and the value is incremented. Since the value is greater than 1, the process proceeds to step 1828 at this step.

[0182] At step 1828, the controller 100 resets the correction adjustment (e.g., the dosing rate adjustment) and the value relating to the number of adjustments made to the dosing rate.

[0183] At step 1830, the controller 100 triggers a fault and proceeds to step 1832. The controller 100 triggers the fault in response to determining that the fourth NO xConversion efficiency is less than the fourth threshold. Triggering the fault may involve the controller 100 transmitting a signal or message to the operator I / O device 120 indicating that there is a limitation or imbalance in the aftertreatment system 22 and that a service center visit is necessary. In some cases, the signal or message may be transmitted to a service center device for diagnosis or scheduling a service appointment. In certain cases, the triggered fault may be a service light on the instrument panel of the vehicle incorporating the system 10.

[0184] At step 1832, the controller 100 is configured to pause or stop the operations in process 1800 and restart the process by proceeding to step 1804. In some cases, if the imbalance is diagnosed or resolved after another iteration of the process 1800 (e.g., the balanced mass flow is corrected), the controller 100 may reset the triggered fault. In various embodiments, the controller 100 is configured to further adjust the at least one of the hydrocarbon dosage or the soot loading estimate based on the adjusted mass flow of at least one of the trains by adjusting or correcting the estimated mass flow.

[0185] In various embodiments, in response to addressing the ANR and / or conversion efficiency of the low conversion efficiency leg, the low conversion efficiency leg becomes the high (or normal) conversion efficiency leg, and the other leg may be the low conversion efficiency leg. Process 1800 may be repeated for the other leg (e.g., correcting the estimated mass flow of the other leg).

[0186] With reference to Fig. 19 are diagrams of an exemplary process 1900 for NO x -monitoring-based correction, the Fig.18. Plot 1902 shows increases in engine exhaust mass flow at various time intervals. Plot 1904 shows increases in the bed temperature of a catalyst element (e.g., SCR catalyst element 50) corresponding to the increased engine exhaust mass flow at various time intervals. The sudden increase in temperature may cause ammonia slip at the tailpipe of the respective train. The sudden increase in engine exhaust mass flow and catalyst temperature may be due to a mass flow estimation error with tailpipe limitation.

[0187] As shown in graph 1906, the conversion efficiencies (e.g., of the SCR catalyst element 50) between the two strands and the ANR can be used as the conditions indicating a non-equilibrium system. For example, in a time frame between 4.26 hours and 4.29 hours, the conversion efficiencies of the two strands (e.g., the average conversion efficiency) are below a predetermined threshold (e.g., below 95%, 90%, etc.) or the difference between the conversion efficiencies is greater than or equal to a threshold (e.g., greater than 3%, 5%, etc.). Furthermore, in the same time frame, the ANR between the first and second strands 22A-B is similar (e.g., about 1-1.25). Satisfying the conditions indicates that the mass flow estimate with the tailpipe restriction is faulty.

[0188] Diagram 1908 shows the NO xmeasurements (e.g., in parts per million (ppm)) and Chart 1910 shows the reductant dosage (e.g., estimated by controller 100 or measured by an ammonia sensor) during the same time frame as Chart 1906. As shown, given the NO x levels, the second strand 22B an excess amount of reducing agent compared to the NO x -level that traverses the system.

[0189] Chart 1912 shows the mass flow estimated during the same time window as charts 1906-1910. As shown, the estimated mass flow for both the first and second train 22B increased from 9 kg / min to 20-22 kg / min at approximately 4.24-4.25 hours. In this case, the estimated mass flow for at least one of the trains is inaccurate due to the tailpipe limitation. Therefore, the controller 100 is configured to perform the operations described in process 1800 to correct the estimated mass flow and adjust the reductant dosing rate to reduce NO x - and reductant slip. In this case, the second leg 22B is the low-flow leg but is estimated as the high-flow leg, while the first leg 22A is the high-flow leg but is estimated as the low-flow leg relative to the second leg 22B.

[0190] The diagram 1914 shows the adjusted estimated mass flows after applying an adjustment / correction factor to the first leg 22A and / or the second leg 22B. For example, there is reductant slip from the second leg 22B due to the overestimated mass flow and ammonia slip in the first leg 22A due to the underestimated mass flow. In this case, the correction factor applied to the legs includes decreasing the estimated mass flow for the second leg 22B and increasing the estimated mass flow for the first leg 22A by a predetermined amount proportional to the overestimation or underestimation of the estimated mass flow. The amount of overestimation or underestimation may be at the level of NO x -Slip or reductant slip.

[0191] Diagram 1916 shows the reducing agent dosing rate and diagram 1918 shows the measured NO xLevel in the same time window as chart 1914 after the adjustment. As shown, the reductant dosage amount was improved after applying the adjustment / correction factor. Based on the improved results from the correction, a further correction can be initiated (e.g., increasing the adjustment factor) or the correction can be maintained. Accordingly, as shown in chart 1920, the conversion efficiency for the first train 22A and the second train 22B is improved after applying the adjustment factor. III. Construction of exemplary embodiments

[0192] 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 specific to particular embodiments. Certain features described in this specification in connection with separate embodiments may also be implemented in combination in a single implementation. Conversely, various features described in connection with a single implementation may also be implemented in multiple embodiments separately or in any suitable subcombination.Furthermore, although features may be described as operating in certain combinations and may even be initially claimed as such, in some cases one or more features from a claimed combination may be dropped from the combination, and the claimed combination may be directed to a sub-combination or variation of a sub-combination.

[0193] As used herein, the terms "substantially," "generally," "approximately," and similar terms are intended to have a broad meaning consistent with common and accepted usage by one of ordinary skill in the art to which the subject matter of this disclosure relates. Those skilled in the art upon review of this disclosure should understand that these terms are intended to enable description of particular described and claimed features without limiting the scope of those features to the precise numerical ranges provided. Accordingly, these terms should be construed to indicate that insignificant or insignificant modifications or alterations of the described and claimed subject matter are considered to be within the scope of the invention as set forth in the appended claims.

[0194] The terms "coupled" and the like, as used herein, mean the direct or indirect connection of two components to one another. Such connection may be stationary (e.g., permanent) or movable (e.g., removable or detachable). Such connection may be achieved by integrally forming the two components, or the two components and any additional intermediate components, as a single unitary body, with the two components, or the two components and any additional intermediate components, being secured to one another.

[0195] The terms "fluidically coupled to" and the like, as used herein, mean that the two components or objects have a path formed between the two components or objects in which a fluid, such as air, exhaust gas, liquid reductant, gaseous reductant, aqueous reductant, gaseous ammonia, etc., can flow, either with or without intervening components or objects. Examples of fluid couplings or configurations for enabling fluid communication may include tubes, channels, or any other suitable components for enabling the flow of a fluid from one component or object to another.

[0196] It is important to note that the construction and arrangement of the system shown in the various example embodiments is only illustrative and not restrictive. It is desired that all changes and modifications that fall within the spirit and / or scope of the described embodiments be protected. It is understood that some features may not be necessary, and embodiments lacking the various features may be considered within the scope of the application, which scope is defined by the following claims. When the language "a portion" is used, the subject matter may include a portion and / or all of the subject matter, unless expressly stated otherwise.

[0197] Additionally, the term "or" is used in its inclusive sense (rather than its exclusive sense), so that, for example, when used to join a list of items, the term "or" means one, some, or all of the items in the list. Conjunctive language such as the phrase "at least one of X, Y, and Z," unless explicitly stated otherwise, is to be understood differently with context, as 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). Thus, such conjunctive language is generally not intended to imply that particular embodiments require at least one of X, at least one of Y, and at least one of Z to be present unless otherwise stated.

[0198] Additionally, the use of value ranges (e.g., W to P, etc.) herein includes their maximum and minimum values ​​(e.g., W to P includes W and includes P, etc.), unless otherwise specified. Furthermore, a value range (e.g., W to P, etc.) does not necessarily require the inclusion of intermediate values ​​within the value range (e.g., W to P can only include W and P, etc.), unless otherwise specified.

Claims

[1] Aftertreatment system comprising: a first strand comprising one or more first post-treatment components; a second strand comprising one or more second post-treatment components; and a controller configured to: Estimating a first mass flow of exhaust gas in the first branch; Estimating a second mass flow of the exhaust gas in the second branch; Calculating an estimated total mass flow based on the estimated first mass flow and the estimated second mass flow; in response to determining that the estimated total mass flow is greater than an engine exhaust mass flow, calculating a correction factor to balance the estimated first mass flow and the estimated second mass flow; Estimating a corrected first mass flow of the exhaust gas in the first branch and a corrected second mass flow of the exhaust gas in the second branch using the correction factor; and Adjusting at least one of a reductant dosage, hydrocarbon dosage, or soot loading estimation based on the corrected first mass flow and the corrected second mass flow. [2] The aftertreatment system of claim 1, wherein the controller is further configured to: 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 calculating the correction factor. [3] The aftertreatment system of claim 2, wherein, following regenerating the at least one of the first SCR catalyst or the second SCR catalyst and prior to calculating the correction factor, the controller is further configured to: Estimating a third mass flow of the exhaust gas in the first branch; Estimating a fourth mass flow of the exhaust gas in the second branch; and Calculate a second estimated total mass flow based on the third mass flow and the fourth mass flow. [4] The aftertreatment system of claim 1, wherein the controller, in response to determining that the estimated total mass flow is greater than the engine exhaust mass flow, is further configured to: Determine whether the first string or the second string is newly installed; and Calculating the correction factor in response to determining that the first string or the second string is newly installed. [5] The aftertreatment system of claim 1, wherein the controller is configured to calculate the correction factor: Determining a ratio between a first pressure difference value across a first particulate filter of the one or more first aftertreatment components and a second pressure difference value across a second particulate filter of the one or more second aftertreatment components; and Calculate the correction factor based on the ratio between the first pressure difference value and the second pressure difference value. [6] The aftertreatment system of claim 1, wherein the controller, in response to determining that the estimated total mass flow is greater than the engine exhaust mass flow, is further configured to: Determine whether the first string or the second string is newly installed; Estimating a soot loading flow in response to determining that neither the first train nor the second train is newly installed; and Calculate the correction factor based on the estimated soot loading flow. [7] The aftertreatment system of claim 1, wherein the controller is further configured to: Estimating a first virtual mass flow of the exhaust gas in the first branch based on a first pressure difference value across a first particulate filter of the one or more first aftertreatment components; Estimating a second virtual mass flow of the exhaust gas in the second branch based on a second pressure difference value across a second particulate filter of the one or more second aftertreatment components; and Calculating the correction factor based on the engine exhaust mass flow and at least one of the estimated first virtual mass flow or the estimated second virtual mass flow. [8] The aftertreatment system of claim 1, wherein the controller is further configured to: Determining a first pressure difference value across a first particulate filter of the one or more first aftertreatment components and a second pressure difference value across a second particulate filter of the one or more second aftertreatment components over a time window comprising a plurality of time intervals; and Comparing, in each of the plurality of time intervals, the first pressure difference value and the second pressure difference value with a set of calibrated tables comprising a plurality of predetermined pressure difference values ​​for different flow divisions of the engine exhaust mass flow; and Calculating the correction factor based on the comparison between the first pressure difference value and the second pressure difference value with the set of calibrated tables at one end of the time window. [9] The aftertreatment system of claim 8, wherein the controller is further configured to calculate the correction factor: in each of the plurality of time intervals of the time window, incrementing a score for one of the set of calibrated tables in response to the first pressure difference value and the second pressure difference value matching the one of the set of calibrated tables; and Select, at the end of the time window, a current split corresponding to the set of calibrated tables with a highest score to calculate the correction factor. [10] A method comprising: Estimating, by a controller, a first mass flow of exhaust gas in a first train comprising one or more first aftertreatment components; Estimating, by the controller, a second mass flow of the exhaust gas in a second train comprising one or more second aftertreatment components; Calculating, by the controller, an estimated total mass flow based on the estimated first mass flow and the estimated second mass flow; in response to determining that the estimated total mass flow is greater than an engine exhaust mass flow, calculating, by the controller, a correction factor to balance the estimated first mass flow and the estimated second mass flow; Estimating, by the controller, a corrected first mass flow of the exhaust gas in the first branch and a corrected second mass flow of the exhaust gas in the second branch using the correction factor; and Adjusting, by the controller, at least one of a reductant dosing, hydrocarbon dosing, or soot loading estimation based on the corrected first mass flow and the corrected second mass flow. [11] The method of claim 10, further comprising: 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 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. [12] The method of claim 11, wherein the method further comprises, following regenerating the at least one of the first SCR catalyst or the second SCR catalyst and prior to calculating the correction factor: Estimating, by the controller, a third mass flow of the exhaust gas in the first line; Estimating, by the controller, a fourth mass flow of the exhaust gas in the second branch; and Calculating, by the controller, a second estimated total mass flow based on the third mass flow and the fourth mass flow. [13] The method of claim 10, wherein the method comprises, in response to determining that the estimated total mass flow is greater than the engine exhaust mass flow: Determining, by the controller, whether the first string or the second string is newly installed; and Calculating, by the controller, the correction factor in response to determining that the first string or the second string is newly installed. [14] The method of claim 10, wherein calculating the correction factor comprises: Determining, by the controller, a ratio between a first pressure difference value across a first particulate filter of the one or more first aftertreatment components and a second pressure difference 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 difference value and the second pressure difference value. [15] The method of claim 10, wherein the method comprises, in response to determining that the estimated total mass flow is greater than the engine exhaust mass flow: Determine, by the controller, whether the first string or the second string is newly installed; Estimating, by the controller, a soot loading flow in response to determining that neither the first train nor the second train is newly installed; and Calculate, by the controller, the correction factor based on the estimated soot loading flow. [16] The method of claim 10, further comprising: estimating, by the controller, a first virtual mass flow of the exhaust gas in the first train based on a first pressure difference value across a first particulate filter of the one or more first aftertreatment components; Estimating, by the controller, a second virtual mass flow of the exhaust gas in the second branch based on a second pressure difference 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 engine exhaust mass flow and at least one of the estimated first virtual mass flow or the estimated second virtual mass flow. [17] The method of claim 10, further comprising: Determining, by the controller, a first pressure difference value across a first particulate filter of the one or more first aftertreatment components and a second pressure difference 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, in each of the plurality of time intervals, the first pressure difference value and the second pressure difference value with a set of calibrated tables comprising a plurality of predetermined pressure difference values ​​for different flow divisions of the engine exhaust mass flow; and Calculating, by the controller, the correction factor based on the comparison between the first pressure difference value and the second pressure difference value with the set of calibrated tables at one end of the time window. [18] The method of claim 17, wherein calculating the correction factor comprises: in each of the plurality of time intervals of the time window, incrementing, by the controller, a score for one of the set of calibrated tables in response to the first pressure difference value and the second pressure difference value matching the one of the set of calibrated tables; and Selecting, by the controller, at the end of the time window, a current split corresponding to the set of calibrated tables with a highest score to calculate the correction factor. [19] Aftertreatment system comprising: a first strand comprising one or more first post-treatment components; a second strand comprising one or more second post-treatment components; and a controller configured to: Calculating a first NOx conversion efficiency of the first train; Calculating a second NOx conversion efficiency of the second train; Calculating an average NOx conversion efficiency based on the first NOx conversion efficiency and the second NOx conversion efficiency; Calculating a difference between the first NOx conversion efficiency and the second NOx conversion efficiency; in response to determining that the average NOx conversion efficiency is less than a first threshold or the difference between the first NOx conversion efficiency and the second NOx conversion efficiency is greater than the first threshold, calculating an adjustment factor to balance an estimated first mass flow and an estimated second mass flow; Estimating an adjusted first mass flow of the exhaust gas in the first branch and an adjusted second mass flow of the exhaust gas in the second branch using the adjustment factor; and Adjusting at least one of a reductant dosage, a hydrocarbon dosage, or a soot loading estimate based on the adjusted first mass flow and the adjusted second mass flow. [20] The aftertreatment system of claim 19, wherein in response to determining that the average NOx conversion efficiency is less than the first threshold or the difference between the first NOx conversion efficiency and the second NOx conversion efficiency is greater than the first threshold, the controller is further configured to: identifying a low NOx conversion efficiency train from the first train or the second train based on the calculated first NOx conversion efficiency and the calculated second NOx conversion efficiency; Determining an ammonia (NH3) to NOx ratio (ANR) of the low NOx conversion efficiency train; Comparing the ANR of the low NOx conversion efficiency train with a second threshold; Identifying a NOx slip in response to determining that the ANR of the low NOx conversion efficiency train is less than the second threshold, or an NH3 slip in response to determining that the ANR of the low NOx conversion efficiency train is greater than or equal to the second threshold; and calculating the adjustment factor to adjust a dosing rate of the reductant in the aftertreatment system based on the NOx slip or the NH3 slip. [21] The aftertreatment system of claim 20, wherein to adjust the dosing rate of the reductant, the controller is further configured to increase the dosing rate of the reductant in the aftertreatment system by a first amount in response to the NOx slip or to decrease the dosing rate of the reductant in the aftertreatment system by a second amount in response to the NH3 slip. [22] The aftertreatment system of claim 20, wherein the controller is further configured to: Calculating a third NOx conversion efficiency of the low NOx conversion efficiency train following adjusting the reductant dosing rate; and Readjusting the dosing rate of the reductant in response to determining that the third NOx conversion efficiency is less than a third threshold. [23] The aftertreatment system of claim 22, wherein the controller is further configured to: Calculating a fourth NOx conversion efficiency of the low NOx conversion efficiency train following readjustment of the reductant dosing rate; and Triggering a fault in response to determining that the fourth NOx conversion efficiency is less than a fourth threshold. [24] Method comprising: Calculating, by a controller, a first NOx conversion efficiency of a first train comprising one or more first aftertreatment components; calculating, by the controller, a second NOx conversion efficiency of a second train comprising one or more second aftertreatment components; Calculating, by the controller, an average NOx conversion efficiency based on the first NOx conversion efficiency and the second NOx conversion efficiency; Calculating, by the controller, a difference between the first NOx conversion efficiency and the second NOx conversion efficiency; in response to determining that the average NOx conversion efficiency is less than a first threshold or the difference between the first NOx conversion efficiency and the second NOx conversion efficiency is greater than the first threshold, calculating, by the controller, an adjustment factor to balance an estimated first mass flow and an estimated second mass flow; Estimating, by the controller, an adjusted first mass flow of the exhaust gas in the first branch and an adjusted second mass flow of the exhaust gas in the second branch using the adjustment factor; and Adjusting, by the controller, at least one of a reductant dosage, a hydrocarbon dosage, or a soot loading estimate based on the adjusted first mass flow and the adjusted second mass flow. [25] The method of claim 24, wherein in response to determining that the average NOx conversion efficiency is less than the first threshold or the difference between the first NOx conversion efficiency and the second NOx conversion efficiency is greater than the first threshold, the method further comprises: identifying, by the controller, a low NOx conversion efficiency train from the first train or the second train based on the calculated first NOx conversion efficiency and the calculated second NOx conversion efficiency; Determining, by the controller, an ammonia (NH3) to NOx ratio (ANR) of the low NOx conversion efficiency train; comparing, by the controller, the ANR of the low NOx conversion efficiency train with a second threshold; Identifying, by the controller, a NOx slip in response to determining that the ANR of the low NOx conversion efficiency train is less than the second threshold, or an NH3 slip in response to determining that the ANR of the low NOx conversion efficiency train is greater than or equal to the second threshold; and Calculating, by the controller, the adjustment factor to adjust a dosing rate of the reductant in the aftertreatment system based on the NOx slip or the NH3 slip. [26] The method of claim 25, wherein adjusting the dosing rate of the reducing agent comprises: Increasing, by the controller, the dosing rate of the reductant in the aftertreatment system by a first amount in response to the NOx slip or decreasing, by the controller, the dosing rate of the reductant in the aftertreatment system by a second amount in response to the NH3 slip. [27] The method of claim 25, further comprising: Calculating, by the controller, a third NOx conversion efficiency of the low NOx conversion efficiency train following adjusting the dosing rate of the reductant; and Readjusting, by the controller, the dosing rate of the reductant in response to determining that the third NOx conversion efficiency is less than a third threshold. [28] The method of claim 27, further comprising: Calculating, by the controller, a fourth NOx conversion efficiency of the low NOx conversion efficiency train following readjusting the reductant dosing rate; and triggering, by the controller, a fault in response to determining that the fourth NOx conversion efficiency is less than a fourth threshold.

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