Systems and methods for compensating nox sensor measurements to meet sufficiency requirements

Abstract

This application relates to systems and methods of compensating NOx sensor measurements to meet sufficiency requirements. Systems and methods are provided for diagnosing exhaust aftertreatment systems and mitigating the effects of potential faults in exhaust aftertreatment systems. One method includes receiving, by a controller, data indicative of an amount of at least one of a gain or an offset affecting a sensor in an aftertreatment system; determining, by the controller, a compensation value based on the amount of at least one of the gain or the offset; receiving, by the controller, data indicative of an amount of an exhaust gas constituent in the aftertreatment system; applying, by the controller, the determined compensation value to the data indicative of the amount of the exhaust gas constituent in the aftertreatment system to create compensated data; and initiating, by the controller, an action based on the compensated data.

Description

[0001] This application is a divisional application of the application filed on March 10, 2022, with application number 202280020385.0 and entitled "System and method for compensating NOx sensor measurement results to meet adequacy requirements".

[0002] Cross-references to related applications This application claims priority and interest in U.S. Provisional Patent Application No. 63 / 159,605, filed March 11, 2021, entitled “SYSTEMS AND METHODS FOR COMPENSATING NOX SENSOR MEASUREMENTS TO MEET SUFFICIENCY REQUIREMENTS”, which is incorporated herein by reference in its entirety. Technical Field

[0003] This disclosure relates to diagnosing exhaust aftertreatment systems. More specifically, this disclosure relates to detecting faults in the selective catalytic reduction (SCR) system of an exhaust aftertreatment system via a nitrogen oxide (NOx) sensor. Background Technology

[0004] In recent years, emission regulations for internal combustion engines have become more stringent. Environmental concerns have prompted most parts of the world to impose stricter emission requirements on internal combustion engines. Government agencies, such as the U.S. Environmental Protection Agency (EPA), closely monitor engine emissions and set emission standards that engines must comply with. Therefore, the use of exhaust aftertreatment systems on engines to reduce emissions is becoming increasingly common. Exhaust aftertreatment systems are typically designed to reduce emissions of particulate matter, nitrogen oxides, hydrocarbons, and other pollutants harmful to the environment. Summary of the Invention

[0005] Various aspects of this disclosure may be implemented in one or more of the following embodiments: Project 1): A system for diagnosing exhaust aftertreatment systems and mitigating the effects of potential faults in said exhaust aftertreatment systems, said system comprising: Sensors, which are configured to provide information on the composition of exhaust gases; and One or more processing circuits, comprising one or more memory devices coupled to one or more processors, said one or more memory devices being configured to store instructions thereon, which, when executed by said one or more processors, cause said one or more processors to: Receive information indicating an amount that affects at least one of the gain or offset of the sensor; The compensation value is determined based on the amount of at least one of the gain or the offset; Receive the exhaust gas composition information from the sensor; The determined compensation value is applied to the exhaust gas composition information to create compensated information; and An action is initiated based on the compensated information.

[0006] Project 2): The system according to Project 1), wherein the sensor is a NOx sensor.

[0007] Project 3): The system according to Project 2), wherein the NOx sensor is an engine output NOx sensor or a system output NOx sensor.

[0008] Project 4): The system according to Project 1), wherein the one or more memory devices are further configured to store instructions thereon, which, when executed by the one or more processors, cause the one or more processors to: Based on the compensated information, the low conversion efficiency of the selective catalytic reduction (SCR) system was determined; and In response to determining that the conversion inefficiency of the SCR system exceeds a threshold, a fault indicator for the SCR system is triggered.

[0009] Project 5): The system according to Project 1), wherein the one or more memory devices are further configured to store instructions thereon, which, when executed by the one or more processors, cause the one or more processors to: Based on the compensated information, the low conversion efficiency of the selective catalytic reduction (SCR) system was determined; and In response to determining that the conversion inefficiency of the SCR system exceeds a threshold, the reducing agent feeder of the SCR system is commanded to increase at least one of the feeding frequency or the feeding amount.

[0010] Project 6): The system according to Project 1), wherein the one or more memory devices are further configured to store instructions thereon, which, when executed by the one or more processors, cause the one or more processors to: Determine the compensation gain value; The compensation gain value is determined to be greater than a predefined threshold. Determine the compensation offset value; It is determined that the compensation offset value is greater than a predefined threshold; Compare the compensation gain value and the compensation offset value; When the compensation gain value is greater than the compensation offset value, the compensation gain value is applied to the exhaust gas composition information; and When the compensation offset value is greater than the compensation gain value, the compensation offset value is applied to the exhaust gas composition information.

[0011] Project 7): The system according to Project 1), wherein the one or more memory devices are further configured to store instructions thereon, which, when executed by the one or more processors, cause the one or more processors to: Determine the compensation gain value; It is determined that the compensation gain value is less than a predefined threshold; Determine the compensation offset value; It is determined that the compensation offset value is less than a predefined threshold; Compare the compensation gain value and the compensation offset value; When the compensation gain value is less than the compensation offset value, the compensation gain value is applied to the exhaust gas composition information; and When the compensation offset value is less than the compensation gain value, the compensation offset value is applied to the exhaust gas composition information.

[0012] Project 8): The system according to Project 1), wherein the gain includes high gain and low gain, and The one or more memory devices are further configured to store instructions thereon that, when executed by the one or more processors, cause the one or more processors to: The high gain was determined using an exponentially weighted moving average filter; and The low gain was determined using an exponentially weighted moving average filter.

[0013] Project 9): The system according to Project 8), wherein the one or more memory devices are further configured to store instructions thereon, which, when executed by the one or more processors, cause the one or more processors to: Use at least one of the low gain or the high gain to query the dataset; and The compensation value is determined based on the information returned by the dataset.

[0014] Project 10): The system according to Project 1), wherein the offset includes a high offset and a low offset, and The one or more memory devices are further configured to store instructions thereon that, when executed by the one or more processors, cause the one or more processors to: The high offset was determined using an exponentially weighted moving average filter; and The low offset was determined using an exponentially weighted moving average filter.

[0015] Project 11): A method for diagnosing an exhaust aftertreatment system and mitigating the effects of potential faults in the exhaust aftertreatment system, the method comprising: The controller receives data indicating a quantity that affects at least one of the gain or offset of the sensors in the post-processing system; The controller determines the compensation value based on the amount of at least one of the gain or the offset; The controller receives data indicating the amount of exhaust gas components in the aftertreatment system; The controller applies the determined compensation value to data indicating the amount of the exhaust gas components in the aftertreatment system to create compensated data; and The controller initiates an action based on the compensated data.

[0016] Project 12): The method according to Project 11), wherein the sensor is a NOx sensor.

[0017] Project 13): The method according to Project 12), wherein the NOx sensor is an engine output NOx sensor or a system output NOx sensor.

[0018] Project 14): According to the method described in Project 11), initiating the action further includes: The controller determines the low conversion efficiency of the selective catalytic reduction (SCR) system of the aftertreatment system based on the compensated data; and In response to determining that the conversion inefficiency of the SCR system exceeds a threshold, the controller provides a fault indicator for the SCR system.

[0019] Project 15): According to the method described in Project 11), initiating the action further includes: The controller determines the low conversion efficiency of the selective catalytic reduction (SCR) system of the aftertreatment system based on the compensated data; and In response to determining that the conversion inefficiency of the SCR system exceeds a threshold, the controller commands the reducing agent feeder of the post-processing system to increase at least one of the feeding frequency or the feeding amount.

[0020] Item 16): According to the method described in Item 11), applying the determined compensation value further includes: In response to a situation where the determined compensation value based on at least one of the gain or the offset is higher than a predefined threshold, the controller determines the larger of the determined gain compensation value and the determined offset compensation value; and The controller applies a larger, determined compensation value to the data indicating the amount of NOx in the post-processing system, and the application of the determined compensation value results in compensated data.

[0021] Item 17): According to the method described in Item 11), applying the determined compensation value further includes: In response to the fact that the compensation values ​​determined based on at least one of the gain or the offset are both below a predefined threshold, the controller determines the smaller of the determined gain compensation value and the determined offset compensation value; and The controller applies a smaller, determined compensation value to the data indicating the amount of NOx in the post-processing system, and the application of the determined compensation value results in compensated data.

[0022] Project 18): A system for diagnosing an exhaust aftertreatment system and mitigating the effects of potential faults in the exhaust aftertreatment system, the system comprising: Selective catalytic reduction (SCR) system; Sensors, configured to provide information about the composition of exhaust gases; and The controller is configured as follows: Receive the exhaust gas composition information from the sensor; The compensated information is determined by applying at least one of a compensation offset value or a compensation gain value to the exhaust gas composition information; and An action is initiated based on the compensated information.

[0023] Project 19): The system according to Project 18), wherein the controller is further configured to: Based on the compensated information, the conversion inefficiency of the SCR system is determined; and In response to determining that the conversion inefficiency of the SCR system exceeds a threshold, the reducing agent feeder of the SCR system is commanded to increase at least one of the feeding frequency or the feeding amount.

[0024] Project 20): The system according to Project 18), wherein the controller is further configured to: When the compensation gain value and the compensation offset value are greater than a predetermined threshold and the compensation offset value is greater than the compensation gain value, the compensation offset value is applied to the exhaust gas composition information. When the compensation gain value and the compensation offset value are less than a predetermined threshold and the compensation offset value is less than the compensation gain value, the compensation offset value is applied to the exhaust gas composition information; When the compensation gain value and the compensation offset value are both greater than a predetermined threshold, and the compensation gain value is greater than the compensation offset value, the compensation gain value is applied to the exhaust gas composition information; and When the compensation gain value and the compensation offset value are less than a predetermined threshold and the compensation gain value is less than the compensation offset value, the compensation gain value is applied to the exhaust gas composition information.

[0025] One embodiment relates to a system for diagnosing an exhaust aftertreatment system and mitigating the effects of potential malfunctions in the exhaust aftertreatment system. The system includes a sensor configured to provide exhaust gas composition information, and one or more processing circuits including one or more memory devices coupled to one or more processors, the memory devices being configured to store instructions thereon that, when executed by one or more processors, cause the processors to: receive information indicating an amount affecting at least one of gain or offset of the sensor; determine a compensation value based on the amount of at least one of gain or offset; receive exhaust gas composition information from the sensor; apply the determined compensation value to the exhaust gas composition information to create compensated information; and initiate an action based on the compensated information.

[0026] Another embodiment relates to a method for diagnosing an exhaust aftertreatment system and mitigating the effects of potential faults in the exhaust aftertreatment system. The method includes: receiving data by a controller indicating an amount of at least one of a gain or offset affecting a sensor in the aftertreatment system; determining a compensation value by the controller based on the amount of at least one of the gain or offset; receiving data indicating an amount of exhaust gas components in the aftertreatment system; applying the determined compensation value to the data indicating the amount of exhaust gas components in the aftertreatment system to create compensated data; and initiating an action by the controller based on the compensated data.

[0027] Another embodiment relates to a system for diagnosing exhaust aftertreatment systems and mitigating the effects of potential malfunctions in exhaust aftertreatment systems. The system includes a selective catalytic reduction (SCR) system, a sensor configured to provide exhaust gas composition information, and a controller configured to: receive exhaust gas composition information from the sensor; determine compensated information by applying at least one of a compensation offset value or a compensation gain value to the exhaust gas composition information; and initiate actions based on the compensated information.

[0028] This overview is illustrative only and is not intended to be limiting in any way. Other aspects, inventive features, and advantages of the apparatus or process described herein will become apparent from the detailed description set forth herein in conjunction with the accompanying drawings, wherein like reference numerals refer to like elements. Numerous specific details are provided to give a thorough understanding of embodiments of the subject matter of this disclosure. In one or more embodiments and / or implementations, the features described in this disclosure may be combined in any suitable manner. In this respect, one or more features of one aspect of the invention may be combined with one or more features of different aspects of the invention. Furthermore, additional features that may not be present in all embodiments or implementations may be identified in some embodiments and / or implementations. Attached Figure Description

[0029] Figure 1 It is a graph, according to an exemplary embodiment, showing the estimated SCR inefficiency value as a function of the offset affecting the measurement results or readings from the engine output NOx sensor.

[0030] Figure 2 It is a graph showing the estimated SCR inefficiency value as a function of an exemplary embodiment, which varies with the deviation of the measurement result or reading from the tailpipe NOx sensor.

[0031] Figure 3 It is a graph showing the estimated SCR inefficiency value as a function of an exemplary embodiment, varying with the gain affecting the measurement result or reading from the NOx sensor at the engine output.

[0032] Figure 4 It is a graph showing the estimated SCR inefficiency value as a function of an exemplary embodiment, varying with the gain affecting the measurement results or readings from the tailpipe NOx sensor.

[0033] Figure 5 This is a schematic diagram of a system having a controller according to an exemplary embodiment.

[0034] Figure 6 It is based on an exemplary embodiment. Figure 5 A schematic diagram of the system's controller.

[0035] Figure 7 This is a flowchart of a method for determining a filtered offset value that affects the measurement results or readings from an engine output NOx sensor and a tailpipe NOx sensor, according to an exemplary embodiment.

[0036] Figure 8This is a flowchart of a method for determining a filtered gain value that affects the measurement results or readings from an engine output NOx sensor and a tailpipe NOx sensor, according to an exemplary embodiment.

[0037] Figure 9 This is a flowchart of a method for determining a compensation amount for an engine output NOx sensor reading or measurement result, according to an exemplary embodiment.

[0038] Figure 10 This is a flowchart of a method for determining a compensation amount for a system output NOx sensor reading or measurement result, according to an exemplary embodiment.

[0039] Figure 11 This is a flowchart of a method for prioritizing gain compensation or offset compensation of sensor readings or measurement results, according to an exemplary embodiment. Detailed Implementation

[0040] The following is a more detailed description of various concepts and implementations related to methods, apparatuses, and systems for improving the detection of malfunctioning SCR systems by compensating for offsets and / or gains in NOx sensor outputs (also referred to herein as readings or measurement results). Before turning to the accompanying drawings, which illustrate certain exemplary embodiments in detail, it should be understood that this disclosure is not limited to the details or methods set forth in the specification or shown in the drawings. It should also be understood that the terminology used herein is for descriptive purposes only and should not be considered limiting.

[0041] As environmental regulations become increasingly stringent, consistent aftertreatment system performance is crucial for maintaining vehicle emissions compliance. Consistent aftertreatment system performance depends on the proper functioning of its components; therefore, detecting when these components malfunction (or operate outside acceptable limits) is a critical function. One such aftertreatment system component is the Selective Catalytic Reduction (SCR) system, which converts nitrogen oxides (NOx) in exhaust gases into less harmful nitrogen and water. SCR health can be determined based on conversion efficiency, which refers to the efficiency with which the SCR converts NOx into less harmful elements. One method for determining SCR conversion efficiency is to compare the SCR NOx inlet value with the SCR NOx outlet value. Subsequently, SCR conversion efficiency determination can rely on sensing values ​​from one or more NOx sensors. Therefore, determining whether an SCR system is functioning correctly can depend on the health / operational capability of the NOx sensors.

[0042] Sensors are inherently affected by offset and / or gain. Offset refers to the flat value of the sensed value from the actual value (e.g., a 10°C offset means that an actual temperature of 60°C will be read as 70°C), while gain refers to the percentage by which the sensed value deviates from the actual value (e.g., a 10% or 1.1% gain means that an actual temperature of 60°C will be read as 66°C). Because offset and gain are generally unavoidable for sensors, a certain amount of offset and / or gain is allowed without triggering an error flag for a problematic sensor.

[0043] However, for NOx sensors, a certain amount of offset or gain can negatively impact their ability to diagnose SCR systems (or be used by controllers to diagnose SCR systems). For example, when the NOx sensor offset becomes further negative than -15 ppm (parts per million), the NOx sensor may fail to correctly identify an SCR failure, even if the SCR is actually faulty. This problem becomes even more pronounced with Best Performance Unacceptable (BPU) SCRs—those that convert NOx at technically unacceptable rates but are extremely rare (i.e., possible but still unacceptably best performance). Because these SCRs are close to acceptable efficiency, detecting SCR failure requires a higher level of accuracy and sensitivity, which becomes an even greater problem at certain levels of offset / gain.

[0044] This type of error is called a Type II error or a "false negative," and it can be particularly problematic when the goal is to identify negatives (e.g., detecting a faulty SCR), because a Type II error is a direct failure to identify a negative. For example, when the detection process for a faulty SCR is affected by a Type II error, there is a possibility that the SCR can continue to malfunction without notifying the user, resulting in prolonged non-compliance with emissions regulations. Therefore, it would be advantageous to reduce the number of Type II errors without otherwise affecting the operation of the underlying system or increasing the number of Type I errors (i.e., "false positives").

[0045] Referring generally to the accompanying drawings, the various embodiments disclosed herein relate to systems, apparatus, and methods for improving the detection of a faulty SCR system by compensating for offsets and / or gains in the outputs of NOx sensors. By compensating for offsets / gains affecting one or more NOx sensors, the SCR diagnostic capability of the NOx sensors is improved without affecting, or may not affect, the entire system. As described, the systems and methods of this document receive raw data indicating the amounts of gain and / or offset affecting one or more NOx sensors, convert the raw data into compensation amounts for the NOx sensor outputs, and then apply the compensation based on priority logic. By converting the raw data into a workable output, the systems and methods of this document use the raw data for practical applications: detecting SCR faults.

[0046] Furthermore, the systems and methods described in this paper fundamentally alter the functionality of NOx sensors by addressing the “gap” that impairs their ability to detect SCR faults. As mentioned above, the detection of a faulty SCR relies on both the engine output NOx sensor and the system output NOx sensor. However, if one or more of these NOx sensors experience a certain amount of offset and / or gain, the NOx sensor may fail to detect the fault in the SCR even if it actually is faulty (i.e., a Type II error). This issue is typically addressed by setting a fault flag if the offset / gain reaches an error threshold. However, certain offset / gain values ​​are sufficient to affect the NOx sensor's ability to diagnose SCR faults but insufficient to trigger the NOx sensor fault flag. These specific values ​​of offset / gain are referred to as the NOx gap. By compensating for the offset / gain experienced by the NOx sensor within this NOx gap, the systems and methods described in this paper “shrink” the NOx gap, reducing the frequency of Type II errors. The systems and methods described in this paper directly target the offset / gain that causes the NOx gap and reduce the number of Type II errors without correspondingly increasing Type I errors.

[0047] Figures 1-4 A graph showing the values ​​of SCR catalyst inefficiency determined based on sensor offset / gain according to conventional methods and the system and method described herein. For Figures 1-4For each of these values, the graph values ​​are based on simulations (not field tests) of the following: an engine output NOx of 400 ppm with a standard deviation of 50 ppm (i.e., 400 ppm ± 50 ppm) and an SCR conversion inefficiency of 20% with a standard deviation of 2% (i.e., 20% ± 2%). The SCR conversion inefficiency is calculated by dividing the amount of NOx output by the system (SONOx) by the amount of NOx output by the engine (EONOx), such that the conversion inefficiency is an indication of how much of the NOx output by the engine is not converted (or reduced) by the aftertreatment system.

[0048] Figure 1 Graph 100 shows the estimated SCR inefficiency value as a function of the offset of the measurement result or reading from the engine output NOx sensor. The x-axis of graph 100 represents the engine output NOx sensor offset in ppm, and the y-axis represents the SCR catalyst conversion inefficiency as a percentage, determined based on the engine output NOx sensor. Line 101 plots the SCR conversion inefficiency value based on the engine output sensor, determined using conventional methods, and line 102 plots the SCR conversion inefficiency value based on the engine output sensor, determined using the system and method described herein. As shown, line 101 overestimates the SCR conversion inefficiency at low offsets (i.e., negative values) and underestimates it at high offsets (i.e., positive values). This is because the low offset of EONOx leads conventional methods to determine the SCR conversion inefficiency based on much smaller values ​​of EONOx, which reduces the denominator in the SCR conversion inefficiency calculation and increases the resulting determination. Furthermore, the high offset of EONOx leads conventional methods to determine SCR conversion inefficiencies based on much larger values ​​of EONOx, which increases the denominator in the SCR conversion inefficiency calculation and reduces the obtained determination. In contrast, the system and method described in this paper compensates for the offset (high or low), resulting in the determined SCR conversion inefficiency being closer to the predefined expected range, as described in this paper, of 20% ± 2%.

[0049] Figure 2This is a graph 200 illustrating the estimated SCR inefficiency value as a function of the offset affecting the measurement result or reading of the tailpipe NOx sensor, according to an exemplary embodiment. The x-axis of graph 200 represents the tailpipe NOx sensor offset in ppm, and the y-axis represents the SCR catalyst conversion inefficiency as a percentage, determined based on the tailpipe NOx sensor. Line 201 plots the tailpipe sensor-based SCR conversion inefficiency value determined using conventional methods, and line 202 plots the tailpipe sensor-based SCR conversion inefficiency value determined using the system and methods described herein. As shown, line 201 underestimates the SCR conversion inefficiency at low offsets (i.e., negative values) and overestimates it at high offsets (i.e., positive values). This is because the low offset of SONOx leads conventional methods to determine the SCR conversion inefficiency based on much smaller values ​​of SONOx, which reduces the numerator in the SCR conversion inefficiency calculation and decreases the resulting determination. Furthermore, the high offset of SONOx leads conventional methods to determine SCR conversion inefficiencies based on much larger values ​​of SONOx, which increases the numerator in the SCR conversion inefficiency calculation and the resulting determination. In contrast, the system and method described in this paper compensates for the offset (high or low), resulting in a determined SCR conversion inefficiency that is closer to 20% ± 2%.

[0050] Figure 3This is a graph 300 illustrating the estimated SCR inefficiency value as a function of the gain affecting the measurement result or reading of the engine output NOx sensor, according to an exemplary embodiment. The x-axis of graph 300 represents the engine output NOx sensor gain in factors, and the y-axis represents the SCR catalyst conversion inefficiency as a percentage, determined based on the engine output NOx sensor. Line 301 plots the SCR conversion inefficiency value based on the engine output sensor, determined using conventional methods, and line 302 plots the SCR conversion inefficiency value based on the engine output sensor, determined using the system and methods described herein. As shown, line 301 overestimates the SCR conversion inefficiency at low gain (i.e., factor less than 1) and underestimates it at high gain (i.e., factor greater than 1). This is because the low gain of EONOx leads conventional methods to determine the SCR conversion inefficiency based on much smaller values ​​of EONOx, which reduces the denominator in the SCR conversion inefficiency calculation and increases the resulting determination. Furthermore, the high gain of EONOX leads conventional methods to determine SCR conversion inefficiencies based on much larger values ​​of EONOX. This increases the denominator in the SCR conversion inefficiency calculation and reduces the determined result. Because the effect of gain (low or high) is proportional to the value affected, the overestimation / underestimation of SCR inefficiency in conventional methods is more affected by the gain than by the value of gain itself, resulting in a steeper slope for line 301 than for line 101. In contrast, the system and method described in this paper compensates for the gain (high or low), resulting in a determined SCR conversion inefficiency closer to 20% ± 2%.

[0051] Figure 4This is a graph 400 illustrating the estimated SCR low efficiency value as a function of the gain affecting the measurement result or reading of the tailpipe NOx sensor, according to an exemplary embodiment. The x-axis of graph 400 represents the tailpipe NOx sensor gain in ppm, and the y-axis represents the SCR catalyst conversion low efficiency, determined based on the tailpipe NOx sensor and given as a percentage. Line 401 plots the SCR conversion low efficiency value based on the tailpipe sensor, determined using conventional methods, and line 402 plots the SCR conversion low efficiency value based on the tailpipe sensor, determined using the system and methods described herein. As shown, line 401 underestimates the SCR conversion low efficiency at low gain (e.g., less than 0.95 ppm) and overestimates the SCR conversion low efficiency at high gain (e.g., greater than 1.05 ppm). This is because the low gain of SONOx leads conventional methods to determine the SCR conversion low efficiency based on much smaller values ​​of SONOx, which narrows the numerator of the SCR conversion low efficiency calculation and reduces the resulting determination. Furthermore, the high gain of SONOx leads conventional methods to determine SCR conversion inefficiencies based on much larger values ​​of SONOx, which increases the numerator in the SCR conversion inefficiency calculation and the resulting determination. In contrast, the system and method described in this paper compensate for the gain (high or low), resulting in a determined SCR conversion inefficiency that is closer to 20% ± 2%.

[0052] Now for reference Figure 5 According to an exemplary embodiment, a vehicle 10 with a controller 140 is shown, the controller 140 actively converting information from sensors (e.g., NOx sensors) to diagnose an aftertreatment system or its components. As shown, the vehicle 10 includes an engine 110, an aftertreatment system 120, an operator input / output (I / O) device 130, and a controller 140. The vehicle 10 can be an on-road vehicle or an off-road vehicle, including but not limited to long-haul trucks, medium-duty trucks (e.g., pickup trucks), passenger cars (e.g., sedans, hatchbacks, coupes, etc.), buses, vans, garbage trucks, fire trucks, concrete trucks, transport vehicles, locomotives, marine vehicles, air vehicles, and other types of vehicles. In another embodiment, the vehicle 10 is a stationary device, such as a generator or generator set. Therefore, this disclosure is applicable to a variety of embodiments.

[0053] Components of vehicle 10 can communicate with each other or with external components using any type and any number of wired or wireless connections. For example, wired connections may include serial cables, fiber optic cables, CAT5 cables, or any other form of wired connection. Wireless connections may include the Internet, Wi-Fi, cellular, radio, Bluetooth, ZigBee, etc. In one embodiment, a Controller Area Network (CAN) bus provides the exchange of signals, information, and / or data. The CAN bus includes any number of wired and wireless connections. Because controller 140 is communicatively coupled to the systems and components in vehicle 10, vehicle controller 140 is configured to acquire information about... Figure 5 The operational data and / or OBD capability data of one or more components or systems shown. For example, the operational data may include data on the operating conditions of the powertrain 110 obtained by one or more sensors, such as engine output NOx sensor 127 and system output NOx sensor 128.

[0054] Engine 110 can be any type of internal combustion engine that produces exhaust gases (e.g., a compression ignition engine or a spark ignition engine, which can utilize various fuels such as natural gas, gasoline, diesel fuel, jet fuel, etc.). In another embodiment, the vehicle is at least a partially hybrid vehicle, wherein the power from the internal combustion engine can be replaced and / or supplemented by an electric motor. In any configuration, engine 110 includes one or more cylinders and associated pistons. At this point, air from the atmosphere combines with fuel and burns to drive engine 110. The combustion of fuel and air in the combustion chamber of engine 110 produces exhaust gases that are operably discharged to an exhaust pipe and aftertreatment system 120. In the example shown, engine 110 is configured as an internal combustion engine, particularly a compression ignition engine driven by diesel fuel.

[0055] The aftertreatment system 120 is in exhaust gas receiving communication with the engine 110. The aftertreatment system includes a diesel particulate filter (DPF) 122, a diesel oxidation catalyst (DOC) 121, a selective catalytic reduction (SCR) system 123, an ammonia oxidation catalyst (AMOX) 124, a heater 125, and a DEF feeder 126. The DOC 121 is configured to receive exhaust gas from the engine 110 and oxidize hydrocarbons and carbon monoxide in the exhaust gas, as well as perform other functions, such as oxidizing NO to NO2, to facilitate passive DPF regeneration and rapid SCR reaction. The DPF 122 is arranged or positioned downstream of the DOC 121 and is configured to remove particulate matter, such as soot, from the exhaust gas flowing in the exhaust gas stream. The DPF 122 includes an inlet and an outlet, receiving exhaust gas at the inlet and discharging exhaust gas at the outlet after substantially filtering out particulate matter and / or converting particulate matter into carbon dioxide.

[0056] The aftertreatment system 120 may also include a reductant delivery system, which may include a decomposition chamber (e.g., a decomposition reactor, reactor conduit, decomposition pipe, reactor tube, etc.) to convert the reductant into ammonia. The reductant may be, for example, urea, diesel exhaust fluid (DEF), Adblue®, urea aqueous solution (UWS), aqueous urea solution (e.g., AUS32, etc.), and other similar fluids. Diesel exhaust fluid (DEF) is added to the exhaust gas stream to aid catalytic reduction. The reductant may be injected upstream of the SCR catalyst assembly via a DEF feeder 126, causing the SCR catalyst assembly to receive the mixture of reductant and exhaust gas. The reductant droplets then undergo evaporation, pyrolysis, and hydrolysis processes to form gaseous ammonia within the decomposition chamber, SCR catalyst assembly, and / or exhaust gas conduit system, which exits the aftertreatment system 120. The aftertreatment system 120 may also include an oxidation catalyst (e.g., DOC 121), which is fluidly coupled to the exhaust gas duct system to oxidize hydrocarbons and carbon monoxide in the exhaust gas. To properly facilitate this reduction, the DOC 121 may need to be at a specific operating temperature. In some embodiments, this specific operating temperature is approximately between 200°C and 500°C. In other embodiments, the specific operating temperature is the temperature at which the HC conversion efficiency of the DOC 121 exceeds a predefined threshold (e.g., the conversion of HC to less harmful compounds, referred to as HC conversion efficiency).

[0057] SCR 123 is configured to reduce or at least help reduce NOx emissions by accelerating the NOx reduction process between the DEF from DEF feeder 126 and NOx in the exhaust gas, converting it into nitrogen, water, and / or carbon dioxide. If the SCR catalyst assembly is not at or above a specific temperature, the acceleration of the NOx reduction process is limited, and SCR 123 may not be able to operate at the specified necessary efficiency level. In some embodiments, this specific temperature is approximately 250°C–300°C. The SCR catalyst assembly may be made of a combination of inactive materials and an active catalyst, such that the inactive material (e.g., ceramic metal) directs the exhaust gas to the active catalyst, which is any kind of material suitable for catalytic reduction (e.g., base metal oxides such as vanadium, molybdenum, tungsten, etc.) or noble metals such as platinum). In some embodiments, AMOX 124 is included in the aftertreatment system 120 and is configured to address ammonia slip by removing excess ammonia from the treated exhaust gas before it is released into the atmosphere.

[0058] Because the aftertreatment system 120 treats the exhaust gas before it is released into the atmosphere, some particulate matter or chemicals treated or removed from the exhaust gas can accumulate in the aftertreatment system over time. For example, soot filtered from the exhaust gas by the DPF 122 can accumulate on the DPF 122 over time. Similarly, sulfur particles present in the fuel may accumulate in the SCR 123 and degrade the effectiveness of the SCR catalyst components. Furthermore, DEF undergoing incomplete pyrolysis upstream of the catalyst may accumulate on downstream components of the aftertreatment system 120 and form deposits. However, these accumulations on these components of the aftertreatment system 120 (and the subsequent degradation of effectiveness) may be reversible. In other words, by increasing the temperature of the exhaust gas flowing through the aftertreatment system, soot, sulfur, and DEF deposits can be substantially removed from the DPF 122 and SCR 123, thereby restoring performance (e.g., for the SCR, the conversion efficiency from NOx to N2 and other compounds). These removal processes are referred to as regeneration events and can be performed on the DPF 122, SCR 123, or another component in the aftertreatment system 120 where deposits have formed. However, exposure to high temperatures during active regeneration can degrade the DOC, DPF, and SCR catalysts. Active regeneration events are specifically commanded, for example, when a flow rate measurement via the DPF falls below a predefined threshold indicating partial blockage of the DPF. This, in turn, causes the controller to command a regeneration event, in which exhaust gas temperature increases to raise the DPF temperature and burn off accumulated PM and other components (e.g., increasing engine power output, post-injection, and other means of raising exhaust gas temperature to induce a regeneration event). In contrast, passive regeneration events occur naturally during vehicle operation (e.g., high load conditions that may occur while traversing a hill may cause exhaust gas temperature to rise, and the regeneration event occurs naturally—not specifically commanded).

[0059] In some embodiments, heater 125 is located in the exhaust flow path preceding aftertreatment system 120 and is configured to controllably heat the exhaust gas upstream of aftertreatment system 120. In some embodiments, heater 125 is located directly preceding DOC 121, while in other embodiments, heater 125 is located directly preceding SCR 123 or directly preceding AMOX 124. Heater 125 can be any kind of external heat source, which can be configured to raise the temperature of the passing exhaust gas, which in turn raises the temperature of components in aftertreatment system 120, such as DOC 121 or SCR 123. Thus, heater can be an electric heater, a grille heater, a heater within SCR 123, an induction heater, a microwave oven, or a fuel combustion (e.g., HC fuel) heater. As shown here, heater 125 is an electric heater that draws energy from an energy storage device. Heater 125 can be controlled by controller 140 during active regeneration events to heat the exhaust gas (e.g., by convection). Alternatively, heater can be positioned near a desired component to heat that component (e.g., DPF) by conduction (and possibly convection). Multiple heaters can be used with the exhaust aftertreatment system, and each heater can have the same or different structures (e.g., conduction, convection, etc.).

[0060] Still referencing Figure 5 Operator input / output (I / O) device 130 is also shown. Operator I / O device 130 can be communicatively coupled to controller 140, enabling the exchange of information between controller 140 and I / O device 130, wherein this information may relate to… Figure 5 The determination of one or more components or controllers 140 (as described below). Operator I / O device 130 enables the vehicle operator to communicate with... Figure 5 The controller 140 communicates with one or more components of the vehicle. For example, the operator I / O device 130 may include, but is not limited to, an interactive display, a touch screen device, one or more buttons and switches, a voice command receiver, etc.

[0061] Brief Reference Figure 6As also shown in the figure, one or more sensors are included in the aftertreatment system 120. The sensors are coupled to a controller 140, enabling the controller 140 to monitor and acquire data indicative of the operation of the vehicle 10. In this respect, the sensor array includes at least an engine output NOx sensor 127 and a system output NOx sensor 128. The engine output NOx sensor 127 is located in the exhaust gas flow immediately downstream of the engine 110 and acquires data indicating the amount of NOx at or approximately at its location. The system output NOx sensor 128 is located in the exhaust gas flow immediately downstream of the aftertreatment system 120 and acquires data indicating the amount of NOx at or approximately at its location. It should be understood that the location, number, and type of sensors described are merely illustrative. In other embodiments, different / additional sensors may also be included in the vehicle 10 (e.g., pressure sensors, flow rate sensors, temperature sensors, etc.). Those skilled in the art will understand and recognize the high configurability of the sensors in the vehicle 10.

[0062] because Figure 5 The components are shown as being included in the vehicle 10, therefore the controller 140 can be configured as one or more electronic control units (ECUs). Figure 6 The function and structure of controller 140 are described in more detail.

[0063] Now refer to Figure 6 According to the example embodiment, Figure 5 A schematic diagram of the controller 140 of the vehicle 10. (See diagram below.) Figure 6 As shown, controller 140 includes processing circuitry 205 with processor 204 and memory 206, offset circuitry 220, gain circuitry 222, compensation circuitry 224, priority circuitry 226, and actuator circuitry 228, as well as a communication interface 210. Controller 140 is configured to receive data from one or more virtual sensors indicating the offset or gain affecting one or more NOx sensors, convert that data into compensation values ​​for one or more real sensors, and then take action based on applying that compensation to the output from one or more real sensors. Specifically, controller 140 may apply compensation to the system output NOx sensor 128 to reduce the likelihood of Type II errors when diagnosing SCR 123 faults by decreasing the “NOx gap.” Furthermore, while the controller 140 is primarily referenced to determine the compensation values ​​for one or more NOx sensors for diagnosing SCR 123, the systems and methods described herein should be understood to be applicable to any exhaust gas composition (e.g., soot, sulfur oxides, hydrocarbons, etc.) and corresponding sensors (e.g., pressure sensors, flow sensors, etc.).

[0064] In one configuration, offset circuitry 220, gain circuitry 222, compensation circuitry 224, priority circuitry 226, and actuator circuitry 228 are implemented as a machine- or computer-readable medium storing instructions executable by a processor such as processor 204. As described herein and in other uses, the machine-readable medium facilitates the performance of certain operations to achieve the reception and transmission of data. For example, the machine-readable medium can provide instructions (e.g., commands, etc.) to, for example, acquire data. In this regard, the machine-readable medium may include programmable logic defining the frequency of data acquisition (or data transmission). The computer-readable medium instructions may include code, which can be written in any programming language, including but not limited to Java and any conventional procedural programming language, such as the "C" programming language or similar programming languages. The computer-readable program code can be executed on one processor or multiple remote processors. In the latter case, the remote processors can be interconnected via any type of network (e.g., CAN bus, etc.).

[0065] In another configuration, offset circuit 220, gain circuit 222, compensation circuit 224, priority circuit 226, and actuator circuit 228 are implemented as hardware units, such as electronic control units. Therefore, offset circuit 220, gain circuit 222, compensation circuit 224, priority circuit 226, and actuator circuit 228 can be implemented as one or more circuit components, including but not limited to processing circuitry, network interfaces, peripherals, input devices, output devices, sensors, etc. In some embodiments, offset circuit 220, gain circuit 222, compensation circuit 224, priority circuit 226, and actuator circuit 228 can take the form of one or more analog circuits, electronic circuits (e.g., integrated circuits (ICs), discrete circuits, system-on-a-chip (SoC) circuits, microcontrollers, etc.), telecommunications circuits, hybrid circuits, and any other type of "circuit". In this respect, offset circuit 220, gain circuit 222, compensation circuit 224, priority circuit 226, and actuator circuit 228 can include any type of component for performing or facilitating the implementation of the operations described herein. For example, the circuit 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. Offset circuit 220, gain circuit 222, compensation circuit 224, priority circuit 226, and actuator circuit 228 may also include programmable hardware devices, such as field-programmable gate arrays, programmable array logic, programmable logic devices, etc. Offset circuit 220, gain circuit 222, compensation circuit 224, priority circuit 226, and actuator circuit 228 may include one or more memory devices for storing instructions executable by a processor of offset circuit 220, gain circuit 222, compensation circuit 224, priority circuit 226, and actuator circuit 228. One or more memory devices and a processor may have the same definitions as provided below regarding memory 206 and processor 204. In some hardware unit configurations, the offset circuit 220, gain circuit 222, compensation circuit 224, priority circuit 226, and actuator circuit 228 may be geographically distributed across various locations within the vehicle. Alternatively, as shown, the offset circuit 220, gain circuit 222, compensation circuit 224, priority circuit 226, and actuator circuit 228 may be contained within a single unit / housing, which is shown as controller 140.

[0066] In the illustrated example, controller 140 includes processing circuitry 205 having processor 204 and memory 206. Processing circuitry 205 may be constructed or configured to execute or implement the instructions, commands, and / or control processes described herein with respect to offset circuitry 220, gain circuitry 222, compensation circuitry 224, priority circuitry 226, and actuator circuitry 228. The depicted configuration represents offset circuitry 220, gain circuitry 222, compensation circuitry 224, priority circuitry 226, and actuator circuitry 228 as a machine or computer-readable medium storing instructions. However, as noted above, this illustration is not intended to be limiting, as other embodiments are contemplated in this disclosure, wherein at least one circuit of offset circuitry 220, gain circuitry 222, compensation circuitry 224, priority circuitry 226, and actuator circuitry 228, or offset circuitry 220, gain circuitry 222, compensation circuitry 224, priority circuitry 226, and actuator circuitry 228, is configured as a hardware unit. All such combinations and variations are intended to fall within the scope of this disclosure.

[0067] Processor 204 may be implemented as a single-chip or multi-chip processor, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA) or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described herein. The processor may be a microprocessor. The processor may also be implemented as a combination of computing devices, such as a combination of a DSP and a microprocessor, multiple microprocessors, one or more microprocessors combined with a DSP core, or any other such configuration. In some embodiments, one or more processors may be shared by multiple circuits (e.g., offset circuitry 220, gain circuitry 222, compensation circuitry 224, priority circuitry 226, and actuator circuitry 228 may include or otherwise share the same processor, which in some example embodiments may execute instructions stored or otherwise accessed via different regions of memory). Alternatively or additionally, the one or more processors may be configured to perform or otherwise perform certain operations independently of one or more coprocessors. In other example embodiments, two or more processors may be coupled via a bus to enable independent, parallel, pipelined, or multithreaded instruction execution. All these variations are intended to fall within the scope of this disclosure.

[0068] Memory 206 (e.g., memory, memory cell, storage device) may include one or more devices (e.g., RAM, ROM, flash memory, hard disk storage) for storing data and / or computer code to perform or facilitate the various processes, layers, and modules described herein. Memory 206 may be communicatively connected to processor 204 to provide processor 204 with computer code or instructions for performing at least some of the processes described herein. Furthermore, memory 206 may be or include tangible, non-transient volatile memory or non-volatile memory. Therefore, memory 206 may include database components, object code components, scripting components, or any other type of information structure for supporting the various activities and information structures described herein.

[0069] Communication interface 210 may include any combination of wired and / or wireless interfaces (e.g., jacks, antennas, transmitters, receivers, transceivers, wired terminals) for data communication with various systems, devices, or networks configured to enable in-vehicle communication (e.g., communication between vehicle components) and out-of-vehicle communication (e.g., communication with a remote server). For example, regarding out-of-vehicle / system communication, communication interface 210 may include an Ethernet card and port for sending and receiving data via an Ethernet-based communication network, and / or a Wi-Fi transceiver for communication via a wireless communication network. Communication interface 210 may be configured to communicate via a local area network or a wide area network (e.g., the Internet) and may use various communication protocols (e.g., IP, LON, Bluetooth, ZigBee, radio, cellular, near-field communication).

[0070] Offset circuit 220 is configured to receive raw data indicative of the offset affecting engine output NOx sensor 127 and / or system output NOx sensor 128, transform the raw data, and output a filtered offset value. The raw data indicative of the offset affecting engine output NOx sensor 127 and / or system output NOx sensor 128 may be received based on one or more real or virtual sensors that estimate the NOx amount at different points throughout the aftertreatment system 120 and set the offset based on a comparison between the virtual sensor output and the real sensor output (i.e., from engine output NOx sensor 127 and / or system output NOx sensor 128). These offset values ​​can be high or low. A high offset value indicates that the sensed NOx value is higher than the actual (i.e., estimated) NOx value, such that a positive offset value (i.e., >0) is subtracted from the sensed value. A low offset value indicates that the sensed NOx value is lower than the actual NOx value, such that a negative offset value (i.e., <0) is subtracted from the sensed value.

[0071] From there, offset circuit 220 transforms the raw data into usable information, data, or values ​​for resolving NOx gaps. In some embodiments, this transformation is accomplished using an exponentially weighted moving average (EWMA) filter, which improves the usability of the raw dataset and distills the entire dataset down to a single value. The EWMA filter continuously takes the average (i.e., moving average) of a specific value (e.g., the NOx offset) over time and applies a weighting factor to the most recent value, which decreases exponentially as the value becomes less recent. In this way, the most recent value (e.g., from the last...) becomes... x The value in minutes or hours, or the last x In moving average calculations, a value (of less recent origin) is considered more valuable than a less recent value (e.g., one from over [a certain period]). x Values ​​from minutes or hours ago, or compared to the last x Earlier values ​​receive exponentially more weight, smoothing the dataset by reducing the impact of noise in the data and emphasizing the most recently sampled data points.

[0072] Once the EWMA filter is applied, the filtered offset values ​​are output by the offset circuit 220. In some embodiments, the offset circuit 220 outputs a total of four filtered offset values: a filtered high offset value and a filtered low offset value for the engine output NOx sensor 127, and a filtered high offset value and a filtered low offset value for the system output NOx sensor 128. Although the sensor may only experience a high or low offset at any given instant (i.e., the sensed value cannot be higher and lower than the actual value simultaneously), because the EWMA filter samples the offset values ​​over a period of time, and the engine output NOx sensor 127 and / or the system output NOx sensor may experience both high and low offsets over a period of time, the offset circuit 220 outputs a filtered high offset value and a filtered low offset value for each sensor.

[0073] Figure 7 This is a flowchart of a method 700, according to an exemplary embodiment, for determining a filtered offset value that affects measurement results or readings from an engine output NOx sensor and a tailpipe NOx sensor. Figure 7As shown, method 700 begins at one of blocks 711 to 714. At 711, controller 140 receives data indicating a high offset affecting the system output NOx sensor 128. From there, controller 140 applies an EWMA filter at 721, which at 731 outputs a filtered high offset value for the system output NOx sensor 128. At 712, controller 140 receives data indicating a low offset affecting the system output NOx sensor 128. From there, controller 140 applies an EWMA filter at 722, which at 732 outputs a filtered low offset value for the system output NOx sensor 128. At 713, controller 140 receives data indicating a high offset affecting the engine output NOx sensor 127. From there, controller 140 applies an EWMA filter at 723, which at 733 outputs a filtered high offset value for the engine output NOx sensor 127. At 714, controller 140 receives data indicating a low offset affecting the engine output NOx sensor 127. From there, controller 140 applies an EWMA filter at 724, which at 734 outputs a filtered low offset value to engine output NOx sensor 127.

[0074] Gain circuit 222 is configured to receive raw data indicative of the gain affecting engine output NOx sensor 127 and / or system output NOx sensor 128, transform the raw data, and output a filtered gain value. The raw data indicative of the gain affecting engine output NOx sensor 127 and / or system output NOx sensor 128 may be received based on one or more virtual or real sensors that estimate the amount of NOx at different points throughout the aftertreatment system 120, and the gain amount is set based on a comparison between the virtual sensor output and the actual sensor output (i.e., the actual sensor output from engine output NOx sensor 127 and / or system output NOx sensor 128). These gain values ​​can be high or low. A high gain value indicates that the sensed NOx value is higher than the actual (i.e., estimated) NOx value, such that the sensed value will be divided by a positive gain value (i.e., >1). A low gain value indicates that the sensed NOx value is lower than the actual NOx value, such that the sensed value will be divided by a negative gain value (i.e., <1).

[0075] From there, gain circuit 222 transforms the raw data into usable information, data, or values ​​for addressing the NOx gap. In some embodiments, this transformation is accomplished using an exponentially weighted moving average (EWMA) filter, which improves the usability of the raw dataset and extracts the entire dataset to a single value. The EWMA filter continuously takes the average (i.e., moving average) of a specific value (e.g., the NOx gain) over time and applies a weighting factor to the most recent value (e.g., from the last...). x The value in minutes or hours, or the lastx (a number of values), the weighting factor becomes less recent as the value becomes less recent (e.g., from more than [number] values). x Values ​​from minutes or hours ago, or compared to the last x The weight of the most recent value decreases exponentially compared to less recent values ​​in the moving average calculation. In this way, the most recent value receives exponentially more weight in the moving average calculation than less recent values, smoothing the dataset by reducing the impact of noise in the data and emphasizing the most recently sampled data points.

[0076] Once the EWMA filter is applied, the gain circuit 222 outputs a filtered gain value. In some embodiments, the gain circuit 222 outputs a total of four filtered gain values: a filtered high gain value and a filtered low gain value for the engine output NOx sensor 127, and a filtered high gain value and a filtered low gain value for the system output NOx sensor 128. Although the sensor may only experience high or low gain at any given instant (i.e., the sensed value cannot be simultaneously higher or lower than the actual value), because the EWMA filter samples the gain value over a period of time, and the engine output NOx sensor 127 and / or the system output NOx sensor may experience both high and low gain over a period of time, the gain circuit 222 outputs a filtered high gain value and a filtered low gain value for each sensor. The filtered high gain value indicates the amount of high gain affecting the readings and measurements from the engine output NOx sensor 127 and the system output NOx sensor 128, such that the filtered high gain value is an estimate that the current readings and measurements overstate or overestimate the amount of NOx in the exhaust gas. The filtered low-gain value indicates a low gain that affects the readings and measurements from the engine output NOx sensor 127 and the system output NOx sensor 128, making the filtered low-gain value an estimate that the current readings and measurements underreport or underestimate the amount of NOx in the exhaust gas. Thus, both the filtered high-gain value and the filtered low-gain value provide an improved assessment of how the engine output NOx sensor 127 and the system output NOx sensor 128 may inaccurately measure the amount of NOx in the exhaust gas.

[0077] Figure 8 This is a flowchart of a method 800, according to an exemplary embodiment, for determining a filtered gain value that affects measurement results or readings from an engine output NOx sensor and a tailpipe NOx sensor. Figure 8As shown, method 800 begins with one of blocks 811 to 814. At 811, controller 140 receives data indicating a high-gain amount affecting system output NOx sensor 128 based on one or more virtual or real sensors that estimate the NOx amount at different points throughout the aftertreatment system 120, and sets the gain amount based on a comparison between the virtual sensor output and the actual sensor output (i.e., the actual sensor output from engine output NOx sensor 127 and / or system output NOx sensor 128). From there, controller 140 applies an EWMA filter at 821, which at 831 outputs a filtered high-gain value for system output NOx sensor 128. At 812, controller 140 receives data indicating a low-gain amount affecting system output NOx sensor 128. From there, controller 140 applies an EWMA filter at 822, which at 832 outputs a filtered low-gain value for system output NOx sensor 128. At 813, controller 140 receives data indicating a high-gain amount affecting engine output NOx sensor 127. From there, controller 140 applies an EWMA filter at 823, which outputs a filtered high-gain value to engine output NOx sensor 127 at 833. At 814, controller 140 receives data indicating the amount of low gain affecting engine output NOx sensor 127. From there, controller 140 applies an EWMA filter at 824, which outputs a filtered low-gain value to engine output NOx sensor 127 at 834.

[0078] Compensation circuit 224 is configured to receive the outputs from offset circuit 220 and gain circuit 222, and convert the filtered outputs into a compensation value. The compensation value is the amount by which the change in reading or measurement caused by offset and / or gain is reversed when applied to a reading or measurement from engine output NOx sensor 127 or system output NOx sensor 128. Compensation circuit 224 operates for engine output NOx sensor 127 and system output NOx sensor 128, respectively. In some embodiments, compensation circuit 224 is configured to determine different compensation values ​​for different operations (e.g., diagnosing the health of SCR 123, actuating DEF feeder 126, etc.). For example, compensation circuit 224 may determine a first compensation value applied to system output NOx sensor 128 to diagnose SCR 123, and a second compensation value applied to engine output NOx sensor 127 to actuate DEF feeder 126.

[0079] In some embodiments, the compensation circuit 224 transforms the filtered output by feeding the filtered output from the offset circuit 220 and the gain circuit 222 into a lookup table and associating the filtered output with a compensation value. The lookup table associates the filtered gain / offset value with a compensation value less than the filtered gain / offset value to avoid overcompensation. For example, if the filtered offset value is -15 ppm, the lookup table may associate it with a compensation value of -12 ppm. In another example, if the filtered gain value is 1.35, the lookup table may associate it with a compensation value of 1.27.

[0080] Once the compensation circuit 224 has converted the filtered output into a compensation value, it applies the compensation value to the sensing output of the NOx sensor. For offset-based compensation, the compensation circuit 224 subtracts the compensation value associated with the filtered high offset value and the filtered low offset value from the sensed NOx value (for engine output NOx sensor 127 or system output NOx sensor 128). For gain-based compensation, the compensation circuit 224 divides the sensed NOx value (for engine output NOx sensor 127 or system output NOx sensor 128) by the compensation value associated with the filtered high gain value and the filtered low gain value. These applied compensation values ​​(i.e., the offset-based compensation value applied to engine output NOx sensor 127, the gain-based compensation value applied to engine output NOx sensor 127, the offset-based compensation value applied to system output NOx sensor 128, and the gain-based compensation value applied to system output NOx sensor 128) are then fed to the priority circuit 226.

[0081] As described above, in some embodiments, the compensation circuit 224 determines different compensation values ​​depending on the application. These different compensation values ​​arise from the use of different lookup tables, such that the compensation circuit 226 utilizes a first lookup table for SCR diagnostic applications and a second lookup table for DEF feeder 126 commands. For example, when used in SCR diagnostic applications, there is a greater concern about overcompensation due to the costs associated with excessively frequent maintenance, so the lookup table more conservatively associates the compensation value with a filtered gain / offset value (i.e., a compensation value lower than the filtered gain / offset value). However, when used to adjust the operation of the DEF feeder 126, the cost of overcompensation is lower because overcompensation only results in errors in the DEF feed, which can be mitigated (e.g., AMOX 124, regeneration events, etc.). Therefore, the second lookup table for DEF feeding associates the compensation value with a filtered gain / offset value that is closer to the filtered value.

[0082] Figure 9This is a flowchart of a method 900 for determining a compensation amount for an engine output NOx sensor 127, according to an exemplary embodiment. Method 900 begins at one of blocks 911 to 914. At 911, controller 140 receives a filtered high offset value from the engine output (from process 733) and at 921 associates the offset value with a compensation value from a lookup table. At 912, controller 140 receives a filtered low offset value from the engine output (from process 734) and at 922 associates the offset value with a compensation value from the lookup table. Then at 931, the values ​​from 921 and 922 are subtracted from the sensed output from the engine output NOx sensor 127 at 933. At 913, controller 140 receives a filtered high gain value from the engine output (i.e., from 833) and at 923 associates the gain value with a compensation value from the lookup table. At 914, controller 140 receives a filtered low-gain value from the engine output (i.e., from 834) and at 924 associates the gain value with a compensation value from a lookup table. Then at 932, the sensed output from engine output NOx sensor 127 from 933 is divided by the values ​​from 923 and 924. At block 941, the resulting values ​​from 931 and 932 are fed to priority logic (i.e., priority circuitry 226). Priority logic 941 may be notified by calibration override priority from 942, which adjusts the priority logic based on the expected application of compensation (e.g., if vehicle 10 is intended for low EONOX operation, offset-based compensation takes precedence over gain-based compensation, etc.). The output of the priority logic at 941 is fed to the actuator at block 951, where controller 140 takes one or more actions based on the output of the priority logic. These actions, one or more, include: a) applying a compensation value to the sensing output of at least one of the engine output NOx sensor 127 and the system output NOx sensor 128 to generate a compensated NOx value; b) issuing a fault code for at least one of the engine output NOx sensor 127, the system output NOx sensor, or the SCR 123; c) sending a command to the DEF feeder 126 to start feeding or adjust the feed rate; d) sending a command to influence the post-injection fueling event of the engine 110 to change the exhaust gas temperature; and / or e) sending a command to turn on or adjust the output of the heater 125 to change the exhaust gas temperature.

[0083] Figure 10This is a flowchart of a method 1000 for determining a compensation amount for a system output NOx sensor 128 according to an exemplary embodiment. Method 1000 begins at one of blocks 1011 to 1014. At 1011, controller 140 receives a filtered high offset value from the system output (from process 731) and associates the offset value with a compensation value from a lookup table at 1021. At 1012, controller 140 receives a filtered low offset value from the system output (from process 732) and associates the offset value with a compensation value from a lookup table at 1022. Then at 1031, the values ​​from 1021 and 1022 are subtracted from the sensed output from the system output NOx sensor 128 at 1033. At 1013, controller 140 receives a filtered high gain value from the system output (from process 831) and associates the gain value with a compensation value from a lookup table at 1023. At 1014, controller 140 receives the filtered low-gain value of the system output (from process 832), and at 1024 associates the gain value with a compensation value from a lookup table. Then, at 1032, the sensing output from the system output NOx sensor 128 from 1033 is divided by the values ​​from 1023 and 1024 (i.e., the sensing output (A) is the filtered low-gain value). B ) and filtered high gain value ( C Dividing the two, such that the operation performed on 1032 can be given as In block 1041, the resulting values ​​from 1031 and 1032 are fed to priority logic (i.e., priority circuitry 226). Priority logic 1041 may be notified by a calibration override priority from 1042, which adjusts the priority logic based on the expected application of compensation (e.g., if vehicle 10 is intended for low EONOX operation, offset-based compensation will take precedence over gain-based compensation, etc.). The output of the priority logic at 1041 is fed to the actuator at block 1051, where controller 140 takes one or more actions based on the output from the priority logic. These actions, one or more, include: a) applying a compensation value to the sensing output of at least one of the engine output NOx sensor 127 and the system output NOx sensor 128 to generate a compensated value for NOx; b) issuing a fault code for at least one of the engine output NOx sensor 127, the system output NOx sensor, or the SCR 123; c) sending a command to the DEF feeder 126 to start feeding or adjust the feed rate; d) sending a command to influence the post-injection refueling event of the engine 110 to change the exhaust gas temperature; and / or e) sending a command to turn on or adjust the output of the heater 125 to change the exhaust gas temperature.

[0084] Priority circuit 226 is configured to receive applied compensation values ​​from compensation circuit 224 and determine which applied compensation value is best suited for guiding controller 140. In other words, priority circuit 226 determines which of the gain or offset values ​​has the greatest impact on the sensor output and, based on that determination, causes one or more actions, as described herein. For engine output NOx sensor 127, priority circuit 226 receives both the offset-based and gain-based applied compensation values ​​for engine output NOx sensor 127. If both applied compensation values ​​are high (e.g., offset > 0, gain > 1) because both values ​​exceed predefined thresholds, priority circuit 226 determines which of the gain or offset values ​​has a greater impact on engine output NOx sensor 127. To determine which has a greater impact, priority circuit 226 receives an estimate of the engine output NOx from the virtual sensor and applies offset-based compensation (i.e., the estimated NOx is added to the offset-based compensation value from offset circuit 220) and gain-based compensation (i.e., the estimated NOx is multiplied by the gain-based compensation value from gain circuit 222). If the applied offset estimate is greater than the applied gain estimate, priority circuit 226 determines that the offset has a greater impact on engine output NOx sensor 127 and passes this determination to actuator circuit 228. Alternatively, if the applied gain estimate is greater than the applied offset estimate, priority circuit 226 determines that the gain has a greater impact on engine output NOx sensor 127 and passes this determination to actuator circuit 228.

[0085] If both applied compensation values ​​are low (e.g., offset < 0, gain < 1) based on both values ​​being below a predefined threshold, priority circuit 226 determines which of the gain or offset has a greater impact on engine output NOx sensor 127. To determine which has a greater impact, priority circuit 226 receives an estimate of engine output NOx from the virtual sensor and applies offset-based compensation (i.e., the estimated NOx plus the offset-based compensation value from offset circuit 220) and gain-based compensation (i.e., the estimated NOx multiplied by the gain-based compensation value from gain circuit 222). Then, if the applied offset estimate is smaller than the applied gain estimate (i.e., more negative), priority circuit 226 determines that the offset has a greater impact on engine output NOx sensor 127 and passes this determination to actuator circuit 228. Alternatively, if the applied gain estimate is smaller than the applied offset estimate (i.e., more negative), priority circuit 226 determines that the gain has a greater impact on engine output NOx sensor 127 and passes this determination to actuator circuit 228.

[0086] However, if the two applied compensation values ​​are misaligned (i.e., one is low and the other is high), priority circuit 226 determines that no compensation is needed, thus not providing compensation commands for the engine output NOx sensor 127 to actuator circuit 228. For example, if the gain is high (i.e., >1) but the offset is low (i.e., <0), it indicates a problem with the basic determination because priority circuit 226 cannot determine which effect is greater if the effects are in different directions. In this case, controller 140 takes no action and returns to the initial sampling step of offset circuit 220 and gain circuit 222.

[0087] A similar method is performed on the system output NOx sensor 128. Priority circuit 226 receives both the applied offset-based compensation value and the applied gain-based compensation value for the system output NOx sensor 128. If both applied compensation values ​​are high (i.e., offset > 0, gain > 1), priority circuit 226 determines which of the two—gain or offset—has a greater impact on the system output NOx sensor 128. To determine which has a greater impact, priority circuit 226 receives an estimate of the system output NOx from the dummy sensor and applies offset-based compensation (i.e., the estimated NOx plus the offset-based compensation value from offset circuit 220) and gain-based compensation (i.e., the estimated NOx multiplied by the gain-based compensation value from gain circuit 222). If the applied offset estimate is greater than the applied gain estimate, priority circuit 226 determines that the offset has a greater impact on the system output NOx sensor 128 and passes this determination to actuator circuit 228. Alternatively, if the applied gain estimate is greater than the applied offset estimate, the priority circuit 226 determines that the gain has a greater impact on the system output NOx sensor 128 and passes this determination to the actuator circuit 228.

[0088] If both applied compensation values ​​are low (i.e., offset < 0, gain < 1), priority circuit 226 determines which of the gain or offset has a greater impact on the system output NOx sensor 128. To determine which has a greater impact, priority circuit 226 receives an estimate of the system output NOx from the virtual sensor and applies offset-based compensation (i.e., the estimated NOx value from the virtual sensor plus the offset-based compensation value from offset circuit 220) and gain-based compensation (i.e., the estimated NOx value from the virtual sensor multiplied by the gain-based compensation value from gain circuit 222). Then, if the applied offset estimate is smaller than the applied gain estimate (i.e., more negative), priority circuit 226 determines that the offset has a greater impact on the system output NOx sensor 128 and passes this determination to actuator circuit 228. Alternatively, if the applied gain estimate is smaller than the applied offset estimate (i.e., more negative), priority circuit 226 determines that the gain has a greater impact on the system output NOx sensor 128 and passes this determination to actuator circuit 228.

[0089] However, if the two applied compensation values ​​are misaligned (i.e., one is low and the other is high), the priority circuit 226 determines that no compensation is passed to the actuator circuit 228 for use in the system output NOx sensor 128. For example, if the gain is high (i.e., >1) but the offset is low (i.e., <0), it indicates a problem with the basic decision, because if the effects are in different directions, the priority circuit 226 cannot determine which effect is greater.

[0090] Similar to compensation circuit 224, priority circuit 226 can modify its decision logic based on the application. For example, if vehicle 10 is intended to comply with stricter emission regulations (e.g., <0.02 or 0.05 g / bhp-hr NOx), priority circuit 226 applies offset-based compensation instead of gain-based compensation, regardless of which applied estimate is larger (or smaller). Similarly, if vehicle 10 is equipped for low EONOx (i.e., with a lean-burn engine), priority circuit 226 applies offset-based compensation instead of gain-based compensation, regardless of the comparison result of the applied estimates.

[0091] Figure 11 This is a flowchart of a method 1100 for prioritizing gain compensation or offset compensation according to an exemplary embodiment. Figure 11As shown, method 1100 begins at block 1110, where controller 140 receives a compensation value applied for offset (e.g., from 931 or 1031) and a compensation value applied for gain (e.g., from 932 or 1032). At 1120, controller 140 determines whether the offset-based compensation is greater than 0 (i.e., high offset) and whether the gain-based compensation is greater than 1 (i.e., high gain). If not, method 1100 proceeds to block 1130 (1120: No). If yes, method 1100 proceeds to block 1122 (1120: Yes), where controller 140 determines that the sensor in question (engine output NOx sensor 127 or system output NOx sensor 128) should be compensated high (i.e., the NOx sensor is in the low range). From there, controller 140 at 1124 applies each of the gain compensation and offset compensation to the estimated NOx from the dummy sensor at 1115. If the offset compensation estimate is greater than the gain compensation estimate, then method 1100 proceeds to 1126, where controller 140 determines to apply offset compensation (1124: Yes). Alternatively, if the gain compensation estimate is greater than the offset compensation estimate, then method 1128 proceeds to 1128, where controller 140 determines to apply gain compensation (1124: No).

[0092] At 1130 (1120: No), controller 140 determines whether the offset-based compensation is less than a predefined threshold indicating low offset (e.g., 0) and whether the gain-based compensation is less than a predefined threshold indicating low gain (e.g., 1). If not, method 1100 proceeds to block 1140 (1130: No). If yes, method 1100 proceeds to block 1132 (1130: Yes), where controller 140 determines that the sensor in question (engine output NOx sensor 127 or system output NOx sensor 128) should be under-compensated (i.e., the NOx sensor is in the high range). From there, controller 140 at 1134 applies each of the gain compensation and offset compensation to the NOx estimate from the dummy sensor from 1115. If the offset compensation estimate is smaller than the gain compensation estimate (i.e., more negative), method 1100 proceeds to 1136, where controller 140 determines to apply offset compensation (1134: Yes). Alternatively, if the gain compensation estimate is smaller than the offset compensation estimate (i.e., more negative), the method proceeds to 1138, where controller 140 determines to apply gain compensation (1134: No). If method 1100 proceeds to block 1140, controller 140 determines not to apply compensation because there is a contradiction between one of the gain or offset being high and the other of the offset or gain being low.

[0093] Actuator circuit 228 is configured or constructed to receive determinations from priority circuit 226 and take one or more actions based on those determinations. These actions include: a) applying a compensation value to the sensed output of at least one of engine output NOx sensor 127 and system output NOx sensor 128 to generate a compensated value for NOx; b) issuing a fault code for at least one of engine output NOx sensor 127, system output NOx sensor, or SCR 123; c) sending a command to DEF feeder 126 to start feeding or adjust the feed rate; d) sending a command to influence the post-injection refueling event of engine 110 to change the exhaust gas temperature; and / or e) sending a command to turn on or adjust the output of heater 125 to change the exhaust gas temperature.

[0094] For example, when actuator circuit 228 compensates engine output NOx sensor 127 based on high offset or high gain, resulting in a lower NOx value sensed after the compensation value is applied, actuator circuit 228 commands less feed from DEF feeder 126 due to the lower NOx value, which reduces overall DEF consumption. When actuator circuit 228 compensates engine output NOx sensor 127 based on low offset or low gain, resulting in a higher NOx value sensed after the compensation value is applied, actuator circuit 228 commands less feed from DEF feeder 126, thereby reducing overall DEF consumption. When actuator circuit 228 compensates system output NOx sensor 128 based on high offset or high gain, resulting in a lower NOx value sensed after the compensation value is applied, actuator circuit 228 commands less feed from DEF feeder 126, thereby reducing overall DEF consumption.

[0095] Furthermore, by applying a compensation value to the sensing output from at least one of the engine output NOx sensor 127 or the system output NOx sensor 128, the actuator circuit 228 compensates for the offset (or gain) so that the engine output NOx sensor 127 and the system output NOx sensor 128 can operate with a substantially non-substantial offset / gain (or with an acceptable amount of offset / gain), thereby reducing the likelihood that the faulty SCR 123 will not be detected due to NOx sensor offset (or gain). Thus, the compensated data provides a more accurate determination of the SCR conversion inefficiency (i.e., SONOx / EONOx), enabling the controller 140 to handle instances of Type II errors when a faulty SCR 123 is detected.

[0096] As used herein, the terms “approximately,” “about,” “substantially,” and similar terms are intended to have a broad meaning consistent with common and accepted usage by those skilled in the art to which the subject matter of this disclosure relates. Those skilled in the art, upon review of this disclosure, will understand that these terms are intended to allow for the description of certain features described and claimed, without limiting the scope of those features to the precise numerical ranges provided. Therefore, these terms should be interpreted as indicating that non-substantial or irrelevant modifications or alterations to the described and claimed subject matter are considered to be within the scope of the disclosure set forth in the appended claims.

[0097] It should be noted that the terms “exemplary” and their variations used herein to describe various embodiments are intended to indicate that these embodiments are possible examples, representations or illustrations of possible embodiments (and these terms are not intended to imply that these embodiments are necessarily special or superlative examples).

[0098] As used herein, the term "coupled" and its variations refer to two components being directly or indirectly connected to each other. This connection can be static (e.g., permanent or fixed) or movable (e.g., removable or releasable). Such a connection can be achieved by directly coupling two components to each other, by coupling two components to each other using one or more separate intervening components, or by coupling two components to each other using an intervening component that forms a single integral body with one of the two components. If "coupled" or its variations are modified by an additional term (e.g., directly coupled), the general definition of "coupled" provided above is modified by the simple linguistic meaning of the additional term (e.g., "directly coupled" means a connection of two components without any separate intervening component), resulting in a narrower definition than the general definition of "coupled" provided above. This coupling can be mechanical, electrical, or fluid. For example, circuit A communicatively "coupled" to circuit B can mean that circuit A communicates directly with circuit B (i.e., without an intermediary) or indirectly with circuit B (e.g., through one or more intermediaries).

[0099] References to the location of elements herein (e.g., “top,” “bottom,” “above,” “below”) are used only to describe the orientation of the various elements in the accompanying drawings. It should be noted that the orientation of the various elements may differ according to other exemplary embodiments, and such variations are intended to be included in this disclosure.

[0100] Despite Figure 6Various circuits with specific functions are illustrated herein; however, it should be understood that controller 140 may include any number of circuits for performing the functions described herein. For example, the activities and functions of offset circuit 220, gain circuit 222, compensation circuit 224, priority circuit 226, and actuator circuit 228 may be combined in multiple circuits or as a single circuit. Additional circuits with additional functions may also be included. Furthermore, controller 140 may further control other activities beyond the scope of this disclosure.

[0101] As described above, and in one configuration, the "circuit" can be implemented in a machine-readable medium for use by, for example Figure 6 The processor 204 executes on various types of processors. For example, executable code may include one or more physical or logical blocks of computer instructions, which may be organized, for example, into objects, procedures, or functions. However, executable files do not need to be physically located together, but may include different instructions stored in different locations that, when logically connected together, constitute a circuit and achieve the circuit's stated purpose. In practice, the circuit of computer-readable program code may be a single instruction or multiple instructions, and may even be distributed across several different code segments, between different programs, and across several memory devices. Similarly, operational data may be identified and represented herein in a circuit, and may be embodied in any suitable form and organized in any suitable type of data structure. Operational data may be collected as a single data set, or may be distributed across different locations, including different storage devices, and may exist at least partially, solely as electronic signals on a system or network.

[0102] While the term "processor" has been briefly defined above, the terms "processor" and "processing circuitry" should be interpreted broadly. In this regard, and as stated above, a "processor" can be implemented as one or more processors, application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), digital signal processors (DSPs), or other suitable electronic data processing components configured to execute instructions provided by memory. One or more processors can take the form of a single-core processor, a multi-core processor (e.g., a dual-core processor, a triple-core processor, a quad-core processor, etc.), a microprocessor, etc. In some embodiments, one or more processors can be external to the device; for example, one or more processors can be remote processors (e.g., cloud-based processors). Alternatively or additionally, one or more processors can be internal to the device and / or local. In this regard, a given circuitry or its components can be arranged locally (e.g., as part of a local server, a local computing system, etc.) or remotely (e.g., as part of a remote server such as a cloud-based server). For this purpose, a "circuitry" as described herein can include components distributed in one or more locations.

[0103] Although the accompanying drawings and specifications may show a specific order of method steps, this order may differ from that depicted and described unless otherwise specified above. Furthermore, two or more steps may be performed simultaneously or partially simultaneously unless otherwise specified above. For example, such variations may depend on the chosen software and hardware system and the designer's choices. All these variations are within the scope of this disclosure. Similarly, the software implementation of the described method can be accomplished using standard programming techniques with rule-based logic and other logic to perform various connection steps, processing steps, comparison steps, and decision steps.

Claims

1. A system for diagnosing an exhaust aftertreatment system and mitigating the effects of potential faults in the exhaust aftertreatment system, the system comprising: Sensors, which are configured to provide information on the composition of exhaust gases; and One or more processing circuits, comprising one or more memory devices coupled to one or more processors, said one or more memory devices being configured to store instructions thereon, which, when executed by said one or more processors, cause said one or more processors to: - Receive information indicating an amount that affects at least one of the gain or offset of the sensor; - Determine the compensation gain value and the compensation offset value based on the amount of at least one of the gain or the offset; - Receive the exhaust gas composition information from the sensor; - When the compensation gain value is less than a first threshold, the compensation offset value is less than a second threshold, and the compensation gain value is less than the compensation offset value, the compensation gain value is applied to the exhaust gas composition information to create compensated information; and - Initiate an action based on the compensated information.

2. The system according to claim 1, wherein, The sensor is a NOx sensor.

3. The system according to claim 2, wherein, The NOx sensor is either an engine output NOx sensor or a system output NOx sensor.

4. The system according to claim 1, wherein, The one or more memory devices are further configured to store instructions thereon that, when executed by the one or more processors, cause the one or more processors to: The low conversion efficiency of the selective catalytic reduction (SCR) system was determined based on the compensated information. and In response to determining that the conversion inefficiency of the SCR system exceeds a threshold, a fault indicator for the SCR system is triggered.

5. The system according to claim 1, wherein, The one or more memory devices are further configured to store instructions thereon that, when executed by the one or more processors, cause the one or more processors to: The low conversion efficiency of the selective catalytic reduction (SCR) system was determined based on the compensated information. and In response to determining that the conversion inefficiency of the SCR system exceeds a threshold, the reducing agent feeder of the SCR system is commanded to increase at least one of the feeding frequency or the feeding amount.

6. The system according to claim 1, wherein, The one or more memory devices are further configured to store instructions thereon that, when executed by the one or more processors, cause the one or more processors to: When the compensation gain value is greater than the first threshold, the compensation offset value is greater than the second threshold, and the compensation offset value is greater than the compensation gain value, the compensation offset value is applied to the exhaust gas composition information to create the compensated information.

7. The system according to claim 1, wherein, The one or more memory devices are further configured to store instructions thereon that, when executed by the one or more processors, cause the one or more processors to: When the compensation gain value is less than the first threshold, the compensation offset value is less than the second threshold, and the compensation offset value is less than the compensation gain value, the compensation offset value is applied to the exhaust gas composition information to create the compensated information.

8. The system according to claim 1, wherein, The gain includes high gain and low gain, and The one or more memory devices are further configured to store instructions thereon that, when executed by the one or more processors, cause the one or more processors to: The high gain was determined using an exponentially weighted moving average filter; and The low gain was determined using an exponentially weighted moving average filter.

9. The system according to claim 8, wherein, The one or more memory devices are further configured to store instructions thereon that, when executed by the one or more processors, cause the one or more processors to: Use at least one of the low gain or the high gain to query the dataset; and The compensation value is determined based on the information returned by the dataset.

10. The system according to claim 1, wherein, The offset includes high offset and low offset, and The one or more memory devices are further configured to store instructions thereon that, when executed by the one or more processors, cause the one or more processors to: The high offset was determined using an exponentially weighted moving average filter; and The low offset was determined using an exponentially weighted moving average filter.

11. A method for diagnosing an exhaust aftertreatment system and mitigating the effects of potential faults in the exhaust aftertreatment system, the method comprising: The controller receives data indicating the amount that affects at least one of the gain or offset of the sensors associated with the exhaust aftertreatment system; The controller determines the compensation gain value and the compensation offset value based on the amount of at least one of the gain or the offset; The controller receives data indicating the amount of exhaust gas components in the aftertreatment system; When the compensation gain value is less than a first threshold, the compensation offset value is less than a second threshold, and the compensation gain value is less than the compensation offset value, the controller applies the compensation gain value to data indicating the amount of the exhaust gas component in the aftertreatment system to create compensated data. and The controller initiates an action based on the compensated data.

12. The method according to claim 11, wherein, The sensor is a NOx sensor.

13. The method according to claim 12, wherein, The NOx sensor is either an engine output NOx sensor or a system output NOx sensor.

14. The method according to claim 11, wherein, Initiating the aforementioned action also includes: The controller determines the low conversion efficiency of the selective catalytic reduction (SCR) system of the aftertreatment system based on the compensated data; and In response to determining that the conversion inefficiency of the SCR system exceeds a threshold, the controller provides a fault indicator for the SCR system.

15. The method according to claim 11, wherein, Initiating the aforementioned action also includes: The controller determines the low conversion efficiency of the selective catalytic reduction (SCR) system of the aftertreatment system based on the compensated data; and In response to determining that the conversion inefficiency of the SCR system exceeds a threshold, the controller commands the reducing agent feeder of the post-processing system to increase at least one of the feeding frequency or the feeding amount.

16. The method of claim 11, further comprising: When the compensation gain value is greater than the first threshold, the compensation offset value is greater than the second threshold, and the compensation offset value is greater than the compensation gain value, the controller applies the compensation offset value to the data indicating the amount of NOx in the post-processing system to create the compensated data.

17. The method of claim 11, further comprising: When the compensation gain value is less than the first threshold, the compensation offset value is less than the second threshold, and the compensation gain value is less than the offset value, the controller applies the compensation gain value to data indicating the amount of exhaust gas components in the aftertreatment system to create the compensated data. and When the compensation gain value is less than the first threshold, the compensation offset value is less than the second threshold, and the compensation offset value is less than the compensation gain value, the controller applies the compensation offset value to the data indicating the amount of NOx in the post-processing system to create the compensated data.

18. A system for diagnosing an exhaust aftertreatment system and mitigating the effects of potential faults in the exhaust aftertreatment system, the system comprising: Selective catalytic reduction (SCR) system; Sensors are configured to provide information about the composition of exhaust gases; and The controller is configured as follows: - Receive the exhaust gas composition information from the sensor; - Determine the compensation gain value and compensation offset value; - When the compensation gain value is less than a first threshold, the compensation offset value is less than a second threshold, and the compensation gain value is less than the compensation offset value, the compensation offset value is applied to the exhaust gas composition information to create compensated information; and - Initiate an action based on the compensated information.

19. The system according to claim 18, wherein, The controller is also configured to: Based on the compensated information, the conversion inefficiency of the SCR system is determined; and In response to determining that the conversion inefficiency of the SCR system exceeds a threshold, the reducing agent feeder of the SCR system is commanded to increase at least one of the feeding frequency or the feeding amount.

20. The system according to claim 18, wherein, The controller is also configured to: When the compensation gain value is less than the first threshold, the compensation offset value is less than the second threshold, and the compensation offset value is less than the compensation gain value, the compensation offset value is applied to the exhaust gas composition information to create the compensated information; When the compensation gain value is greater than the first threshold, the compensation offset value is greater than the second threshold, and the compensation gain value is greater than the compensation offset value, the compensation gain value is applied to the exhaust gas composition information to create the compensated information; and When the compensation gain value is less than the first threshold, the compensation offset value is less than the second threshold, and the compensation gain value is less than the compensation offset value, the compensation gain value is applied to the exhaust gas composition information to create the compensated information.

Images