Systems and methods for sensor tamper detection

Abstract

A system, method, and apparatus for sensor tamper detection are provided. A post-processing system includes a first leg including a first selective catalytic reduction (SCR) system, a first doser, and a first NOx sensor, a second leg including a second SCR system, a second doser, and a second NOx sensor, and a controller. The controller determines satisfaction of an enable condition. The controller doses reductant to the first SCR system and the second SCR system. The controller determines NOx values of the first SCR system and the second SCR system. The controller adjusts the dosing to the first SCR system over a period of time. The controller measures the NOx values of the first SCR system and the second SCR system. The controller determines a difference between a third NOx value and a first NOx value and a difference between a fourth NOx value and a second NOx value. The controller generates an indication as to whether the first NOx sensor is shifted.

Description

[0001] Cross-referencing of related patent applications

[0002] This application claims priority and benefit to U.S. Patent Application No. 18 / 145,649, filed December 22, 2022, the entire disclosure of which is incorporated herein by reference. Technical Field

[0003] This application generally relates to a post-processing system, and more particularly to a system for detecting sensor tampering in a post-processing system. background

[0004] Emissions from internal combustion engines, such as diesel engines, include nitrogen oxides (NOx). x The goal is to reduce NO emissions. x Emissions, for example, to comply with environmental regulations. To reduce NO... x In the exhaust system, the reducing agent can be dispensed into the exhaust gas via a dosing system within the aftertreatment system. The reducing agent works in conjunction with the catalyst in the catalytic converter components to promote the conversion of a portion of the exhaust gas into non-NOx substances. x Emissions such as nitrogen (N2), carbon dioxide (CO2), and water (H2O) reduce NO. x Emissions. In some applications, these compounds in the exhaust can also be filtered or removed by one or more catalytic converter components located in the aftertreatment system, such as diesel oxidation catalyst (DOC) components, selective catalytic reduction (SCR) catalyst components, diesel particulate filter (DPF) components, ammonia oxidation (AMOx) catalyst components, etc.

[0005] Overview

[0006] Some aftertreatment systems may include multiple legs for reducing exhaust byproducts in the exhaust gases produced from an internal combustion engine. Each leg within the aftertreatment system has one or more components for reducing exhaust byproducts, such as catalytic converter components (e.g., SCR catalytic converter components, DOC components, etc.) and filters (e.g., DPF components). Each leg may include various sensors, such as those configured to sense NO at various locations within the aftertreatment system. x NO x Sensors. For example, NO located downstream of the SCR catalyst components. x The sensor is used to measure NO downstream of the SCR catalyst assembly (or SCR system). x Values ​​(e.g., NO) x (Quantity). NO x The value can be used to adjust or calibrate the dosage of reducing agent in the SCR system.

[0007] However, some users can tamper with the aftertreatment system by, for example, moving a sensor from one leg to another leg x Such sensor tampering can be challenging to detect during operation of the aftertreatment system (e.g., outside of repair or maintenance), potentially leading to inaccurate dosing of reductant and / or NOx x slip at the tailpipe. The systems, methods, and apparatus described herein allow for detection of sensor tampering, such as shifting / misplacement of a sensor (e.g., a NOx x sensor). The systems and methods of the technical solution are configured to override the ratio of ammonia to NOx x (e.g., the amount of ammonia relative to the amount of NOx x ) to identify whether the sensor is measuring data as expected based on changes (or lack of changes) in the NOx x measurement. Thus, by detecting the shifting of the sensor within the aftertreatment system, the systems and methods can notify an operator to perform maintenance or access a service center on the aftertreatment system such that potential NOx x slip can be minimized and such that the aftertreatment system can be made to comply with environmental regulations.

[0008] In some embodiments, an aftertreatment system includes a first branch including a first selective catalytic reduction (SCR) system and a first doser. The aftertreatment system includes a second branch including a second SCR system and a second doser. The aftertreatment system includes a controller. The controller is configured to determine that one or more enabling conditions are satisfied. In response to the one or more enabling conditions being satisfied, the controller is configured to dose a reductant to the first SCR system using the first doser and to dose the reductant to the second SCR system using the second doser. The controller is configured to determine, in response to the dosing, a first NOx value of the first SCR system based on readings from a first NOx sensor associated with the first branch and a second NOx value of the second SCR system based on readings from a second NOx sensor associated with the second branch. The controller is configured to adjust the dosing to the first SCR system for a first time period in response to the first NOx value and the second NOx value reaching a first predetermined threshold. At an end of a second time period after the adjusting of the dosing to the first SCR system, the controller is configured to measure a third NOx value of the first SCR system based on readings from the first NOx sensor and a fourth NOx value of the second SCR system based on readings from the second NOx sensor. The controller is configured to determine a first difference between the third NOx value and the first NOx value. The controller is configured to determine a second difference between the fourth NOx value and the second NOx value. The controller is configured to generate an indication as to whether the second NOx sensor is shifted based on the first difference and the second difference.

[0009] In some embodiments, the controller is configured to determine that the first NOx sensor and the second NOx sensor are not shifted in response to the first difference being greater than a second predetermined threshold and the second difference being less than the second predetermined threshold. In some embodiments, the controller is configured to determine that the first NOx sensor and the second NOx sensor are not shifted in response to determining that a difference between the second difference and the first difference is greater than the second predetermined threshold.

[0010] In some embodiments, the controller is configured to determine that the second NOx sensor is shifted in response to determining that the first difference is greater than the second predetermined threshold and a difference between the second difference and the first difference is less than a third predetermined threshold. In some embodiments, the one or more enabling conditions are satisfied in response to a bed temperature of each of the first SCR system and the second SCR system being greater than a second predetermined threshold.

[0011] In some embodiments, the one or more enabling conditions are satisfied in response to an engine out NOx value of each of the first branch and the second branch being greater than a second predetermined threshold. In some embodiments, the first time period is based on a time required for the first NOx value to change by a predetermined percentage.

[0012] In some embodiments, after determining that the first difference is greater than a second predetermined threshold and the difference between the second difference and the first difference is less than a third predetermined threshold, the controller is further configured to adjust the feed of the first SCR system during a third time period, greater than the adjustment of the feed of the first SCR system during the first time period. At the end of a fourth time period following the adjustment of the feed of the first SCR system during the third time period, the controller is configured to measure a fifth NOx value of the first SCR system based on readings from the first NOx sensor, and to measure a sixth NOx value of the second SCR system based on readings from the second NOx sensor. The controller is configured to determine a third difference between the fifth NOx value and the first NOx value. The controller is configured to determine a fourth difference between the sixth NOx value and the second NOx value. The controller is configured to generate an indication of whether the second NOx sensor has been shifted based on the third and fourth differences.

[0013] In some embodiments, after determining that a first difference is greater than a second predetermined threshold and the difference between the second difference and the first difference is less than a third predetermined threshold, the controller is further configured to adjust the feed to the first SCR system within a third time period. After adjusting the feed to the first SCR system within the third time period, the controller is configured to measure a fifth NOx value of the first SCR system based on readings from the first NOx sensor, and to measure a sixth NOx value of the second SCR system based on readings from the second NOx sensor. The controller is configured to determine a third difference between the fifth NOx value and the first NOx value. The controller is configured to determine a fourth difference between the sixth NOx value and the second NOx value. The controller is configured to generate an indication of whether the second NOx sensor has been shifted based on the third and fourth differences.

[0014] In some embodiments, a method includes a controller determining that one or more enabling conditions are met. In response to meeting one or more enabling conditions, the method includes the controller dispensing a reductant to a first selective catalytic reduction (SCR) system in a first branch using a first dispenser and dispensing a reductant to a second SCR system in a second branch using a second dispenser. The method includes, in response to dispensing, the controller determining a first NOx value of the first SCR system based on readings from a first NOx sensor associated with the first branch, and determining a second NOx value of the second SCR system based on readings from a second NOx sensor associated with the second branch. The method includes, in response to the first NOx value and the second NOx value reaching a first predetermined threshold, the controller adjusting the dispensing to the first SCR system within a first time period. At the end of a second time period following the adjustment of the dispensing to the first SCR system, the method includes, the controller measuring a third NOx value of the first SCR system based on readings from the first NOx sensor, and measuring a fourth NOx value of the second SCR system based on readings from the second NOx sensor. The method includes the controller determining a first difference between the third NOx value and the first NOx value. The method includes determining a second difference between a fourth NOx value and a second NOx value by a controller. The method also includes generating an indication from the controller based on the first and second differences regarding whether a second NOx sensor has been shifted.

[0015] In some embodiments, the method includes: in response to a first difference being greater than a second predetermined threshold and a second difference being less than a second predetermined threshold, the controller determines that the first NOx sensor and the second NOx sensor have not been shifted. In some embodiments, the method includes: in response to determining that the difference between the second difference and the first difference is greater than a second predetermined threshold, the controller determines that the first NOx sensor and the second NOx sensor have not been shifted.

[0016] In some embodiments, the method includes: in response to determining that a first difference is greater than a second predetermined threshold and that the difference between the second difference and the first difference is less than a third predetermined threshold, the controller determines that a second NOx sensor is shifted. In some embodiments, one or more enabling conditions are met in response to the bed temperature of each of the first SCR system and the second SCR system being greater than the second predetermined threshold.

[0017] In some embodiments, one or more enabling conditions are met in response to the engine output NOx value in each of the first and second branches exceeding a second predetermined threshold. In some embodiments, the first time period is the time required for a predetermined percentage to change based on the first NOx value.

[0018] In some embodiments, a controller includes one or more processors. The controller includes one or more memory devices coupled to one or more processors, the memory devices storing instructions that, when executed by one or more processors, cause one or more processors to: determine that one or more enable conditions are met; in response to the meeting of one or more enable conditions, dispense reductant to a first selective catalytic reduction (SCR) system in a first branch using a first dispenser and dispense reductant to a second SCR system in a second branch using a second dispenser; in response to dispensing, determine a first NOx value of the first SCR system based on readings from a first NOx sensor associated with the first branch, and a second NOx value based on readings from a second NOx sensor associated with the second branch. The readings of the x-sensor are used to determine a second NOx value for the second SCR system; in response to the first and second NOx values ​​reaching a first predetermined threshold, the feed rate to the first SCR system is adjusted within a first time period; at the end of a second time period after the feed rate adjustment to the first SCR system, a third NOx value of the first SCR system is measured based on the readings from the first NOx sensor, and a fourth NOx value of the second SCR system is measured based on the readings from the second NOx sensor; a first difference between the third NOx value and the first NOx value is determined; a second difference between the fourth NOx value and the second NOx value is determined; and an indication of whether the second NOx sensor has been shifted is generated based on the first and second differences.

[0019] In some embodiments, when executed by one or more processors, the instruction causes one or more processors to determine that the first NOx sensor and the second NOx sensor have not been shifted in response to a first difference being greater than a second predetermined threshold and a second difference being less than a second predetermined threshold. In some embodiments, when executed by one or more processors, the instruction causes one or more processors to determine that the first NOx sensor and the second NOx sensor have not been shifted in response to determining that the difference between the second difference and the first difference is greater than a second predetermined threshold.

[0020] In some embodiments, when executed by one or more processors, the instruction causes one or more processors to determine that the second NOx sensor has been shifted in response to determining that a first difference is greater than a second predetermined threshold and that the difference between the second difference and the first difference is less than a third predetermined threshold.

[0021] In some embodiments, one or more enabling conditions are met in response to the bed temperature of each of the first SCR system and the second SCR system exceeding a second predetermined threshold. In some embodiments, one or more enabling conditions are met in response to the engine output NOx value of each of the first branch and the second branch exceeding a second predetermined threshold. Brief description of the attached diagram

[0022] Details of one or more embodiments are set forth in the accompanying drawings and the following description. Other features, aspects, and advantages of this disclosure will become apparent from the specification, drawings, and claims, wherein:

[0023] Figure 1 This is an example schematic diagram of an engine exhaust aftertreatment system coupled to a controller;

[0024] Figure 2 It is by Figure 1 An example flowchart outlining the diagnostic process performed by the controller;

[0025] Figure 3 It is shown in Figure 1 Ammonia and NO in the after-treatment system x Example graphs showing the behavior of a healthy after-treatment system during over-control of the ANR (Advanced Processing Ratio);

[0026] Figure 4 It is shown in Figure 1 Example graphs showing the behavior of a post-processing system with tampered sensors during ANR overrun in the post-processing system.

[0027] Figure 5 It is shown in Figure 1 Use NO x Example graphs showing the behavior of a healthy post-processing system during ANR overrun in a post-processing system;

[0028] Figure 6 It is shown in Figure 1 Use NO x Example graphs showing the behavior of a post-processing system with tampered sensors during ANR overrun in the value post-processing system.

[0029] Figure 7 It is used for detection Figure 1 A flowchart illustrating an example process for methods of sensor tampering in a post-processing system;

[0030] Figure 8 It is used for execution Figure 7 Example process flowchart of a method for detecting sensor tampering;

[0031] Figure 9 Is to show execution Figure 7 and Figure 8 Example curves of the first diagnostic results using the method;

[0032] Figure 10 Is to show execution Figure 7 and Figure 8 Example curves of the second diagnostic case using the method;

[0033] Figure 11 Is to show execution Figure 7 and Figure 8 Example curves of the third diagnostic case using the method; and

[0034] Figure 12 Is to show execution Figure 7 and Figure 8 Another example curve for the fourth diagnostic case of the method.

[0035] It will be appreciated that some or all of the drawings are illustrative representations for purposes of explanation. The drawings are provided to illustrate one or more embodiments and are expressly understood not to be used to limit the scope or meaning of the claims. Detailed description

[0036] The following is a more detailed description of various concepts related to methods, apparatuses, and systems for detecting sensor tampering within a post-processing system, as well as embodiments of these methods, apparatuses, and systems. The various concepts introduced above and discussed in more detail below can be implemented in any of a variety of ways, as the described concepts are not limited to any particular implementation. Examples of specific embodiments and applications are provided primarily for illustrative purposes.

[0037] I. Overview

[0038] Internal combustion engines (e.g., diesel engines, etc.) produce exhaust gases (sometimes referred to as waste gases). Depending on the fuel consumed by the internal combustion engine, the exhaust gases can contain various byproducts (e.g., NO). x Exhaust gases include carbon monoxide (CO), unburned hydrocarbons (HC), etc. Byproducts in the exhaust can be measured or sensed by one or more sensors in the aftertreatment system, for example, measuring the exhaust density, volume, parts per million (ppm), etc. The aftertreatment system can be connected to the engine, for example, via the exhaust pipe from the engine. For simplicity, the examples in this document may provide NO. x As a byproduct of exhaust gas, and the sensor can be configured to sense NO downstream of the engine (e.g., anywhere along the exhaust pipe). x NO emissions x Sensor. Although the examples described include measuring NO. x NO by-products x The system described is a sensor, but it can be applied to other sensors.

[0039] Byproducts in exhaust gases can be reduced by one or more aftertreatment components in an engine system, including an aftertreatment system, such as a DOC component or an SCR catalyst component, and other types of catalysts. An aftertreatment system may include multiple branches. For simplicity, the examples herein provide an aftertreatment system comprising two branches; however, an aftertreatment system may include more than two branches with corresponding components for reducing exhaust byproducts. For example, exhaust gases may flow through or through the aftertreatment system via a first branch and a second branch. The catalyst component in each branch (e.g., an SCR catalyst component, a DOC component, etc.) can promote a chemical reaction between byproducts and a reducing agent to reduce or minimize emissions from the exhaust pipe of the engine system. For simplicity, the examples herein may provide an SCR catalyst component or a DOC component as the catalyst component of the aftertreatment system. Each branch of the aftertreatment system may be supplied with ammonia (NH3) (e.g., a reducing agent) to reduce exhaust byproducts. The amount of reducing agent supplied may be based on NO from the corresponding branch. x sensor NO x Measurement results (and / or other factors, such as exhaust gas mass flow rate).

[0040] However, some users may tamper with the post-processing system, for example, by changing the NO... x The sensor is moved from one branch to another, for example, to attempt to potentially alter (e.g., reduce) the amount of reductant dispensed during aftertreatment system operation. In these cases, detecting sensor tampering during aftertreatment system operation can be challenging because sensor readings are still being captured, potentially leading to inaccurate reductant dispensed amounts and / or NO at the tailpipe. x escape.

[0041] The systems, methods, and apparatus described herein are configured to detect tampering with post-processing systems, such as sensors (e.g., NO). x Sensor tampering / misalignment. The terms sensor tampering, sensor displacement, sensor misalignment, or similar terms are used interchangeably herein and indicate the removal of NO from a branch. xThe sensor is (e.g., completely removed or moved to another branch). In various embodiments, the system and method of the technical solution include a controller (e.g., a computing device or data processing system) configured to perform the features or functions discussed herein for sensor tampering detection. The controller includes at least one processor coupled to at least one memory. For example, the controller determines that one or more enable conditions are met. In response to the satisfaction of one or more enable conditions, the controller dispenses a reducing agent to a first SCR system using a first dispenser and dispenses a reducing agent to a second SCR system using a second dispenser. In response to dispensing, the controller determines a first NOx value of the first SCR system based on readings from a first NOx sensor and a second NOx value of the second SCR system based on readings from a second NOx sensor. In response to the first NOx value and the second NOx value reaching a first predetermined threshold, the controller stops dispensing to the first SCR system for a first time period. At the end of a second time period after stopping dispensing to the first SCR system, the controller measures a third NOx value of the first SCR system based on readings from the first NOx sensor and a fourth NOx value of the second SCR system based on readings from the second NOx sensor. The controller determines a first difference between the third NOx value and the first NOx value. The controller determines a second difference between the fourth NOx value and the second NOx value. Based on the first and second differences, the controller generates an indication as to whether the first NOx sensor has been shifted.

[0042] These features enable the embodiments described herein to detect NO in the post-processing system. x Sensor tampering allows operators and / or maintenance technicians to be notified to resolve sensor misalignment. Therefore, the embodiments described herein can reduce NO downstream of the SCR system caused by system tampering. x It allows for escape and complies with environmental regulations regarding the aftertreatment system.

[0043] II. Overview of Sensor Tampering Detection

[0044] Referring generally to the accompanying drawings, the various embodiments disclosed herein relate to systems, apparatus, and methods for detecting sensor tampering. The post-treatment system reduces byproducts (e.g., NO) in exhaust gases. x Components containing (such as) soot and carbon dioxide include SCR systems, which use a two-step process to reduce harmful NOx in exhaust or DOC components. xEmissions are filtered or oxidized by the SCR (Self-Reducing Catalytic Reduction) system, which filters or oxidizes hydrocarbons, carbon monoxide, or unburned fuels and oils. First, referring to the SCR, the dispenser injects a reducing agent into the exhaust stream. This reducing agent can be urea, diesel exhaust fluid (DEF), Adblue®, urea solution (UWS), aqueous urea solution (e.g., AUS32), or another similar fluid. The reducing agent may decompose into NH3 after injection. This mixture then passes through the SCR catalytic converter components, which, at a certain temperature, initiate a reaction in the mixture, releasing harmful NO3-. x The particles are converted into pure nitrogen and water. During operation, undecomposed reducing agent and unreacted ammonia can be stored within the catalytic converter components (e.g., SCR catalytic converter components) to react with exhaust products (e.g., NO). x Chemical reactions occur between particles, etc.

[0045] NO x The sensor can be used to measure NO in exhaust byproducts at various locations / positions within the aftertreatment system. x The amount (e.g., NO) x Value). At least one NO x The sensor can be positioned upstream of the SCR system (e.g., at or before the SCR system inlet) to measure NO entering the SCR system. x The amount. At least one NO. x The sensor can be positioned downstream of the SCR system (e.g., at or after the SCR system outlet) to measure NO remaining in or escaping through the SCR system. x The amount (e.g., not converted into pure nitrogen and water). Measured NO x The value can be used to adjust the reducing agent dosage to improve the conversion efficiency of the SCR system (e.g., upstream NO). x Value and downstream NO x (The difference between values). However, in a tampered system, where NO... x The sensor is misaligned or shifted from one branch to another, for those without NO x The reducing agent dosage in the sensor's branch may be inaccurate. For simplicity and the examples discussed herein, it can be assumed that the tampering targets the NO downstream of the SCR system in one of the branches. x Sensors. For example, tampering could involve modifying the NO sensor located downstream of the corresponding SCR system. x The sensor is moved from the first branch to the second branch, or vice versa.

[0046] Therefore, in order to minimize the potential NO of the SCR system xTo escape and remain compliant with environmental regulations, the systems and methods discussed herein can perform operations to detect sensor tampering in post-processing systems. For example, the systems and methods can perform ANR overshoot control to monitor sensor measurements (e.g., NO) in response to changes in the reductant dosage. x The characteristics of the sensor measurement results enable the detection of NO. x Sensors (e.g., the first NO expected to be located in their respective branches) x Sensor and second NO x Whether the sensors are located in their respective branches or, alternatively, in the same branch of the post-processing system.

[0047] Now for reference Figure 1 A schematic diagram of a system 10 with a controller 100 according to an example embodiment is shown. System 10 includes an internal combustion engine 20 (hereinafter referred to as an "engine") coupled to an exhaust aftertreatment system 22, which is in exhaust gas receiving communication with the engine. As shown, the exhaust aftertreatment system 22 consists of multiple branches (e.g., a first branch 22A and a second branch 22B), each branch including one or more corresponding components of the exhaust aftertreatment system 22. Although two branches are shown and described for illustrative purposes herein, the exhaust aftertreatment system 22 may include more than two branches consisting of additional components of the exhaust aftertreatment system 22. The controller 100 is coupled to or communicates with system 10 and operator input / output (I / O) devices 120. System 10 may be embodied in a vehicle. The means of transport can be an on-road vehicle or an off-road vehicle, including but not limited to long-haul trucks, mid-range trucks (e.g., pickup trucks), automobiles, ships, tanks, aircraft, locomotives, mining equipment, and any other type of means of transport. A means of transport may include a transmission, fuel system, one or more additional means of transport subsystems, etc. In this respect, a means of transport may include more, fewer, and / or different components / systems, such that the principles, methods, systems, apparatus, processes, etc., of this disclosure are intended to be applicable to any other means of transport configuration. It should also be understood that the principles of this disclosure should not be construed as limited to means of transport; rather, this disclosure also applies to several stationary pieces of equipment such as generators or generator sets.

[0048] Engine 20 may be a compression-ignition internal combustion engine utilizing diesel fuel. In various other embodiments, engine 20 may be configured as any other type of engine (e.g., spark-ignition) utilizing any type of fuel (e.g., gasoline, natural gas, etc.). In some embodiments, the vehicle may be another type of vehicle, such as a hybrid vehicle incorporating one or more electric motors, a fuel cell vehicle, etc. Therefore, although engine 20 is configured herein as a diesel-powered internal combustion engine, other embodiments are contemplated to fall within the scope of this disclosure.

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

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

[0051] The exhaust aftertreatment system 22 also includes an exhaust gas recirculation (EGR) system 70. The SCR systems 52A and 52B of the respective branches also include a reducing agent delivery system having reducing agent sources 54A-54B (e.g., reducing agent source 54 of the branch), which supply reducing agent to reducing agent dispensers 56A-56B (e.g., dispensers 56 commonly referred to as dispensers 56 for the first branch 22A and the second branch 22B) via reducing agent lines 58A-58B, respectively.

[0052] In the exhaust flow direction indicated by directional arrow 29, exhaust gas flows from engine 20 into inlet pipe 24 of exhaust aftertreatment system 22. In first branch 22A, exhaust gas flows from inlet pipe 24 into DOC component 30 and exits DOC component 30 into first section 28A of exhaust pipe. Exhaust gas flows from first section 28A of exhaust pipe into DPF component 40 and exits DPF component 40 into second section 28B of exhaust pipe. Exhaust gas flows from second section 28B of exhaust pipe into SCR catalytic converter component 50 and exits SCR catalytic converter component 50 into third section 28C of exhaust pipe. As exhaust gas flows through second section 28B of exhaust pipe, reductant is periodically supplied to it via reductant dispenser 56. Therefore, second section 28B of exhaust pipe acts as a decomposition chamber or pipe to facilitate the decomposition of reductant into ammonia. Exhaust gas flows from third section 28C of exhaust pipe into AMOx catalytic converter component 60 and exits AMOx catalytic converter component 60 into outlet pipe 26 before being discharged from aftertreatment system 22. Similarly, in the second branch 22B, the exhaust gas flows through pipes 28D-28F, which pass through various components in the second branch 22B and enter the outlet pipe 26.

[0053] Based on the foregoing, in the illustrated embodiment, DOC component 30 (e.g., DOC component 30A or DOC component 30B) is positioned upstream of DPF component 40 (e.g., DPF component 40A or DPF component 40B) and SCR catalyst component 50 (e.g., SCR catalyst component 50A or SCR catalyst component 50B), and SCR catalyst component 50 (e.g., SCR catalyst component 50A or SCR catalyst component 50B) is positioned downstream of DPF component 40 (e.g., DPF component 40A or DPF component 40B) and upstream of AMOx catalyst component 60 (e.g., AMOx catalyst component 60A or AMOx catalyst component 60B). However, in alternative embodiments, other arrangements of the components of the exhaust aftertreatment system 22 are also possible. Furthermore, and for simplicity, the components of one branch of the exhaust aftertreatment system 22 can resemble those of another branch. Alternatively, the arrangement of one or more components or parts in the first branch 22A may differ from that in the second branch 22B, and so on.

[0054] DOC component 30 can be configured with any number of different types of flow designs. DOC component 30 can be configured to oxidize at least some particulate matter in the exhaust gas (e.g., the soluble organic portion of soot) and reduce unburned hydrocarbons and CO in the exhaust gas into compounds less harmful to the environment. For example, DOC component 30 can be configured to reduce the concentration of hydrocarbons and CO in the exhaust gas to meet the necessary emission standards for those components. An indirect result of the oxidation capacity of DOC component 30 is its ability to oxidize NO to NO2. In this way, in addition to the NO2 converted from NO by DOC component 30, the level of NO2 leaving DOC component 30 is equal to the NO2 in the exhaust gas produced by engine 20.

[0055] In addition to treating hydrocarbon and CO concentrations in exhaust gas, the DOC component 30 can also be used for the controlled regeneration of the DPF component 40, SCR catalyst component 50, and AMOx catalyst component 60. This can be achieved by injecting or feeding unburned HC into the exhaust gas upstream of the DOC component 30. Upon contact with the DOC component 30, the unburned HC undergoes an exothermic oxidation reaction, resulting in an increase in exhaust gas temperature leaving the DOC component 30 and subsequently entering the DPF component 40, SCR catalyst component 50, and / or AMOx catalyst component 60. The amount of unburned HC added to the exhaust gas is selected to achieve the desired temperature increase or the target controlled regeneration temperature.

[0056] DPF component 40 can be any of various flow designs and is configured to reduce the concentration of particulate matter (e.g., soot and ash) in exhaust gas to meet necessary emission standards. DPF component 40 captures particulate matter and other components, and can therefore be periodically regenerated to burn off the captured components. Additionally, DPF component 40 can be configured to oxidize NO to form NO2 independently of DOC component 30.

[0057] As described above, the SCR system 52 includes a reductant delivery system. The reductant delivery system includes a reductant source 54, a pump (not shown), and a dispenser 56 (e.g., sometimes referred to as a delivery mechanism 56). The reductant source 54 may be a container or tank capable of holding the reductant. The reductant source 54 is in reductant supply communication with the pump, which is configured to pump the reductant from the reductant source 54 to the delivery mechanism 56 via a reductant delivery line 58. The delivery mechanism 56 is located upstream of the SCR catalyst assembly 50. The delivery mechanism 56 can be selectively controlled to inject the reductant directly into the exhaust stream before it enters the SCR catalyst assembly 50. As described herein, the controller 100 is configured, for example, based on NO from upstream of the SCR system 52. x NO measured by sensor 12 xThe amount and timing of the reducing agent delivered to the exhaust gas are controlled by the amount of [unspecified substance]. The reducing agent decomposes to generate ammonia. As briefly described above, ammonia reacts with NO in the presence of SCR catalyst component 50. x The reaction, to convert NO x It is reduced to less harmful emissions, such as N2 and H2O. NO in the exhaust stream x This includes NO2 and NO. In the presence of NH3, both NO2 and NO are reduced to N2 and H2O through various chemical reactions driven by the catalytic elements of the SCR catalyst component.

[0058] In some embodiments, the controller 100 is configured to control the delivery mechanism 56 according to the reaction of ammonia and NO. x The ratio (ANR) is used to supply the reducing agent. In NO x Content (e.g., NO output from the engine) x When the amount of reducing agent increases, the controller 100 can control the conveying mechanism 56 to increase (or maintain) the amount of reducing agent supplied, thereby conforming to / satisfying the ANR. Furthermore, in NO... x When the content decreases, controller 100 can control conveying mechanism 56 to reduce (or maintain) the reductant feed rate to meet ANR. Controller 100 is configured to over-control ANR to adjust the amount of reductant fed into the exhaust stream. Decreasing ANR corresponds to a decrease in the reductant feed rate, and increasing ANR corresponds to an increase in the reductant feed rate. For simplicity, and for the purposes of this example, NO associated with ANR is... x The amount can be measured at the engine outlet (e.g., at the NO outlet of engine 20). x (Sensor). In some other examples, the post-processing system 22 may include a NO located upstream of the DOC component 30 in the branch. x Sensor 12, and from these NO x NO from sensor 12 x The measurement results can be used to determine the ANR associated with the corresponding branch.

[0059] In some embodiments, the SCR catalyst component 50 is a vanadium-based catalyst component, and in other embodiments, the SCR catalyst component is a zeolite-based catalyst component, such as a copper zeolite (Cu-Ze) or iron zeolite (Fe-Zu) catalyst component. In one representative embodiment, the reducing agent is aqueous urea, and the SCR catalyst component 50 is a zeolite-based catalyst component. In other embodiments, the reducing agent includes a first reducing agent and a second reducing agent, wherein the first reducing agent is urea and the second reducing agent is ammonia.

[0060] The AMOx catalytic converter component 60 can be any of various flow-through catalytic converter components configured to react with ammonia to primarily produce nitrogen. As briefly described above, the AMOx catalytic converter component 60 is configured to remove ammonia that has escaped or left the SCR catalytic converter component 50 without reacting with NOx in the exhaust gas. In some cases, the aftertreatment system 22 can operate with or without the AMOx catalytic converter component. Furthermore, although the AMOx catalytic converter component 60... Figure 1 The AMOx catalyst component is shown as a separate unit from the SCR system 52, but in some embodiments, the AMOx catalyst component may be integrated with the SCR catalyst component (e.g., the AMOx catalyst component and the SCR catalyst component may be located within the same housing). As described herein, the SCR catalyst component 50 and the AMOx catalyst component 60 form the SCR and AMOx systems.

[0061] System 10 (e.g., post-processing system 22) includes various sensors. For example, post-processing system 22 includes NO... x Sensor 12. The aftertreatment system 22 includes a temperature sensor 14. The aftertreatment system 22 includes a pressure sensor 16. Sensors can be strategically positioned throughout the aftertreatment system 22, such as upstream, downstream, or at one or more catalysts (e.g., DOC component 30, DPF component 40, SCR catalyst component 50, and / or AMOx catalyst component 60). Sensors can communicate with controller 100 and are configured to monitor the operating conditions of system 10. It should be understood that one or more NO... x Sensors, pressure sensors, temperature sensors, and various other sensors (oxygen sensors, exhaust composition sensors, NH3 sensors) can also be included in the system and set in various locations.

[0062] As shown in the figure, NO x Sensor 12 can be located upstream and downstream of a catalyst assembly, including SCR catalyst assembly 50 or AMOx catalyst assembly 60. In this configuration, NO x Sensor 12 can at least measure NO entering the SCR system 52 x The amount of NO remaining in the exhaust gas or not converted by the SCR system 52 x (For example, NO escaping through SCR catalyst component 50) x The amount of NO upstream and downstream of SCR catalyst component 50. x The difference between the quantities represents or corresponds to the conversion efficiency of the corresponding branch. For example, the NO upstream and downstream of SCR catalyst component 50A x The difference between the quantities corresponds to the conversion efficiency of the first branch 22A. The upstream and downstream NO of the SCR catalyst component 50B... xThe difference between the quantities corresponds to the conversion efficiency of the second branch 22B. For simplicity, and for the purposes of this example, the flow distribution (mass flow rate) of the exhaust gas through the first branch 22A and the second branch 22B and the NO... x The content can be similar across these branches. Therefore, for simplicity and for the purposes of this example, the relatively high NO content measured downstream of SCR catalyst component 50 is used. x The content / amount corresponds to a relatively low conversion efficiency and a relatively low NO content measured downstream of the SCR catalyst component 50. x The content corresponds to a relatively high conversion efficiency in the corresponding branch.

[0063] In some configurations, a NO x Sensor 12 measures the NO output of the engine. x And another NO x Sensor 12 measures NO at the inlet of the SCR catalyst component 50. x This is due to the potential oxidation of NO output by DOC component 30 / DPF component 40. x A portion of this will result in the engine's NOx output not being equal to the inlet NO of the SCR catalyst component 50. x Quantity. Therefore, this configuration takes into account this potential difference. NO leaving the SCR catalyst component 50 x The amount can be generated by NO located downstream of SCR catalyst component 50. x Sensor 12 and / or NO located downstream of AMOx catalyst component 60 x Sensor 12 measures. NO. x Sensor 12 (in some embodiments, NO) x Sensor 12) is located downstream of the SCR catalyst assembly 50 and is configured to detect NO in exhaust gas downstream of the SCR catalyst assembly (e.g., exiting the SCR catalyst assembly). x Concentration. From NO x The measurement results of sensor 12 (e.g., the measured NO) x The data is used by controller 100 to determine the NO of the corresponding branch across post-processing system 22. x Conversion efficiency. NO. x Conversion efficiency corresponds to a reduction in NO across one or more components of the post-processing system 22. x The amount. Although NO x Sensor 12 is shown at the outlet of engine 20, but the corresponding NO... x Sensor 12 can be located upstream of the corresponding DOC component 30 or DPF component 40 in each branch.

[0064] In some embodiments, NOx Sensor 12 can be moved from one branch to another, such as from the first branch 22A to the second branch 22B or from the second branch 22B to the first branch 22A. For simplicity and for the purposes of this example, NO is located downstream of the SCR catalyst assembly 50 (and / or the AMOx catalyst assembly 60). x Sensor 12 can move from one branch to another. In this configuration, multiple NO... x Sensor 12 is positioned at a relatively similar location, for at least one of the branches, the conversion efficiency (e.g., with respect to NO downstream of SCR catalyst component 50) x Content-related factors may be calculated or measured inaccurately. For example, if the first NO in the first branch 22A is... x The sensor was moved to the second branch 22B (the second NO adjacent to the second branch 22B). x (Sensor), then the conversion efficiency calculated for both branches may only be calculated relative to the second branch. Therefore, the first NO from the first branch 22A is expected to be... x Sensor and expected second NO in second branch 22B x The sensor's measurement data is provided to the controller 100 to determine whether the sensor has been misaligned / displaced.

[0065] Temperature sensor 14 is associated with one or more catalytic converter components. Temperature sensor 14 is strategically positioned to detect the temperature of exhaust gas flowing into DOC component 30 (e.g., the temperature of an exhaust pipe upstream of the catalytic converter component), the temperature of exhaust gas flowing out of DOC component 30 (e.g., the temperature of an exhaust pipe downstream of the catalytic converter component) and into another catalytic converter component (e.g., from DOC component 30 to DPF component 40), and the temperature of exhaust gas flowing out of DPF component 40 before being dispensed with reducing agent via dispenser 56. In some embodiments, at least one temperature sensor 14 may be configured as part of the catalytic converter component itself, thereby directly measuring the bed temperature of the catalytic converter component.

[0066] EGR system 70 is configured to recirculate exhaust gas back to the intake manifold of engine 20 for combustion. EGR system 70 includes an EGR cooler 74 and an EGR valve 76. In some applications, EGR cooler 74 may be, for example, an air-to-air and / or liquid (e.g., coolant)-to-air (e.g., exhaust gas) heat exchanger. EGR cooler 74 is configured to remove heat from the exhaust gas before it is reintroduced into the intake manifold. Heat is removed from the exhaust gas before reintroduction, among other reasons, to prevent high intake air temperatures that could promote pre-ignition (e.g., engine knock).

[0067] Although the exhaust aftertreatment system 22 shown includes a DOC component 30, a DPF component 40, an SCR catalyst component 50, and an AMOx catalyst component 60 positioned relative to each other along the exhaust flow path, in other embodiments, the exhaust aftertreatment system may include more than one of the DOC component 30, DPF component 40, SCR catalyst component 50, and AMOx catalyst component 60 positioned relative to each other along the exhaust flow path.

[0068] Figure 1 Also shown is an operator input / output (I / O) device 120. The operator I / O device 120 is communicatively coupled to the controller 100, enabling information exchange between the controller 100 and the I / O device 120. The information exchanged between the controller 100 and the I / O device 120 may involve... Figure 1 One or more components or any of the components of the controller 100 disclosed herein. The operator I / O device 120 enables the operator of the vehicle (e.g., a passenger, etc.) to communicate with the controller 100 and other components of the vehicle, such as in... Figure 1 The components shown are examples of those in the diagram. For instance, operator I / O device 120 may include an interactive display, a touchscreen device, one or more buttons and switches, a voice command receiver, etc. In some cases, I / O device 120 may be part of a vehicle that includes engine 20 and aftertreatment system 22. In other cases, I / O device 120 may be a remote device accessible to the operator, such as one accessed via a client device. In some aspects, I / O device 120 may be a server that receives data from the vehicle's controller 100.

[0069] Controller 100 is configured to monitor operations, conditions, or events within system 10 (e.g., components of aftertreatment system 22). Controller 100 is configured to at least partially control system 10 and associated subsystems (such as internal combustion engine 20 and exhaust aftertreatment system 22). Communication between and within components can be via 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. In contrast, wireless connections may include the Internet, Wi-Fi, cellular, radio, Bluetooth, etc. In one embodiment, a controller local 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 100 is communicatively coupled to… Figure 1 The system and components, so the controller 100 is configured to... Figure 1 One or more of the components shown receive data. For example, the data may include NO. xData (e.g., NO from DOC component 30 or SCR catalyst component 50) x Input NO of sensor 12 x The amount and NO from downstream of the SCR catalyst component 50 x The output NO of sensor 12 x The data includes quantity and distribution data (e.g., timing and quantity of distributions delivered from dispenser 56) and vehicle operation data received via one or more sensors (e.g., engine speed, vehicle speed, engine temperature, flow rate, etc.). As another example, the data may include input from operator input / output device 120. Using this data, as described more fully herein, controller 100 monitors multi-branch aftertreatment system 22 to determine NO. x Whether sensor 12 has been shifted from one branch to another (e.g., user tampering with at least one NO) x Sensor 12), and detects NO. x Misalignment of sensor 12 to minimize NO downstream of SCR system 52 due to incorrect calculation of conversion efficiency. x The escape of reducing agent or NO due to incorrect measurement of content x escape.

[0070] Controller 100 includes processing circuitry, which includes a processor, memory, and various circuits configured to perform the features, functions, or operations discussed herein. The processor may be implemented as an application-specific integrated circuit (ASIC), one or more field-programmable gate arrays (FPGAs), a digital signal processor (DSP), a set of processing units, or other suitable electronic processing units. The memory (e.g., RAM, ROM, flash memory, hard disk storage, etc.) may store data and / or computer code to facilitate the various processes described herein. The memory may be communicatively connected to the processor and one or more circuits. The memory is configured to provide the processor with computer code or instructions for performing the processes described with respect to controller 100 herein. Furthermore, the memory may be or include tangible, non-transient volatile memory or non-volatile memory. Therefore, the memory may include database components, object code components, scripting components, or any other type of information structure used to support the various activities and information structures described herein.

[0071] Controller 100 includes a communication interface. The communication interface 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 and within components of a vehicle) and out-of-vehicle communication (e.g., direct communication with a remote computing system). In this regard, in some embodiments, the communication interface includes a network interface. The network interface is used to establish connections with other computing devices via a network. The network interface includes program logic that facilitates controller 100's connection to a network. The network interface includes any combination of wireless network transceivers (e.g., cellular modems, Bluetooth transceivers, Wi-Fi transceivers) and / or wired network transceivers (e.g., Ethernet transceivers). In some arrangements, the network interface includes hardware and machine-readable media sufficient to support communication over multiple data communication channels. Furthermore, in some arrangements, the network interface includes encryption capabilities for establishing secure or relatively secure communication sessions, wherein data transmitted over the session is encrypted. For example, regarding communication outside the vehicle / system, the communication interface may include Ethernet cards and ports for sending and receiving data via an Ethernet-based communication network and / or Wi-Fi transceivers for communication via a wireless communication network. The communication interface may be configured to communicate via a local area network and / or a wide area network (e.g., the Internet) and may use various communication protocols (e.g., IP, LON, Bluetooth, ZigBee, and radio, cellular, and near-field communication). Furthermore, the communication interface may work in conjunction with or in series with a telematics unit (if included) to communicate with other vehicles and / or remote computing systems in the fleet.

[0072] The controller 100 is configured to receive input (e.g., signals, information, data, etc.) from components / systems of system 10 and / or operator I / O devices 120. Therefore, the controller 100 is configured to at least partially control the components / systems of system 10 and the associated engine 20. Because Figure 2 The components can be included in the vehicle, so the controller 100 can be configured as one or more electronic control units (ECUs). The controller 100 can be separate from or included with at least one of the following: a transmission control unit, an exhaust aftertreatment control unit, a powertrain control module, an engine control module, etc. In some cases, the controller 100 can be a device remote from the vehicle, such as a remote controller configured as one or more components of the control system 10 or communicating with such one or more components.

[0073] refer to Figure 2It depicts the Figure 1 Example flowchart of the diagnostic process 200 performed by controller 100. Figure 2 The steps can be performed by System 10, a data processing system, a cloud computing environment, or in combination with the methods described in this article. Figure 1 The process 200 may be performed by any other components of the computing device described (e.g., controller 100, I / O device 120, post-processing system 22, sensors, etc.). For example, additional or alternative operations of process 200 may be performed by one or more circuits of controller 100. Additionally or alternatively, some operations of process 200 may be performed by a remote device (such as a remote data processing system). Some steps of process 200 may involve controller 100 receiving data from components of post-processing system 22 (such as one or more sensors) and forwarding the data to a remote device for processing, or vice versa. Process 200 may include combinations of... Figure 8 An overview of the described process.

[0074] In step 202, controller 100 determines whether one or more enabling conditions are met. Enabling conditions may include at least one of the following: engine output NO. x To meet the desired target value / threshold, the bed temperature of the SCR catalyst component 50 must be at or above the lower limit / threshold, the rate of change of the bed temperature must be at or above the upper limit / threshold, or the time gap between multiple attempts must meet a time threshold, or other predefined conditions. Engine output NO. x Corresponding to NO located downstream of engine 20 or at the outlet of engine 20. x NO measured by sensor 12 x The quantity. These attempts refer to performing the operations discussed in this article to detect at least one sensor (e.g., NO). x (Identify whether the sensor is misaligned.) In response to determining that one or more enable conditions are met, controller 100 proceeds to step 204.

[0075] In step 204, controller 100 is configured to determine whether the conversion efficiency (CE) of a branch (e.g., first branch 22A and second branch 22B) is stable. For example, controller 100 calculates the standard deviation of the CE for each branch over a predetermined duration (e.g., 1 minute, 2 minutes, 3 minutes, etc.). Controller 100 compares the calculated standard deviation to a threshold (e.g., 2%, 4%, 2% to 5%, etc.). If the standard deviations of both branches are within the threshold, controller 100 determines that the CE of the branch is stable. In response to this determination, controller 100 filters (sometimes referred to as filtered stable CE) the stable CEs monitored during that duration. A stable CE is defined as a CE value monitored within the standard deviation threshold during the duration. Controller 100 stores the filtered stable CEs in a local memory device or storage unit. In some cases, controller 100 stores the filtered stable CEs in a remote data repository. The stored CEs can be at least one of a dataset of CEs calculated or monitored during the duration, aggregated CE values ​​(e.g., average or mean), a range of CE values, etc. Although CE was measured and analyzed in these examples, it can be used with various NOs. x NO measured by sensor 12 x Values ​​are used to perform similar analyses.

[0076] In step 206, controller 100 is configured to apply (intrusive) ANR overshoot to one branch of the post-processing system 22. Intrusive ANR overshoot can refer to reducing the ANR value below a predetermined threshold (e.g., below 0.9 ANR) or increasing the ANR value above a predetermined threshold (e.g., above 1.5 ANR), thereby enabling NO... x Detectable features in sensor readings include, for example, depletion of reductant stores (using a relatively low ANR) or reductant escape (using a relatively high ANR). In some embodiments, invasive ANR overshooting may refer to increasing or decreasing the ANR value to a certain ANR range, such as a low ANR range (e.g., 0.1 ANR to 0.9 ANR) or a high ANR range (e.g., 1.5 ANR to 3 ANR). In some embodiments, an ANR range of 1.1–1.3 may be targeted (e.g., at SCR bed temperatures greater than 300 degrees Celsius). For example, applying ANR overshooting to one branch refers to adjusting (e.g., increasing or decreasing according to ANR overshooting configuration) the ANR of a specific branch such that controller 100 can adjust to commands from SCR system 52 (e.g., delivery mechanism 56) to increase or decrease a certain amount of reductant feed to meet overshooting ANR, or to increase or decrease a certain amount of reductant feed based on overshooting ANR. With relatively high or low ANR values, the proportion of reductant relative to NOx The proportions increased or decreased respectively. The ANR value can be expressed as the ratio of the reducing agent to NO. x The ANR value used for over-control can be predefined by the administrator of controller 100 or updated according to instructions from operator I / O device 120. For example, the ANR value of one branch (e.g., a new target ANR value) can be over-controlled to 0, 0.1, 0.2, 0.4, 2, 3, etc. For example, 0 ANR means every 1 ppm NO x 0 ppm reducing agent, 0.4 ANR refers to 10 ppm NO x 4 ppm reducing agent, or 3 ANR, refers to 1 ppm NO. x 3 ppm reducing agent. In another example, if NO x The predefined amount is 10 ppm, so an ANR value of 0.2 corresponds to 10 ppm NO. x 2 ppm of reducing agent. In some embodiments, ANR overshoot control may involve controller 100 sending a command to SCR system 52 to stop the reducing agent dispensing for a certain duration based on a predefined ANR overshoot value of 0. The duration may be based on a predetermined value of NO that has been changed. x Value or CE value or based on timer value.

[0077] In some embodiments, controller 100 overrides the ANR for a predefined duration (e.g., 10 seconds, 20 seconds, etc.). In some other embodiments, controller 100 overrides the ANR until the CE of the overridden branch reaches a threshold (e.g., the lower threshold in step 208). For example, controller 100 may be configured to apply a relatively low ANR overriding value (e.g., 0, 0.1, or other values ​​below a specified threshold) to the first branch 22A (or one of the branches), causing a change (e.g., NO) x An increase in readings and / or a decrease in CE values ​​is expected to be observed on the overridden branch to identify sensor tampering within the post-processing system 22. The controller 100 monitors changes in the CE of the first branch 22A. In step 208, the controller 100 may detect that the CE of the first branch has decreased below a predetermined threshold (e.g., 5% or 10% lower than the calculated stable CE determined before applying ANR overriding) due to a reduction in the amount of reducing agent dispensed according to the ANR overriding value. In this case, NO associated with the first branch 22A... x Sensor 12 is located in the first branch 22A to detect a decrease in CE after the reducing agent dosage is reduced. Although the first branch 22A is used as an example above, ANR overriding can be applied to the second branch 22B, and controller 100 can perform similar operations as described above.

[0078] For simplicity, the examples in this document provide a relatively low ANR overshoot value to be applied to one of the branches. In some other examples, a relatively high ANR overshoot value (e.g., 2, 2.5, 3, or other values ​​above a specified threshold) may be applied to one of the branches. In this case, the controller 100 is configured to, for example, detect a potential increase in CE in the overshoot branch. Furthermore, for simplicity, the examples in this document provide a NO value associated with (e.g., expected on the first branch 22A) x The first NO of sensor 12 x Sensors and NO associated with the second branch x The second NO of sensor 12 x sensor.

[0079] Controller 100 can detect a decrease in CE in the overridden branch in the following scenarios: NO associated with the overridden branch x Sensor 12 is positioned as desired or anticipated. For example, if the first branch 22A is overridden, the controller 100 can be positioned at the first NO. x When the sensor is located in the first branch 22A, a decrease in CE in the first branch 22A is expected. In another example, if the second branch 22B is overridden, the controller 100 can be in the second NO... x When the sensor is located in the second branch 22B, the CE in the second branch 22B is expected to decrease.

[0080] In some embodiments, in scenarios where a sensor associated with the overridden branch is misaligned or shifted to another branch, the controller 100 may not detect a decrease in CE in the overridden branch. For example, if the first NO x The sensor was moved to the second branch 22B (or the second NO). x If the sensor is moved to the first branch 22A, then the first NO x NO measured by sensor x The amount is associated with the second branch 22B. Therefore, the controller 100 may not have observed or detected a decrease in CE in the first branch 22A because the first NO x The sensor measures NO downstream of the SCR catalyst component 50 in the second branch 22B. xIn this scenario, controller 100 is configured to start a timer (e.g., 10 seconds, 20 seconds, etc.) in response to the application of ANR overriding. If controller 100 does not detect a decrease in CE in the overridden branch when the timer expires, controller 100 may proceed to step 210 or step 214. In some embodiments, controller 100 may, for example, apply ANR overriding to another branch to detect a decrease in CE in that other branch. In response to the timer expiring or CE meeting a threshold (e.g., CE decreasing below a first threshold), controller 100 may reset the ANR value or remove the ANR overriding value.

[0081] In step 210, the controller 100 uses comparison logic (e.g., branch-to-branch comparison logic) to isolate CE changes caused by transient variations. This can be combined with... Figures 3-10 At least one of them further describes the comparison logic in detail. For example, controller 100 monitors or obtains the comparison logic with each branch (first NO) within a predefined duration in response to the application of ANR override control. x Sensor and second NO x The controller 100 retrieves the CE data associated with the sensor. The controller 100 determines the minimum CE value calculated for each branch during the predefined duration. The controller 100 compares the CE values ​​between branches to determine the difference. If the difference is at or above a predefined threshold (e.g., 10%, 20%, 30%, etc.), the controller 100 proceeds to step 214. In other cases, if the difference is less than the predefined threshold and steps 202-210 are performed as part of a first attempt, the controller 100 may proceed to step 212. In some other cases, the controller 100 may continue to step 214 during the first attempt.

[0082] In some embodiments, in step 212, controller 100 is configured to repeat or retry the attempt (e.g., initiate a second attempt) to confirm whether the fault detected in the first attempt was accurate or a false positive. For example, in the second attempt, controller 100 applies ANR overshoot to one branch of the branch using an ANR value similar to or different from the first attempt. In step 208 of the second attempt, controller 100 is configured with a relatively low threshold (e.g., 10%, 15%, 20%, etc.) to detect a CE drop in the overshoot branch as part of the confirmation process. In response to detecting a CE drop, controller 100 resets the ANR and proceeds to step 210. Similar to the first attempt, controller 100 determines the difference between the lowest CE values ​​of the first branch 22A and the second branch 22B.

[0083] In response to the comparison, controller 100 proceeds to step 214. In step 214, controller 100 generates a fault indication (setting a fault indicating sensor misalignment) or clears the fault indication (or stops the diagnostic operation without generating an indication). For example, if the difference (in the first or second attempt) is greater than or equal to a predefined threshold, controller 100 determines NO. x Sensor 12 is located at a desired position within the post-processing system 22. Otherwise, if the difference is less than a predefined threshold, controller 100 determines NO. x Sensor 12 is not at the desired location within the post-processing system 22. In this case, controller 100 is configured to generate information about NO. x Indication of sensor 12 misalignment (e.g., setting fault).

[0084] In various embodiments, the diagnostic process 200 is performed in response to starting the engine 20. For example, in response to an engine start event, the controller 100 may operate relative to a first branch 22A (e.g., ANR overshoot is applied to the first branch 22A). In response to a second engine start event, the controller 100 may operate relative to a second branch 22B (e.g., ANR overshoot is applied to the second branch 22B). In some cases, the controller 100 may operate relative to the first branch 22A in a first attempt and relative to the second branch 22B in a second attempt, and vice versa.

[0085] In some embodiments, the aftertreatment system 22 may include an ammonia sensor (not shown) located downstream of the SCR catalyst component 50, configured to measure the amount of reductant that has escaped through the SCR system 52. This is similar to the method described above for detecting NO. x In the event of sensor misalignment, controller 100 can be configured to detect ammonia sensor misalignment. For example, to detect ammonia sensor misalignment, controller 100 monitors the amount of reductant downstream of SCR catalyst component 50 or delivery mechanism 56. Controller 100 determines that the amount of reductant is stable for at least a predefined duration (e.g., within a predefined standard deviation). Controller 100 stores data (e.g., values, ranges, or measures) regarding the stable reductant dosage. Controller 100 applies a relatively high ANR overshoot value (e.g., 1.5, 2, 2.5, etc.) to one branch in the circuit to detect an increase in the measured reductant (e.g., reductant escape or supplied reductant). In some cases, controller 100 applies a relatively low ANR overshoot value (e.g., 0, 0.1, 0.5, etc.) to one branch in the circuit to detect a decrease in the measured reductant. Controller 100 compares changes in reductant between branches (e.g., similar to changes in...). Figures 3-4The comparison of CE (as described in the text) is used to determine whether the ammonia sensor in the overridden or non-overridden branch is misaligned. In some other embodiments, the controller 100 may use at least partially the measured amount of reducing agent to calculate the CE of the branch for NO detection. x Sensor misalignment (e.g., reducing agent escape can be a factor used to determine CE).

[0086] refer to Figure 3 It depicts the scene in Figure 1 Example graph 300 shows a healthy aftertreatment system 22 during ANR overrun. In this case, a healthy aftertreatment system refers to aftertreatment system 22 with untampered sensors (e.g., sensors associated with each branch are not shifted to another branch). Graph 300 shows the NO at the outlet of engine 20. x Sensor 12's engine output NO x The readings (304), the CE value (306) of the first branch 22A (e.g., the first SCR system 52A), the CE value (308) of the second branch 22B (e.g., the second SCR system 52B), the enable state of ANR overshoot control for the first branch 22A (e.g., enable = 1 and disable = 0) (310), and the enable state of ANR overshoot control for the second branch 22B (312). The data presented in graph 300 can be measured or obtained by various components of system 10, such as by sensors of post-processing system 22 or by controller 100. During or after performing ANR overshoot control (e.g., 0.1 ANR for 10 seconds) in the first branch 22A (e.g., to detect NO associated with the second branch 22B). x The tampering of sensor 12, because a drop in CE on one branch but not the other indicates that the sensor has not been tampered with), the controller 100 detects a drop in the CE value in the first branch 22A (at section 302), which is due to a reduction in the amount of reducing agent dispensed (e.g., a reduction in NO). x (Efficiency of conversion to pure nitrogen and water). In the second branch 22B, the controller 100 can be in the second NO... x The sensor did not detect a decrease in CE value when it was positioned as expected (in the second branch 22B) because the ANR override was only performed on the first branch 22A.

[0087] refer to Figure 4 It depicts the scene in Figure 1 The after-processing system has tampered sensors (e.g., NO) during ANR overrun control. xExample graph 400 of the aftertreatment system 22 (sensor misalignment). The data presented in graph 400 can be measured or obtained by various components of system 10, such as by sensors of aftertreatment system 22 or by controller 100. Similar to graph 300, graph 400 shows NO from the outlet of engine 20. x Sensor 12's engine output NO x The readings (404), the CE value (406) of the first branch 22A (e.g., the first SCR system 52A), the CE value (408) of the second branch 22B (e.g., the second SCR system 52B), the enable state (e.g., enabled = 1 and disabled = 0) of the ANR override control for the first branch 22A (410), and the enable state (412) of the ANR override control for the second branch 22B. In this graph 400, the second NO associated with the second branch 22B... x The sensor is misaligned or shifted to the first branch 22A. Similar to curve 300, the controller 100 applies ANR overshoot to the first branch 22A. During or after the ANR overshoot, the controller 100 (at section 402) detects a decrease in the CE value calculated for both the first branch 22A and the second branch 22B because the first NO x Sensor and second NO x The sensor is located in the first branch 22A with ANR overload control. Therefore, because a decrease in the CE value is observed in both the first branch 22A and the second branch 22B, the controller 100 determines the first NO associated with the first branch 22A. x Sensor and the second NO associated with the second branch 22B x The sensor is located in the first branch 22A (e.g., the second NO). x (The sensor has been shifted / tampered with).

[0088] exist Figure 3 and Figure 4 The operation performed is relative to the first branch 22A (e.g., ANR override control is performed in the first branch 22A). Figure 4 In the middle, given the first NO x The sensor, located in the first branch 22A, observed a decrease in CE. If the tampered system involves the first NO... x If the sensor is shifted to the second branch 22B, the controller 100 may not detect a decrease in the CE value of either branch. In this case, since ANR overshoot is applied in the first branch 22A and no decrease in CE is detected for either branch, the controller 100 determines NO. x Sensor 12 is located in the second branch 22B (first NO) x (Sensor misalignment). Although asFigure 3 and Figure 4 As shown, changes in the CE value are used to detect sensor tampering, but combinations such as... Figure 5 and Figure 6 As described, controller 100 can directly use NO. x Sensor readings (e.g., first NO) x Sensor readings and second NO x Sensor readings are used for sensor tampering detection.

[0089] refer to Figure 5 It depicts the scene in Figure 1 Use NO x Example curve 500 of the health of the post-processing system during ANR over-control in the post-processing system 22. Controller 100 is configured to monitor the NO in the corresponding branch. x Value (based on NO located downstream of SCR catalyst component 50) x NO measured by sensor 12 x Value). Graph 500 shows the NO from the outlet of engine 20. x Sensor 12's engine output NO x Reading (504), NO of the first branch 22A (e.g., downstream or at the outlet of the first SCR system 52A). x Value (506), NO of the second branch 22B (e.g., downstream or outlet of the second SCR system 52B). x Value (508), the enable state of ANR override control for the first branch 22A (e.g., enable=1 and disable=0) (510), and the enable state of ANR override control for the second branch 22B (512). As described herein, the monitored NO x The characteristics or behavior of the value may be the opposite of the CE value during or after ANR overshoot. For example, at section 502, controller 100 may apply ANR overshoot for a certain duration (e.g., 0.1 ANR for 10 seconds). ANR overshoot will cause NO x Peaks in sensor readings (e.g., NO) x An increase in the NO value is observed simultaneously with a decrease in the CE value. In this case, controller 100 applies ANR overshoot control on one branch (e.g., first branch 22A) to monitor NO. x Changes in value (e.g., NO) x (Increase in value). If NO occurs only for the over-controlled branch. x If the reading spikes, controller 100 determines NO. x Sensor 12 is positioned in the desired branch, as shown in graph 500.

[0090] refer toFigure 6 It depicts the scene in Figure 1 Use NO x The ANR overrun in the post-processing system of the value has been tampered with by the sensor (e.g., NO). x Example curve 600 of the post-processing system 22 (sensor misalignment). (Compared to...) Figures 3-5 Similar data can be shown in graph 600, such as NO from the outlet of engine 20. x Sensor 12's engine output NO x Reading (604), NO of the first branch 22A (e.g., downstream or at the outlet of the first SCR system 52A). x Value (606), NO of the second branch 22B (e.g., downstream or at the outlet of the second SCR system 52B). x Value (608), the enable state of ANR override control for the first branch 22A (e.g., enable = 1 and disable = 0) (610), and the enable state of ANR override control for the second branch 22B (612). In this case, graph 600 shows when NO x Sensor 12 indicates NO when it is shifted from the second branch 22B to the first branch 22A. x Example data for sensor readings. As shown in section 602, if NO appears in both branches (or not in either branch), x If the value spikes or increases (e.g., exceeds a threshold), controller 100 determines NO. x At least one of the sensors 12 is shifted. Because the overridden branch is the first branch 22A and spikes appear on both branches, the controller 100 determines a second NO associated with the second branch 22B. x The sensor was shifted to the first branch 22A due to the second NO. x The sensor output indicates the NO in the overridden branch. x The first NO of sensor 12 x Similar sensor readings. Various operations, features, or techniques performed using CE values ​​can similarly (additionally or alternatively) use NO. x Sensor readings (e.g., NO at the downstream or outlet of each branch of the SCR catalyst component 50) x (Reading) is used to perform the detection of NO. x Sensor displacement / tampering.

[0091] In the various embodiments discussed herein, the calculated CE value or measured NO for a particular branch x The value may or may not represent the actual CE of the SCR catalyst component 50 or the actual NO through a specific branch. xContent (e.g., NO from a branch associated with a branch) x The feedback from sensor 12 may not correspond to the actual tailpipe NO in the corresponding branch. x ). Calculated CE value or measured NO for a specific branch. x The value is relative to NO. x With regard to sensor 12, such as the first NO expected to be located in the first branch 22A and the second branch 22B respectively. x Sensor and second NO x sensor.

[0092] refer to Figure 7 It describes the detection Figure 1 Example process flowchart of the sensor tampering method 700 in the post-processing system. Figures 1-6 The process, operation, or steps can be performed by System 10, data processing system, cloud computing environment, or in conjunction with this document. Figure 2 Any other components of the described computing device (e.g., controller 100, I / O device 120, post-processing system 22, sensors, etc.) may be used to perform, operate, or execute the method. For example, additional or alternative operations of method 700 may be performed by one or more circuits of controller 100. Additionally or alternatively, some operations of method 700 may be performed by a remote device (such as a remote data processing system). Method 700 may include methods for monitoring NO. x Values ​​(e.g., alternative combinations) Figure 8 and Figure 2 The process of detecting sensor tampering (at least one of the CE values ​​mentioned above). Some operations of method 700 can be similar to combining Figure 6 The described operations are executed.

[0093] In step 702, the controller 100 is configured to determine that one or more enabling conditions are met. One or more enabling conditions may be met in response to the bed temperature of one or each of the first SCR system 52A and the second SCR system 52B being greater than or equal to a predetermined threshold.

[0094] The engine output NO can respond to at least one of the first branch 22A or the second branch 22B. x The value is greater than or equal to a predetermined threshold, satisfying one or more enabling conditions. Engine output NO. x The value is determined by at least one NO located at the outlet of engine 20, downstream of engine 20, or upstream of DOC component 30, and upstream of other components in each branch (e.g., SCR catalyst component 50, etc.). xSensor 12 measures. For example, predetermined thresholds can be configured by the administrator of controller 100 or based on configuration information from operator I / O device 120. In some embodiments, one or more enabling conditions may include the rate of change of bed temperature in SCR system 52 and / or the time between each attempt to detect sensor misalignment (e.g., attempts between performing the operations discussed herein). In some embodiments, enabling conditions may include additional or other enabling conditions besides those described above.

[0095] In step 704, controller 100 is configured to dispense reducing agent to the first SCR system 52A and the second SCR system 52B. Controller 100 initiates dispensing of reducing agent in response to the satisfaction of one or more enable conditions. Controller 100 commands a first dispenser (e.g., conveyor 56A) of the first branch 22A to dispense reducing agent to the first SCR system 52A. Controller 100 commands a second dispenser (e.g., conveyor 56B) of the second branch 22B to dispense reducing agent to the second SCR system 52B.

[0096] In some embodiments, an initial reductant dispensing operation is performed before considering one or more enabling conditions. For example, after starting engine 20, controller 100 may command the dispenser to dispense reductant to the first SCR system 52A and the second SCR system 52B. Then, for example, controller 100 determines whether one or more enabling conditions are met, and proceeds to step 706 and other steps.

[0097] In step 706, in response to the reducing agent dispensing at step 704, controller 100 is configured to determine the first NO. x Value and second NO x Value (or alternatively, a first CE value or a second CE value). Controller 100 based on the value from the first NO. x Sensors (e.g., NO associated with the first branch 22A) x Sensor 12 or expected to measure NO in the first branch 22A x NO x The first NO is determined by the reading or measurement result of sensor 12). x Value. Controller 100 based on the value from the second NO. x Sensors (e.g., NO associated with the second branch 22B) x Sensor 12 or expected to measure NO in the second branch 22B x NO x The reading of sensor 12) determines the second NO. x Value. First NO. x Value and second NO xThe values ​​represent the NO values ​​at the outlets of the first SCR system 52A and the second SCR system 52B, respectively. x The amount of NO measured at step 706. x The value is used to determine the steady-state CE of the first SCR and the second SCR. For example, controller 100 detects the first NO. x Sensor and second NO x sensor NO x Sensor readings remain within a predefined standard deviation (e.g., 2%, 3%, etc.) for at least a predefined duration. Controller 100 aggregates the NO values ​​for each branch. x Sensor readings (e.g., average, mean, median, etc.). For example, NO based on aggregation. x Sensor readings, controller 100 determines the first NO x Value and second NO x Value. In some cases, controller 100 uses the highest NO value for each branch. x Reading and / or lowest NO x Reading as the first NO x Value and second NO x Value. Controller 100 is configured to store the first NO. x Value and second NO x Values ​​to be used in conjunction with other NOs after applying ANR override control. x The values ​​are compared.

[0098] In some embodiments, controller 100 determines the first NO. x Value and second NO x Whether the value reaches a first predetermined threshold. The predetermined threshold can indicate steady-state conditions. In some embodiments, the predetermined threshold can be the standard deviation of each of the first and second NOx values ​​measured at step 706 from a previously determined NOx value at the first and second SCRs, respectively, or from a specified NOx value over a predetermined time period (e.g., 2 minutes). Controller 100 responds to the first NOx value. x Value and second NO x When the value reaches the predetermined threshold, proceed to step 708.

[0099] In step 708, controller 100 is configured, for example, in response to a first NO. x Value and second NO xThe reductant supply to the first SCR system 52A is adjusted over a time period (e.g., a first time period) when the value reaches a first predetermined threshold indicating a steady-state condition. In some other embodiments, the controller 100 is configured to adjust the supply to the second SCR system 52B instead of the first SCR system 52A. For the purposes of this example, the controller 100 sends a command to the first dispenser to adjust the supply to the first SCR system 52A. In this case, the controller 100 applies ANR overrun control to the first branch. The controller 100 adjusts the reductant supply amount to meet the ANR overrun control value. In some embodiments, the ANR overrun control value may be 0, such that the controller 100 is configured to, for example, stop the reductant supply to the first SCR system 52A.

[0100] In some cases, the time period used to adjust the reducing agent dosage (or apply ANR overshoot control) can be predefined by the administrator. In other cases, the time period is based on the time taken to change a predetermined percentage or amount (such as 5%, 10%, 15%, 20%, etc.) based on a first NOx value. In some embodiments, the predetermined percentage can be based on trials. In this case, in the first trial for detecting sensor misalignment, controller 100 is configured or set to a relatively low percentage (e.g., 5%) compared to the second trial (e.g., 10%, 15%, etc.).

[0101] In step 710, controller 100 is configured to measure the third NO. x Value and fourth NO x Values. For example, at the end of another time period (e.g., a second time period different from the first time period) after adjusting the dosing of the first SCR system 52A, the controller 100 measures a third NOx value of the first SCR system 52A based on readings from the first NOx sensor, and measures a fourth NOx value of the second SCR system 52B based on readings from the second NOx sensor. The second time period may be an extension of the first time period. The second time period is used or set to account for the reductant storage of the SCR system 52, because after adjusting the reductant dosing, a certain amount of reductant may remain in the SCR system storage device. In this case, spikes (for NOx) may not be captured until at least a certain amount of time after adjusting the reductant dosing. x Value) or decrease (for CE value), or NO x Other variations in sensor reading characteristics.

[0102] In some embodiments, the third NO x Value and fourth NO x The value can be represented by the first NO. x Sensor and second NO x The highest NO measured by the sensor during the time period (e.g., the first time period and / or the second time period)x Value. In some cases, the third NO. x Value and fourth NO x Values ​​can represent the average, mean, median, etc., of measurement results over a period of time.

[0103] In step 712, controller 100 is configured to determine NO. x The difference between values. For example, controller 100 determines the third NO. x Value and first NO x The first difference between the values. The controller determines the fourth NO. x Value and the second NO x The second difference between the values. These differences (e.g., the first and second differences) represent the NO values ​​before and after applying ANR control or adjusting the reducing agent dosing. x Changes or deviations in sensor readings.

[0104] In step 714, controller 100 is configured to generate information about the first NO. x Indication of sensor misalignment. Controller 100 is configured to perform an operation based on a first difference and a second difference regarding the first NO. x Determining whether the sensor is misaligned. For example, controller 100 responds to a first difference greater than a predetermined threshold (e.g., NO). x The first NO is determined by the maximum or upper limit of the quantity or percentage and the second difference being less than a predetermined threshold. x The sensor is not misaligned. In this case, if the first NO... x Sensor and second NO x If the sensor is located at the desired location (e.g., its associated branch), then it originates from the first NO. x Sensor and second NO x The sensor readings were within expectations.

[0105] In some embodiments, controller 100 determines a first difference between a first CE value calculated before ANR overshoot and a third CE value calculated during or after ANR overshoot. Controller 100 determines a second difference between a second CE value calculated before ANR overshoot and a fourth CE value calculated during or after ANR overshoot. The first and third CE values ​​are obtained using data from a first NO... x The sensor readings are calculated, and the second and fourth CE values ​​are obtained using data from the second NO. x The sensor readings are calculated. Controller 100 determines a second NO in response to a first difference being less than a predetermined threshold (e.g., the lower limit of the CE value) and a second difference being at or above the predetermined threshold. x The sensor is not misaligned.

[0106] In some embodiments, the controller 100 determines a second NO in response to determining that the difference between the second difference and the first difference is greater than a predetermined threshold (e.g., a lower limit or threshold for the amount or percentage of the difference). x The sensor is not misaligned. In some embodiments, the controller 100 responds to determining that a first difference is greater than a predetermined threshold (indicating a first NO in response to a change in the reducing agent supply). x The first NO is determined by the difference between the sensor reading and the second difference being less than another predetermined threshold. x Sensor misalignment. In this case, because the first difference and the second difference are similar to each other (e.g., the difference between them is less than a threshold), the controller 100 determines the first NO. x Sensor and second NO x The sensor is in a similar location (e.g., in the first branch 22A). Therefore, the controller 100 is configured to generate an indication of sensor misalignment.

[0107] In various embodiments, similar operations can be performed to determine the first NO. x The sensor may be misaligned, for example by adjusting the reductant supply to the second SCR system 52B instead of the first SCR system 52A, or based on the absence of spikes or drops in either branch after adjusting the reductant supply to the first SCR system 52A. Therefore, the controller 100 is configured to perform a similar operation to detect the first NO. x Sensor (or other NO in other branches) x Whether the sensor is misaligned or tampered with. In various arrangements, this can be combined with... Figure 8 The operation, technique, or features of method 700 shall be described in further detail.

[0108] Figure 7 It is used for execution Figure 8 Example process flowchart of the sensor tamper detection method 800. Figures 1-7 The process, operation, or steps can be performed by System 10, data processing system, cloud computing environment, or in conjunction with this document. Figure 2 Any other components of the described computing device (e.g., controller 100, I / O device 120, post-processing system 22, sensors, etc.) may perform, operate, or execute the method. For example, additional or alternative operations of method 800 may be performed by one or more circuits of controller 100. Additionally or alternatively, some operations of method 800 may be performed by a remote device (such as a remote data processing system). In various embodiments, method 800 may represent a sequence of instructions or steps to be performed by one or more components or other devices of system 10. Method 800 may include at least... Figure 9 A similar or additional process described.

[0109] In step 802, controller 100 initiates a diagnostic process for detecting sensor misalignment. Controller 100 may initiate the diagnostic process in response to starting engine 20 (e.g., key “ON”). Controller 100 sets / resets variables configured to default values. For example, controller 100 sets the fail count variable and the pass count variable to zero.

[0110] In step 804, controller 100 determines whether one or more enabling conditions are met. In this case, enabling conditions include the bed temperature of the SCR system 52 (or SCR catalyst assembly 50) in each branch and the engine output NO. x If the bed temperature is at or above a predetermined temperature threshold and the engine outputs NO... x At or above the predetermined NO x If the threshold is met, controller 100 proceeds to step 806. Otherwise, controller 100 continues to monitor enabling conditions until these conditions are met. Controller 100 may consider other enabling conditions, such as temperature fluctuations, temperature changes, or engine output NO. x The rate of change, etc.

[0111] In step 806, in response to the fulfillment of an enable condition, controller 100 determines whether the CE value calculated for the branch is above a certain CE threshold (e.g., 80%, 90%, 95%, etc.) and / or whether the monitored (calculated) CE of the branch is relatively stable (e.g., the standard deviation of the CE value measured over a predefined duration is less than a predetermined threshold, such as 2%, 3%, etc.). The CE value and / or the standard deviation of the CE value may be part of the enable condition. If the CE value is at or above the CE threshold and / or the standard deviation of the CE value over a predefined duration is less than the predetermined threshold, controller 100 proceeds to step 808. Otherwise, if at least one or both of these conditions are not met, controller 100 returns to step 804 or continues monitoring the CE of each branch.

[0112] In some embodiments, the controller 100 monitors the NO of each branch. x Sensor reading, not CE value. NO. x Sensor readings can come from the NO outlet located at at least one of the first SCR system 52A and / or the second SCR system 52B. x Sensor 12. In this case, controller 100 determines the NO measured for each branch within a certain predefined duration. x Whether the value is within the predetermined standard deviation threshold and / or the NO of each branch x Is the value at or above NO?x The threshold is set to proceed to step 808 or repeat at least one of steps 804 or 806.

[0113] In step 808, the controller 100 obtains the calculated CE value (or NO) for each branch during the stabilization window. x The controller 100 determines at least one CE value (or NO) for each branch during the stabilization window. x Values ​​(e.g., average, median, etc.). Controller 100 stores the CE values ​​of the first branch 22A and the second branch 22B in memory. For example, a first CE value is calculated for the first branch 22A, and a second CE value is calculated for the second branch 22B.

[0114] In step 810, controller 100 overrides the ANR for one branch in the branch. For the purpose of providing an example herein, controller 100 overrides the ANR for the first branch 22A. By overriding the ANR, controller 100 is configured to send a command to a dispenser (e.g., a first dispenser) to adjust the reductant dosing amount. In some cases, controller 100 is configured to adjust the reductant dosing amount to the SCR system 52. Controller 100 is configured to initiate an ANR monitoring timeout window (e.g., a first time period) in response to the application of ANR overriding. In some cases, the ANR monitoring timeout window is based on or corresponds to the monitored CE value falling below a predetermined percentage (such as 5%, 10%, etc.) (or NO). x The time required for the value to peak above the predetermined percentage. In some other cases, the ANR monitoring timeout window can be a predefined duration. Controller 100 is configured to reset ANR overshoot or restart reductant dispensing at the end of the first time period.

[0115] In step 812, controller 100 determines whether a spike detection window has started. The spike detection window (e.g., a second time period) may start in response to an ANR monitoring timeout window. For example, the spike detection window may start at the end of a first time period. If the second time period has started, controller 100 proceeds to step 814. Otherwise, controller 100 remains in step 812 until the end of the first time period, for example, to begin the second time period. Controller 100 is configured to detect any spikes in first branch 22A or second branch 22B during or at the end of the second time period.

[0116] During the second time period, controller 100 determines the NO of the corresponding SCR system 52. x At least one of the values ​​or CE values. For example, controller 100 can determine the third NO of the first SCR system 52A after the end of the second time period. x Value and the fourth NO of the second SCR system 52Bx Value. In another example, depending on the configuration of controller 100, controller 100 can determine the third CE value of the first SCR system 52A and the fourth CE value of the second SCR system 52B after the end of the second time period.

[0117] Furthermore, controller 100 is configured to determine the value of the first branch 22A obtained before and after ANR overshoot (e.g., NO). x The first difference is between the ANR value (or CE value) and the second difference is between the values ​​obtained before and after the ANR overshoot (applied to the first branch 22A) in the second branch 22B. The first and second differences are used to determine whether a spike is detected in the first branch 22A or the second branch 22B, respectively. These differences can be expressed as a percentage or a quantity.

[0118] In step 814, controller 100 determines whether a spike was detected for both branches within the spike detection window (e.g., spike detection within a second time period). For example, controller 100 compares a first difference and a second difference with a predetermined threshold (e.g., 5%, 10%, 15%, or other percentage difference). If the first difference and the second difference associated with the first branch 22A and the second branch 22B, respectively, exceed the predetermined threshold, controller 100 determines that a spike was detected for both branches (proceed to step 820). If at least one of the first difference and / or the second difference does not exceed the predetermined threshold, controller 100 determines that no spike was detected on either branch (proceed to step 816).

[0119] In step 816, during or at the end of the second time period, controller 100 determines whether a spike is detected on the overridden branch (e.g., in this example, the first branch 22A) and not on another branch. If a spike is detected for the first branch 22A and not the second branch 22B, controller 100 determines the first NO. x Sensor and second NO x The sensor is correctly positioned in the first branch 22A and the second branch 22B. In this case, the controller 100 proceeds to step 822. If no spike is detected in either branch, the controller 100 proceeds to step 818.

[0120] In step 818, controller 100 determines whether the second time period has ended (e.g., whether the spike detection window has ended). If the second time period has ended and controller 100 has not detected any spikes, controller 100 proceeds to step 828. Otherwise, controller 100 continues monitoring for the third NO. x Value and fourth NO x The value or CE value is used to determine or update the first difference and the second difference to potentially detect spikes (e.g., return to step 814).

[0121] In step 820, in response to detecting spikes in the two branches, controller 100 determines whether the difference between the peak (or bottom) of the spike in each branch is greater than or equal to a predetermined threshold (e.g., percentage or quantity difference). For example, the third NO x The value or the third CE value can respectively represent the peak or trough of the first branch 22A. The fourth NO... x The value or the fourth CE value can represent the peak or trough of the spike in the second branch 22B, respectively. Controller 100 compares the peaks or troughs between branches to determine the difference. If the difference is at or above a predetermined threshold (e.g., a minimum difference threshold), controller 100 proceeds to step 822. Otherwise, controller 100 proceeds to step 828.

[0122] In step 822, controller 100 determines NO. x Sensor 12 is positioned at its desired or anticipated location. Therefore, controller 100 will set a counter variable to 1 and / or clear the fault. In this case, the fault may include providing the administrator with the following notification: an error has been detected when applying sensor tamper detection operation. x Tampering with sensor 12. In response to a triggered fault, an indication (e.g., visual, audio, or tactile feedback) may be presented to the operator of system 10. In step 824, controller 100 determines whether engine 20 is off. Controller 100 may wait until engine 20 is off until proceeding to step 826. In step 826, controller 100 is configured to perform diagnostic procedures on another branch (e.g., second branch 22B), such as ANR overshoot control on the other branch.

[0123] In step 828, in response to the peak difference between branches being less than a predetermined threshold or the absence of spikes on the two branches after the second time period expires, controller 100 increments the failure count variable. For the first attempt at the diagnostic process, the failure count variable increments to 1. For the second attempt at the diagnostic process, if controller 100 reaches this step, the failure count variable increments to 0 (e.g., a binary variable) or 2.

[0124] In step 830, controller 100 determines whether the failure count variable is 1. If the failure count is 1, controller 100 proceeds to step 832. Otherwise, controller 100 proceeds to step 834.

[0125] In step 832, controller 100 may wait for a duration (e.g., a time delay / interval between attempts) to begin a second attempt. In response to the time between attempts exceeding a predefined threshold, controller 100 returns to step 804 to perform another attempt. In the second attempt, controller 100 may adjust or set parameters for NO. x Another predetermined threshold for the value to increase or CE to decrease (e.g., from 5% to 10% or to 15%, etc.). After performing the second attempt, if controller 100 reaches step 828, the failure count is incremented to 0. Therefore, controller 100 proceeds to step 830, and then to step 834.

[0126] In step 834, controller 100 generates, sets, and / or latches indications of faults in response to multiple diagnostic processes. In this case, controller 100 may generate a second NO. x Sensor misalignment (or when performing diagnostics on the second branch 22B, the first NO) x Indication of sensor misalignment.

[0127] In step 836, controller 100 determines whether engine 20 is off. When engine 20 is off, controller 100 proceeds to step 838. In step 838, controller 100 may perform diagnostics on the same branch. For example, controller 100 may perform diagnostics on the same branch (when the enable condition is met) to determine NO. x Is sensor 12 still misaligned?

[0128] refer to Figure 7 The description shows the execution Figure 8 and Figure 10 Example curve 900 for the first diagnostic case of the method. Curve 900 shows the NO at the outlet or downstream of engine 20. x Sensor 12 measures the engine output NO x (908), the bed temperature of the first SCR system 52A in the first branch 22A (910), the bed temperature of the second SCR system 52B in the second branch 22B (912), the CE value associated with the first SCR system 52A (914), and the CE value associated with the second SCR system 52B (916). In this example, the controller 100 applies ANR overshoot control to the first branch 22A (e.g., performs diagnostics on the first branch 22A) to determine NO on the second branch 22B. xIs sensor 12 misaligned? As shown in section 902, controller 100 can determine whether enabling conditions, such as the bed temperature of SCR system 52 and / or the CE value associated with SCR system 52, are met. In response to determining that the enabling conditions are met, controller 100 can initiate the first attempt at sensor tamper detection. For example, controller 100 monitors the CE value of a branch to identify when the CE value is considered stable (e.g., the CE value of the branch is within a standard deviation threshold). Once the CE value is considered stable, for example at time (904), controller 100 can acquire and store the CE value (e.g., the first CE value of the first branch 22A and the second CE value of the second branch 22B) during the stable period as part of the first attempt. Subsequently, controller 100 applies ANR overshoot control on one branch of the branch (e.g., on the first branch 22A in this example) for at least a first time period. Controller 100 can monitor changes in the CE values ​​of both branches during a second time period (as shown in section (906)). In this scenario, the controller 100 can determine the third CE value of the first branch 22A and the fourth CE value of the second branch 22B during or after the application of ANR override control. For example, the third and fourth CE values ​​can represent the lowest CE values ​​in the respective branches.

[0129] Controller 100 calculates a first difference between a first CE value and a third CE value, representing the change in CE of the first SCR system 52A during or after ANR overshoot. Controller 100 calculates a second difference between a second CE value and a fourth CE value, representing the change in CE of the second SCR system 52B during or after ANR overshoot. As shown in graph 900, controller 100 detects a decrease in CE of the first branch 22A (e.g., the first difference is greater than a predetermined threshold), while there is no decrease in CE of the second branch 22B (e.g., the second difference is less than a predetermined threshold). Because the CE decrease occurs on the overshoot branch rather than on the non-overshoot branch (e.g., a branch without ANR overshoot), controller 100 determines the NO associated with the branch. x Sensor 12 is correctly positioned (e.g., it has not been tampered with or displaced).

[0130] refer to Figure 7 The description shows the execution Figure 8 and Figure 9 Example curve 1000 for the second diagnostic case of the method. Curve 1000 may include... Figure 9 Related data of similar type. For example, graph 1000 shows the engine output NO. x(1012), bed temperature of the first SCR system 52A (1014), bed temperature of the second SCR system 52B (1016), CE value associated with the first SCR system 52A (1018), and CE value associated with the second SCR system 52B (1020). In this example, controller 100 applies ANR overshoot control to the first branch 22A. This can be at least combined with... Figure 10 Similar description Figure 9 The various operations described in the document.

[0131] At section 1002, controller 100 determines one or more enabling conditions (e.g., engine output NO in this case). x (e.g., engine output NO) does not meet the threshold. x Enable threshold. In this case, controller 100 aborts the sensor tamper detection attempt. As part of the enable condition, controller 100 may wait for at least a predefined duration to perform another attempt (retry attempt) at section 1004. At section 1004, controller 100 monitors a stable period of CE values ​​associated with the first branch 22A and the second branch 22B. In response to determining that the CE values ​​are stable within the predefined duration, at (1008), controller 100 applies ANR override control during the first time period and monitors changes in the CE values ​​during the second time period, such as at least in combination with Figure 11 As described. In this case, the controller 100 can determine that the third CE value of the first branch 22A and the fourth CE value of the second branch 22B are less than a predetermined threshold, and indicate the first NO. x Sensor and second NO x The sensors may be in the same branch (e.g., capturing similar data).

[0132] To confirm the attempt at section 1004, controller 100 initiates a second attempt at section 1006. A stable period can be detected at (1010). In any subsequent attempts to confirm detected sensor tampering, controller 100 can apply relatively low or relatively high ANR overshoot to the same branch (e.g., reduce from 0.4 ANR to 0.1 ANR, increase from 1.5 ANR to 2 ANR, or stop reducing agent dispensing for a relatively long period, etc.). A process similar to the first attempt for sensor tampering detection can be performed for the second attempt. In this case, controller 100 determines that the decrease in the CE value of the first branch 22A (e.g., the overshoot branch) is below a predetermined threshold. Furthermore, controller 100 determines that the difference between the first difference and the second difference (or the third CE value and the fourth CE value) is greater than or equal to a predetermined threshold, which can indicate NO. x Sensor 12 measures NO on different branches xTherefore, in response to determining that the difference between the second difference and the first difference is greater than a predetermined threshold, the controller 100 determines the second NO. x The sensor did not shift because from the second NO x No decrease in CE value was observed in the sensor readings.

[0133] refer to Figure 7 The description shows the execution Figure 8 and Figures 9-10 Example curve 1100 for the third diagnostic case of the method. Curve 1100 shows the comparison with... Figure 9 At least one similar type of data. For example, graph 1100 shows the engine output NO. x (1108), bed temperature of the first SCR system 52A (1110), bed temperature of the second SCR system 52B (1112), CE value associated with the first SCR system 52A (1114), and CE value associated with the second SCR system 52B (1116). In this example, controller 100 applies ANR overload control to the first branch 22A, and the second NOx sensor is shifted to the first branch 22A. At least... Figure 10 and Figure 11 Similar description Figure 9 The various operations described in the document.

[0134] At section 1102, controller 100 detects at (1008) that the CE value is stable and applies ANR overrun in response to the detection of a stable window. Controller 100 overruns the ANR (or stops the first dispenser from dispensing reducing agent to the first SCR system 52A) for a first time period. As shown, the first time period is the time when the CE of the first branch 22A drops below a predetermined threshold (e.g., the amount of CE drop is greater than the predetermined threshold) (such as 5% on the first attempt). Controller 100 may reset or remove the ANR overrun in response to the CE value of the overrun branch reaching a predetermined CE drop threshold. Figure 10 and / or Figure 12 In at least one of the following configurations, controller 100 determines a first difference between a first CE value and a third CE value in the first branch 22A and a second difference between a second CE value and a fourth CE value in the second branch 22B (e.g., CE values ​​before and after ANR overshoot). In this case, controller 100 determines that the difference between the first difference and the second difference is less than a predetermined threshold, indicating that sensor tampering has been detected.

[0135] To confirm the result of the first attempt, controller 100 performs a second attempt at section 1104. In the second attempt, a similar process to the previous attempt can be performed, but with a relatively lower ANR value (or the reducing agent dispensing is stopped for a relatively longer duration). Compared to the first attempt, using a relatively lower ANR value, controller 100 is configured to adjust the dispensing to the first branch 22A for a relatively longer duration or adjust the dispensing to the first branch 22A by a larger amount. For example, as shown, controller 100 can apply ANR overshoot control in a third time period based on the time it takes for the CE of the first branch 22A to drop below a relatively low predetermined threshold (such as 10%) during the second attempt. In this case, at the end of the fourth time period after adjusting the dispensing in the third time period, controller 100 also detects a result similar to the first attempt. For example, controller 100 detects that the CE drop on the first branch 22A is greater than a predetermined CE drop threshold. Furthermore, controller 100 determines (the NO for the first branch 22A in the second attempt)... x The third difference (calculated value) and (NO in the second attempt for the second branch 22B) x The difference between the fourth and third differences (calculated values) is less than a predetermined difference threshold. Because the difference between the third and fourth differences is less than the predetermined difference threshold in both trials, controller 100 determines the second NO. x The sensor was shifted in the first branch 22A because of the second NO x The sensor readings and the first NO used to calculate the CE value x The sensor readings are consistent.

[0136] refer to Figure 7 The description shows the execution Figure 8 and Figures 9-11 Another example of the fourth diagnostic case using this method is shown in graph 1200. Graph 1200 illustrates the comparison with... Figures 9-11 At least one similar type of data. For example, graph 1200 shows the engine output NO. x (1208), bed temperature of the first SCR system 52A (1210), bed temperature of the second SCR system 52B (1212), CE value associated with the first SCR system 52A (1214), and CE value associated with the second SCR system 52B (1216). In this example, controller 100 applies ANR overshoot control to the first branch 22A, and the first NOx sensor is shifted to the second branch 22B. This can be combined with... Figure 12 At least one of them is similarly described ​ The various operations described in the document.

[0137] At section 1202, controller 100 detects that the CE value is stable at (1206) after one or more enable conditions are met. Controller 100 applies ANR overrun in response to detecting a stable window at (1206). Controller 100 overruns the ANR for a certain period (or stops the first dispenser from dispensing reducing agent to the first SCR system 52A). In this case, controller 100 may not detect a decrease in the CE value from the first branch 22A because the first NO... x The sensor is located in the second branch 22B. Therefore, after a pre-configured expiration time for ANR overshoot control, the controller 100 can determine a first difference between the first CE value and the third CE value (e.g., CE before and after ANR overshoot control) of the first branch 22A. In this case, the controller 100 determines that the first difference is less than a predetermined threshold. The controller 100 determines a first NO based on the first attempt. x The sensor may have been moved to the second branch 22B because no decrease in CE value was observed for the overridden branch.

[0138] In the second attempt at section 1204, a process similar to the first attempt can be performed. In some cases, for the second attempt, controller 100 may apply a different ANR value (e.g., a relatively low ANR value) or set a different expiration timer for ANR overrun. As shown in graph 1200, similar to the first attempt, controller 100 determines, after the ANR overrun timer expires, that the first difference between the first CE value obtained in the stability window and the third CE value obtained during or after ANR overrun (e.g., in the second time period) is less than a predetermined threshold. Therefore, controller 100 can detect potential NO. x The sensor shifts from the first branch 22A to the second branch 22B because of the shift from the first NO... x The sensor readings did not reflect the expected NO in the overridden branch. x The amount (and CE).

[0139] In some embodiments, in response to determining that the CE value associated with the overridden branch has not decreased below a predetermined CE decrease threshold, controller 100 may perform ANR overriding on another branch (e.g., second branch 22B instead of first branch 22A). For example, controller 100 may switch the ANR overriding branch after a first attempt, a second attempt, or the next engine start event. In some cases, controller 100 may perform ANR overriding on the same branch after the next engine start event. In this case, if the characteristics of the CE value remain the same (e.g., the CE decrease is less than a predetermined threshold or the difference between the first and second differences is less than a predetermined difference threshold), controller 100 may determine the NO associated with the overridden branch.x Sensor 12 is shifted to a non-overclocked branch to monitor NO passing through the post-processing system 22. x The expected change in content was not reflected in NO from the over-controlled branch. x sensor NO x reading.

[0140] III. Construction of Example Implementations

[0141] While this specification contains many specific implementation details, these should not be construed as limiting the scope of what can be claimed, but rather as descriptions of features specific to particular embodiments. Some features described in the context of individual embodiments may also be implemented in combination in a single implementation. Conversely, various features described in the context of a single implementation may also be implemented individually or in any suitable sub-combination in multiple embodiments. Furthermore, while features may be described as functioning in certain combinations and even initially claimed as such, one or more features from a claimed combination may be removed from the combination in certain circumstances, and the claimed combination may be for sub-combinations or variations thereof.

[0142] As used herein, the terms “substantially,” “approximately,” “about,” 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, recalling 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 invention as set forth in the appended claims.

[0143] As used herein, the term "joining" refers to two components being directly or indirectly connected to each other. Such a connection can be static (e.g., permanent) or movable (e.g., removable or releasable). Such a connection can be achieved when two components, or two components and any additional intermediate components, are integrally formed into a single unit, or when two components, or two components and any additional intermediate components, are attached to each other.

[0144] As used herein, the terms "fluid connection" and the like refer to two components or objects having a path formed between them in which a fluid (e.g., air, exhaust gas, liquid reducing agent, gaseous reducing agent, aqueous reducing agent, gaseous ammonia, etc.) can flow with or without an intermediate component or object. Examples of fluid connectors or configurations used to achieve fluid communication may include pipes, channels, or any other suitable components for enabling fluid flow from one component or object to another.

[0145] It is important to note that the construction and arrangement of the systems shown in the various example embodiments are illustrative only and not restrictive in nature. Protection is intended for all changes and modifications falling within the spirit and / or scope of the described embodiments. It should be understood that some features may not be essential, and embodiments lacking various features may be contemplated as being within the scope of this application, defined by the appended claims. When the term "part" is used, unless otherwise expressly stated, an item may include a part and / or the entire item.

[0146] Furthermore, the term "or" is used in its inclusive sense (rather than its exclusive sense) such that when used, for example, to connect a list of elements, the term "or" means one, some, or all of the elements in the list. Unless otherwise specifically stated, connecting language such as the phrase "at least one of X, Y, and Z" is understood in the context to generally convey that items, terms, etc., can be X, Y, Z, X and Y, X and Z, Y and Z, or X, Y, and Z (i.e., any combination of X, Y, and Z). Therefore, unless otherwise stated, such connecting language is generally not intended to imply that certain embodiments require the presence of at least one of X, at least one of Y, and at least one of Z.

[0147] Additionally, unless otherwise stated, the range of values ​​used herein (e.g., W to P, etc.) includes its maximum and minimum values ​​(e.g., W to P includes W and includes P, etc.). Furthermore, unless otherwise stated, the range of values ​​(e.g., W to P, etc.) is not necessarily required to include intermediate values ​​within the range (e.g., W to P may include only W and P, etc.).

Claims

1. A post-processing system, comprising: The first branch includes a first SCR system and a first dispenser; The second branch includes a second SCR system and a second dispenser; and The controller is configured to: Determine that one or more enabling conditions are met; In response to the satisfaction of one or more enabling conditions, the reducing agent is dispensed into the first SCR system using the first dispenser and into the second SCR system using the second dispenser; In response to the supply to the first SCR system and the supply to the second SCR system, a first NOx value of the first SCR system is determined based on readings from a first NOx sensor associated with the first branch, and a second NOx value of the second SCR system is determined based on readings from a second NOx sensor associated with the second branch. In response to the first NOx value and the second NOx value reaching a first predetermined threshold, the supply to the first SCR system is adjusted within a first time period; At the end of the second time period after adjusting the feed to the first SCR system, a third NOx value of the first SCR system is measured based on the reading from the first NOx sensor, and a fourth NOx value of the second SCR system is measured based on the reading from the second NOx sensor. Determine the first difference between the third NOx value and the first NOx value; Determine the second difference between the fourth NOx value and the second NOx value; and An indication of whether the second NOx sensor has been shifted is generated based on the first difference and the second difference.

2. The post-processing system according to claim 1, wherein, The controller is configured to determine that the first NOx sensor and the second NOx sensor have not been shifted in response to the first difference being greater than a second predetermined threshold and the second difference being less than the second predetermined threshold.

3. The post-processing system according to claim 1, wherein, The controller is configured to determine that the first NOx sensor and the second NOx sensor have not been shifted in response to determining that the difference between the second difference and the first difference is greater than a third predetermined threshold.

4. The post-processing system according to claim 1, wherein, The controller is configured to determine that the second NOx sensor has been shifted in response to determining that the first difference is greater than a fourth predetermined threshold and the difference between the second difference and the first difference is less than a fifth predetermined threshold.

5. The post-processing system according to any one of claims 1 to 4, wherein, The one or more enabling conditions are met in response to the bed temperature in each of the first SCR system and the second SCR system being greater than a sixth predetermined threshold.

6. The post-processing system according to any one of claims 1 to 4, wherein, The one or more enabling conditions are met in response to the engine output NOx value of each of the first branch and the second branch being greater than a seventh predetermined threshold.

7. The post-processing system according to any one of claims 1 to 4, wherein, The first time period is the time required for a predetermined percentage to change based on the first NOx value.

8. The post-processing system according to claim 4, wherein, After determining that the first difference is greater than the fourth predetermined threshold and the difference between the second difference and the first difference is less than the fifth predetermined threshold, the controller is further configured to: Adjust the supply to the first SCR system during the third time period; After adjusting the feed rate of the first SCR during the third time period, a fifth NOx value of the first SCR system is measured based on the reading from the first NOx sensor, and a sixth NOx value of the second SCR system is measured based on the reading from the second NOx sensor. Determine the third difference between the fifth NOx value and the first NOx value; Determine the fourth difference between the sixth NOx value and the second NOx value; and An indication of whether the second NOx sensor has been displaced is generated based on the third difference and the fourth difference.

9. A method for detecting sensor tampering, comprising: The controller determines whether one or more enable conditions are met; In response to the fulfillment of one or more enabling conditions, the controller uses a first dispenser to dispense reducing agent to the first SCR system of the first branch and uses a second dispenser to dispense reducing agent to the second SCR system of the second branch; In response to the supply to the first SCR system and the supply to the second SCR system, the controller determines a first NOx value of the first SCR system based on readings from a first NOx sensor associated with the first branch, and determines a second NOx value of the second SCR system based on readings from a second NOx sensor associated with the second branch; In response to the first NOx value and the second NOx value reaching a first predetermined threshold, the controller adjusts the supply to the first SCR system within a first time period; At the end of the second time period after adjusting the supply to the first SCR system, the controller measures a third NOx value of the first SCR system based on the reading from the first NOx sensor, and measures a fourth NOx value of the second SCR system based on the reading from the second NOx sensor. The controller determines the first difference between the third NOx value and the first NOx value; The controller determines the second difference between the fourth NOx value and the second NOx value; and The controller generates an indication as to whether the second NOx sensor has been displaced based on the first difference and the second difference.

10. The method of claim 9, comprising: In response to the first difference being greater than a second predetermined threshold and the second difference being less than the second predetermined threshold, the controller determines that the first NOx sensor and the second NOx sensor have not been shifted.

11. The method of claim 9, comprising: In response to determining that the difference between the second difference and the first difference is greater than a third predetermined threshold, the controller determines that the first NOx sensor and the second NOx sensor have not been shifted.

12. The method of claim 9, comprising: In response to determining that the first difference is greater than a fourth predetermined threshold and the difference between the second difference and the first difference is less than a fifth predetermined threshold, the controller determines that the second NOx sensor has been shifted.

13. The method according to any one of claims 9 to 12, wherein, The one or more enabling conditions are met in response to the bed temperature in each of the first SCR system and the second SCR system being greater than a sixth predetermined threshold.

14. The method according to any one of claims 9 to 12, wherein, The one or more enabling conditions are met in response to the engine output NOx value of each of the first branch and the second branch being greater than a seventh predetermined threshold.

15. The method according to any one of claims 9 to 12, wherein, The first time period is the time required for a predetermined percentage to change based on the first NOx value.

16. A controller, comprising: One or more processors; as well as One or more memory devices coupled to the one or more processors, the one or more memory devices storing instructions that, when executed by the one or more processors, cause the one or more processors to: Determine that one or more enabling conditions are met; In response to the satisfaction of one or more enabling conditions, a reducing agent is dispensed to the first SCR system of the first branch using a first dispenser and a reducing agent is dispensed to the second SCR system of the second branch using a second dispenser; In response to the supply to the first SCR system and the supply to the second SCR system, a first NOx value of the first SCR system is determined based on readings from a first NOx sensor associated with the first branch, and a second NOx value of the second SCR system is determined based on readings from a second NOx sensor associated with the second branch. In response to the first NOx value and the second NOx value reaching a first predetermined threshold, the supply to the first SCR system is adjusted within a first time period; At the end of the second time period after adjusting the feed to the first SCR system, a third NOx value of the first SCR system is measured based on the reading from the first NOx sensor, and a fourth NOx value of the second SCR system is measured based on the reading from the second NOx sensor. Determine the first difference between the third NOx value and the first NOx value; Determine the second difference between the fourth NOx value and the second NOx value; and An indication of whether the second NOx sensor has been shifted is generated based on the first difference and the second difference.

17. The controller according to claim 16, wherein, When the instruction is executed by the one or more processors, the one or more processors determine that the first NOx sensor and the second NOx sensor have not been shifted in response to the first difference being greater than a second predetermined threshold and the second difference being less than the second predetermined threshold.

18. The controller according to claim 16, wherein, When the instruction is executed by the one or more processors, the one or more processors: in response to determining that the difference between the second difference and the first difference is greater than a third predetermined threshold, determine that the first NOx sensor and the second NOx sensor have not been shifted.

19. The controller according to claim 16, wherein, When the instruction is executed by the one or more processors, the one or more processors: in response to determining that the first difference is greater than a fourth predetermined threshold and that the difference between the second difference and the first difference is less than a fifth predetermined threshold, determine that the second NOx sensor has been shifted.

20. The controller according to any one of claims 16 to 19, wherein, The one or more enabling conditions are met in response to the bed temperature in each of the first SCR system and the second SCR system being greater than a sixth predetermined threshold.

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