SYSTEMS AND METHODS FOR DETECTING FAULTS IN DUAL DOSING SYSTEMS

Abstract

A post-treatment system comprises a first dosing system with a first metering unit, a first pressure sensor, and a first metering pump; a second dosing system with a second metering unit, a second pressure sensor, and a second metering pump; and a control unit. The control unit meters reducing agents into an SCR system. The control unit determines a first pressure value associated with the first metering system and a second pressure value associated with the second metering system. The control unit applies a target pressure override to the first metering unit. The control unit determines a third pressure value associated with the first metering system and a fourth pressure value associated with the second metering system. The control unit determines the difference between the third and fourth pressure values.The control unit compares the difference with a second threshold and generates a display indicating a fault in the first dosing system, based on the comparison.

Description

TECHNICAL AREA The present application relates generally to a post-treatment system, in particular to the detection of disturbances in the post-treatment system. STATE OF THE ART Internal combustion engines, such as diesel engines, emit exhaust gases containing nitrogen oxide (NOx) compounds. It is desirable to reduce NOx emissions, for example, to comply with environmental regulations. To reduce NOx emissions, a reducing agent can be metered into the exhaust gases via a dosing system in an aftertreatment system. The reducing agent interacts with a catalyst element, such as a selective catalytic reduction (SCR) catalyst, to facilitate the conversion of some of the NOx in the exhaust gas into non-NOx emissions such as nitrogen (N2), carbon dioxide (CO2), and water (H2O), thereby reducing NOx emissions. In some applications, exhaust gas compounds can also be reduced by one or more catalyst elements (e.g., a diesel oxidation catalyst (DOC), an ammonia oxidation catalyst (AMOx), etc.).) filtered or removed, which are located in a post-treatment system. SUMMARY In one embodiment, a post-treatment system comprises a first metering system, which includes a first metering unit, a first pressure sensor, and a first metering pump. The post-treatment system comprises a second metering system, which includes a second metering unit, a second pressure sensor, and a second metering pump. The post-treatment system includes a control unit. The control unit is configured to determine the fulfillment of one or more activation conditions. In response to the fulfillment of one or more activation conditions, the control unit is configured to feed reducing agent to a selective catalytic reduction (SCR) system using the first and second metering systems.The control unit is configured to determine, in response to dosing, a first pressure value connected to the first dosing system using the first pressure sensor, and a second pressure value connected to the second dosing system using the second pressure sensor. The control unit is configured to apply a target pressure override to the first doser for an initial period when the first and second pressure values ​​reach a first threshold. At the end of this initial period, after the target pressure override has been applied, the control unit is configured to determine a third pressure value connected to the first dosing system using the first pressure sensor and a fourth pressure value connected to the second dosing system using the second pressure sensor.The control unit is configured to determine the difference between the third and fourth pressure values. It is configured to compare this difference to a second threshold value. Based on this comparison, the control unit generates an indication of an electrical or mechanical fault in the first dosing system. In another embodiment, a post-treatment system comprises a first metering system comprising a first metering unit, a first pressure sensor, and a first metering pump. The post-treatment system comprises a second metering system comprising a second metering unit, a second pressure sensor, and a second metering pump. The post-treatment system includes a control unit. The control unit is configured to determine the fulfillment of one or more activation conditions. In response to the fulfillment of one or more activation conditions, the control unit is configured to prime the first metering pump while delaying the priming of the second metering pump for a first period.The control unit is configured to determine, in response to the priming of the first dosing pump for the first period and the subsequent delay in priming the second pump, a first pressure value associated with the first dosing system using the first pressure sensor, and a second pressure value associated with the second dosing system using the second pressure sensor. The control unit is configured to determine the difference between the first and second pressure values. The control unit is configured to compare this difference against a threshold value. Based on this comparison, the control unit generates an indication of an electrical or mechanical fault in the first dosing system. In another embodiment, a post-treatment system comprises a first metering system, which includes a first metering unit, a first pressure sensor, and a first metering pump. The post-treatment system comprises a second metering system, which includes a second metering unit, a second pressure sensor, and a second metering pump. The post-treatment system includes a control unit. The control unit is configured to determine whether one or more activation conditions have been met. In response to the fulfillment of one or more activation conditions, the control unit is configured to operate the first metering pump and the second metering pump for a first period. The control unit is configured to stop the operation of the first metering pump after the first period has elapsed, while the second metering pump continues to operate.The control unit is configured to determine, in response to the first dosing pump stopping operation, a first pressure value connected to the first dosing system using the first pressure sensor, and a second pressure value connected to the second dosing system using the second pressure sensor. The control unit is configured to determine the difference between the first and second pressure values. The control unit is configured to compare this difference to a threshold value. Based on this comparison, the control unit generates an indication of an electrical or mechanical fault in the first dosing system. In another embodiment, a post-treatment system comprises a first metering system, which includes a first metering unit, a first pressure sensor, and a first metering pump. The post-treatment system comprises a second metering system, which includes a second metering unit, a second pressure sensor, and a second metering pump. The post-treatment system includes a control unit. The control unit is configured to determine the fulfillment of one or more activation conditions. In response to the fulfillment of one or more activation conditions, the control unit is configured to operate the first metering pump and the second metering pump for a first period. After the first period has elapsed, the control unit determines a first duty cycle for the first metering pump and a second duty cycle for the second metering pump before a key cycle.The control unit is configured to determine a third duty cycle for the first metering pump and a fourth duty cycle for the second metering pump after the key cycle. The control unit is configured to determine a first difference between the first and third duty cycles. The control unit is configured to determine a second difference between the second and fourth duty cycles. The control unit is configured to compare the first and second differences against a threshold value. Based on this comparison, the control unit generates an indication of an electrical or mechanical fault in the first metering system. It should be noted that all combinations of the foregoing concepts and the additional concepts described in more detail below (provided these concepts are not incompatible with each other) shall be considered as part of the subject matter disclosed herein. In particular, all combinations of the claimed subject matter listed at the end of this disclosure shall be considered as part of the subject matter disclosed herein. BRIEF DESCRIPTION OF THE FIGURES The details of one or more embodiments are set forth in the accompanying drawings and the description below. Further features, aspects, and advantages of the disclosure will become apparent from the description, the drawings, and the claims, in which: Fig. 1 is a first example of a schematic diagram of an engine exhaust aftertreatment system coupled with a control unit; Fig. 2 is a second example of a schematic diagram of an engine exhaust aftertreatment system coupled with a control unit; Fig. 3 is an example graph showing the behavior of a healthy aftertreatment system during a pressure override in the aftertreatment system of Fig. 1 and / or Fig. 2; Fig. 4 is an example graph showing the behavior of an unhealthy aftertreatment system during a pressure override in the aftertreatment system of Fig. 1 and / or Fig. 2.Figure 5 is another example graph showing the behavior of an unhealthy post-treatment system during a pressure override in the post-treatment system of Figure 1 and / or Figure 2. Figure 6 is an example process flow diagram of a first method for detecting manipulations in the post-treatment system of Figure 1. Figure 7 is an example flow diagram of a diagnostic process overview of the method from Figure 6, executed by the control unit from Figure 1. Figures 8A-8C are an example process flow diagram of a method for performing example dosing manipulation detection according to Figure 7; Figure 9A is a first example graph showing the behavior of a healthy post-treatment system; Figure 9B is a first example graph showing the behavior of a post-treatment system with dosing manipulation; Figure 10A is a second example graph showing the behavior of a healthy post-treatment system; FigureFigure 10B is a second example graph showing the behavior of a post-treatment system with dosing manipulation. Figure 11 is an example process flow diagram of a second method for detecting manipulations in the post-treatment system of Figure 1 or Figure 2. Figure 12 is an example graph showing a first diagnostic case of the execution of the second method from Figure 11. Figure 13 is an example process flow diagram of a third method for detecting manipulations in the post-treatment system of Figure 1 or Figure 2. Figure 14 is an example graph showing a second diagnostic case of the execution of the third method from Figure 13. Figure 15 is an example process flow diagram of a fourth method for detecting manipulations in the post-treatment system of Figure 1 or Figure 2. Figures 16 and 17 are example graphs that represent a third diagnostic case of carrying out the fourth procedure from Figure 11. It should be noted that some or all of the figures are schematic representations for illustrative purposes. The figures serve to illustrate one or more embodiments, and it is expressly stated that they are not intended to limit the scope or meaning of the claims. DETAILED DESCRIPTION The following section describes various concepts and embodiments of methods and devices for detecting mechanical and / or electrical manipulations within a post-treatment system. The various concepts presented above and explained in more detail below can be implemented in different ways, as the described concepts are not limited to a specific implementation method. Examples of specific embodiments and applications serve primarily for illustrative purposes. Internal combustion engines (e.g., diesel engines, etc.) produce exhaust gases (hereinafter also referred to as exhaust). Depending on the fuel consumed by an internal combustion engine, the exhaust gases can contain various byproducts (e.g., NOx, carbon monoxide (CO), unburned hydrocarbons (HC), etc.). The exhaust gas byproducts can be measured or detected by one or more sensors of an aftertreatment system, for example, by measuring the density, volume, parts per million (ppm), etc., of the exhaust gas. The engine can be connected to an aftertreatment system, for example, via an exhaust pipe connected to the engine. Referring to the illustrations in general, the various embodiments disclosed herein relate to systems, devices, and methods for detecting electrical and / or mechanical manipulations within an aftertreatment system. Components in aftertreatment systems for reducing byproducts (e.g., NOx, soot, etc.) in exhaust gas include an SCR system, which reduces harmful NOx emissions in the exhaust gas in a two-stage process, or a DOC element, which filters or oxidizes hydrocarbons, carbon monoxide, or unburned fuel and oil. With regard to the SCR, a metering device first injects a reducing agent into the exhaust gas stream. This reducing agent may be urea, diesel exhaust fluid (DEF), AdBlue®, a urea-water solution (UWS), an aqueous urea solution (e.g., AUS32, etc.), or another similar liquid. The reducing agent may decompose to NH3 after injection.This mixture is then passed through an SCR catalyst element, which triggers a reaction at a specific temperature, converting the harmful NOx particles into pure nitrogen and water. During operation, any undecomposed reducing agent and unreacted ammonia can be stored in the catalyst element (e.g., the SCR catalyst element) to chemically react with the exhaust gas product (e.g., NOx particles, etc.). Exhaust gas byproducts can be reduced by one or more aftertreatment components of the aftertreatment system, such as a DOC element or an SCR catalyst element, among other types of catalysts. The aftertreatment system can include multiple dosing systems, each located in different legs of the aftertreatment system or in the same leg. For simplicity, the examples given here depict an aftertreatment system with two legs; however, the aftertreatment system can include more than two legs, each with components for reducing exhaust gas byproducts. For example, the exhaust gases can flow through or pass through the aftertreatment system via a first and a second leg. The catalyst element (e.g., SCR catalyst element, DOC element, etc.)Each leg of the aftertreatment system can facilitate chemical reactions of the byproducts and the reducing agent to reduce or minimize emissions from the engine system's exhaust pipe. For simplicity, the examples given herein can provide either the SCR catalyst element or the DOC element as the catalyst element of the aftertreatment system. Each leg of the aftertreatment system can be dosed with ammonia (NH3) (e.g., reducing agent) to reduce the exhaust byproduct. The dosing of the reducing agent can be based on NOx measurements (and / or other factors, such as the exhaust mass flow rate) from the NOx sensor of the respective leg. An aftertreatment system can comprise one or more metering systems, each including a metering unit, a pressure sensor, and a metering pump. The metering system can be used to dose reducing agent into an SCR system. In particular, the metering system can be used to ensure that the correct amount of reducing agent is supplied to the SCR system. In a metering system, the metering pump can be connected to a reducing agent source tank and is configured to supply reducing agent to a metering unit, which then injects the reducing agent into an SCR system. In some embodiments, each of the metering systems can include a control unit or electronic control module configured to receive information about the metering systems and control their operation. The metering system can also include a pressure sensor.The pressure sensor can provide pressure measurements to an electronic control unit (ECM) for the metering unit to help it accurately dose the reducing agent. In some examples, a post-treatment system can comprise two legs, each containing a metering system and an SCR system. For example, the first leg can include a first metering system (e.g., including a first metering pump, a first metering unit, a first pressure sensor, a first ECM, etc.) and a first SCR system, while the second leg can include a second metering system (e.g., including a second metering pump, a second metering unit, a second pressure sensor, a second ECM, etc.) and a second SCR system. In some embodiments, the post-treatment system can comprise multiple SCR systems connected in series, each containing metering pumps and metering units. In some cases, a user may mechanically manipulate or disrupt a dosing system within the post-treatment system. The user may manipulate or disrupt the dosing system by removing, incorrectly connecting, or otherwise moving one or more components of the dosing system. The user may also mechanically manipulate or disrupt the dosing system by physically connecting a first and second dosing unit to a single supply unit. In a healthy post-treatment system without any manipulation (neither mechanical nor electrical), each dosing unit is connected to its associated supply unit (e.g., the first dosing unit is connected to the first supply unit, and the second dosing unit is connected to the second supply unit). In other cases, a user may electrically manipulate the dosing system within the post-treatment system, for example, by creating an electrical connection between the pressure sensor for the first dosing system and the electronic control module for both dosing systems. In a healthy, unmodified post-treatment system, the first pressure sensor for the first dosing system would be electrically connected only to the first electronic control module for the first dosing system, while the second pressure sensor for the second dosing system would be electrically connected only to the second electronic control module for the second dosing system. However, in a manipulated system, the first pressure sensor of the first dosing system can be electrically connected to both the first and second electronic control modules.In these cases, it can be difficult to detect manipulation of the dosing system during the operation of the post-treatment system, as the sensor values ​​are still being recorded, which may lead to inaccurate reducing agent dosing within the post-treatment systems. The systems, methods, and devices described here are configured to detect such electrical and mechanical manipulations / disturbances of the dosing system. In some embodiments, the post-treatment system comprises one or more post-treatment system legs, multiple dosing systems within the one or more post-treatment system legs, and a control unit that may be configured to determine disturbances of the dosing system. The control unit comprises at least one processor coupled to at least one memory. For example, in a first embodiment, the control unit determines whether one or more activation conditions are met. In response to the fulfillment of one or more activation conditions, the control unit doses reducing agent into an SCR system using the first dosing system and the second dosing system.In response to the dosing, the control unit determines a first pressure value for the first dosing system and a second pressure value for the second dosing system. In some embodiments, the control unit can determine the first and second pressure values ​​by receiving pressure measurements from a first pressure sensor of the first dosing system and a second pressure sensor of the second dosing system. The control unit can then apply a target pressure override to the first doser for a first period when the first and second pressure values ​​reach a first threshold. At the end of the first period after the target pressure override has been applied, the control unit can determine a third pressure value for the first dosing system and a fourth pressure value for the second dosing system. The control unit can then determine the difference between the third and fourth pressure values.The control unit can then compare the difference with a second threshold. Based on this comparison, the control unit can generate an indication of an electrical or mechanical fault in the first dosing system. For example, if the difference exceeds the second threshold, the control unit can determine that no electrical or mechanical tampering has occurred. As a further example, in a second embodiment, the control unit determines the fulfillment of one or more activation conditions. In response to the fulfillment of one or more activation conditions, the control unit primes the first metering pump while delaying the priming of the second metering pump for a first period. After the first metering pump has been primed for the first period, while the priming of the second metering pump is delayed, the control unit determines a first pressure value for the first metering system and a second pressure value for the second metering system. In some embodiments, the control unit can determine the first and second pressure values ​​by receiving pressure measurements from a first pressure sensor of the first metering system and a second pressure sensor of the second metering system. The control unit can then determine the difference between the first and second pressure values.The control unit can then compare the difference with a threshold value. Based on this comparison, the control unit can generate an indication of an electrical or mechanical fault in the first dosing system. For example, if the difference exceeds the threshold value, the control unit can determine that no electrical or mechanical tampering has occurred. As a further example, in a third embodiment, the control unit determines the fulfillment of one or more activation conditions. In response to the fulfillment of one or more activation conditions, the control unit can operate the first metering pump and the second metering pump for a first period. After the first period has elapsed, the control unit stops the operation of the first metering pump while continuing the operation of the second metering pump. After the operation of the first metering pump has ceased, the control unit determines a first pressure value for the first metering system and a second pressure value for the second metering system. In some embodiments, the control unit can determine the first and second pressure values ​​by receiving pressure measurements from a first pressure sensor of the first metering system and a second pressure sensor of the second metering system.The control unit can then determine the difference between the first and second pressure readings. It can then compare this difference to a threshold value. Based on this comparison, the control unit can generate an indication of an electrical or mechanical fault in the first dosing system. For example, if the difference exceeds the threshold value, the control unit can determine that no electrical or mechanical tampering has occurred. As a further example, in a fourth embodiment, the control unit determines the fulfillment of one or more activation conditions. In response to the fulfillment of one or more activation conditions, the control unit can operate the first metering pump and the second metering pump for a first period. After the first period, the control unit can determine a first duty cycle for the first metering pump and a second duty cycle for the second metering pump before a key cycle. The control unit can determine a third duty cycle for the first metering pump and a fourth duty cycle for the second metering pump after the key cycle. The control unit can then determine a first difference between the first duty cycle and the third duty cycle. The control unit can then determine a second difference between the second duty cycle and the fourth duty cycle.The control unit is configured to compare the first and second differences against a threshold value. Based on this comparison, the control unit generates an indication of an electrical or mechanical fault in the first dosing system. For example, if both the first and second differences exceed the threshold value, the control unit may determine that no mechanical or electrical fault is present. The systems and methods described here offer the advantage of providing a mechanism for detecting mechanical and electrical tampering or malfunctions within an aftertreatment system, thereby ensuring the accuracy of the reducing agent supplied to the system. This accuracy enables vehicles to filter NOx from exhaust gases more efficiently, which can be highly desirable. These features enable the embodiments described here to detect tampering with the pressure sensor and / or the dosing system within the aftertreatment system, allowing the operator and / or service technician to be notified in order to rectify the mechanical or electrical manipulation. Consequently, the embodiments described here are able to reduce the NOx slip caused by system manipulations downstream of the SCR system and bring the aftertreatment system into compliance with environmental regulations. With reference to Fig. 1, a schematic diagram of a system 10 with a control unit 100 according to a first embodiment is shown. The system 10 comprises an internal combustion engine 20 (hereinafter referred to as the "engine") coupled to an exhaust aftertreatment system 22, which is in exhaust communication with the engine. As shown, the exhaust aftertreatment system 22 consists of several legs (e.g., a first leg 22A and a second leg 22B), each leg comprising respective components of the exhaust aftertreatment system 22. Although two legs are shown and described here for the purposes of the examples, the exhaust aftertreatment system 22 may comprise more or fewer than two legs, consisting of additional component(s) of the exhaust aftertreatment system 22. The controller 100 is coupled to or communicated with the system 10 together with an operator input / output (I / O) device 120.System 10 can be integrated into a vehicle. The vehicle can be a road or off-road vehicle, including but not limited to long-haul trucks, medium-haul trucks (e.g., pickup trucks), cars, boats, tanks, aircraft, locomotives, mining equipment, and any other type of vehicle. The vehicle can include a transmission, a fuel system, one or more additional vehicle subsystems, etc. In this respect, the vehicle can include additional, fewer, and / or different components / systems, such that the principles, methods, systems, devices, processes, and the like of this disclosure are intended to be applicable to any other vehicle configuration. It should also be understood that the principles of this disclosure should not be interpreted as being limited to vehicles; rather, this disclosure is also applicable to stationary equipment such as power generators or power units. The engine 20 can be a compression-ignition internal combustion engine that uses diesel fuel. In various other embodiments, the engine 20 can be constructed like any other type of engine (e.g., spark-ignition) that uses any type of fuel (e.g., gasoline, natural gas, etc.). In some embodiments, the vehicle can be a different type of vehicle, for example, a hybrid vehicle with one or more electric motors, a fuel cell vehicle, etc. Although the engine 20 is presented here as a diesel-powered internal combustion engine, other embodiments also fall within the scope of this disclosure. Inside the internal combustion engine 20, air from the atmosphere is mixed with fuel and burned to power the engine. The combustion of fuel and air in the compression chambers of the engine 20 produces exhaust gases, which are functionally routed to an exhaust manifold (not shown) and to the exhaust aftertreatment system 22. Each of the legs (e.g., the first leg 22A and the second leg 22B) of the exhaust aftertreatment system 22 comprises a diesel oxidation catalyst element (DOC) 30, a diesel particulate filter element (DPF) 40, a metering system 52, a selective catalytic reduction catalyst element (SCR) 50, and an ammonia oxidation catalyst element (AMOx) 60. The first leg 22A comprises the DOC element 30A, the DPF element 40A, a first metering system 52A, a first SCR catalyst element 50A, and the AMOx catalyst element 60A. The second leg 22B includes the DOC element 30B, the DPF element 40B, the dosing system 52B, a second SCR catalyst element 50B and the AMOx catalyst element 60B.For the sake of simplicity, the components of the respective legs described here can be referred to generally, for example as DOC element 30, DPF element 40, dosing system 52 with a corresponding SCR catalyst element 50 and AMOx catalyst element 60, which are assigned to the respective first leg 22A or the second leg 22B. The exhaust aftertreatment system 22 further comprises an exhaust gas recirculation (EGR) system 70. The metering systems 52A, 52B of the respective legs comprise reducing agent delivery systems which have reducing agent sources 54A, 54B (e.g., reducing agent sources 54A, 54B of the legs) that supply reducing agent to the metering units 56A-B (e.g., referred to here generally as metering units 56 for the first leg 22A and the second leg 22B) via reducing agent delivery lines 58A-B. The metering systems 52A, 52B may also include pressure sensors 16 and a metering pump (not shown). In the exhaust flow direction indicated by the direction arrow 29, the exhaust gas flows from the engine 20 into the inlet line 24 of the exhaust aftertreatment system 22. From the inlet line 24, the exhaust gas flows in the first leg 22A into the DOC element 30 and exits from the DOC element 30 into a first section of the exhaust line 28A. From the first section of the exhaust line 28A, the exhaust gas flows into the DPF element 40 and exits from the DPF element 40 into a second section of the exhaust line 28B. From the second section of the exhaust line 28B, the exhaust gas flows into the SCR catalyst element 50 and exits from the SCR catalyst element 50 into the third section of the exhaust line 28C. As the exhaust gas flows through the second section of the exhaust line 28B, it is periodically mixed with reducing agent by the dosing unit 56B.Accordingly, the second section of the exhaust line 28B functions as a decomposition chamber or pipe to facilitate the decomposition of the reducing agent to ammonia. From the third section of the exhaust line 28C, the exhaust gas flows into the AMOx catalyst element 60 and exits from the AMOx catalyst element 60 into the exhaust line 26 before being expelled from the exhaust aftertreatment system 22. Similarly, in the second leg 22B, the exhaust gas flows through the pipes 28D-28F, passes through the various components in the second leg 22B, and enters the exhaust line 26. Based on the foregoing, in the illustrated embodiment, the DOC element 30 (e.g., DOC element 30A or DOC element 30B) is positioned upstream of the DPF element 40 (e.g., DPF element 40A or DPF element 40B) and the SCR catalyst element 50 (e.g., SCR catalyst element 50A or SCR catalyst element 50B), and the SCR catalyst element 50 (e.g., SCR catalyst element 50A or SCR catalyst element 50B) is positioned downstream of the DPF element 40 (e.g., DPF element 40A or DPF element 40B) and upstream of the AMOx catalyst element 60 (e.g., AMOx catalyst element 60A or The AMOx catalyst element 60B is positioned. However, in alternative embodiments, other arrangements of the components of the exhaust aftertreatment system 22 are also possible. For simplification, the components of one leg in the exhaust aftertreatment system 22 can be similar to those of another leg.Alternatively, one or more components or the arrangement of the components in the first leg 22A may differ from those in the second leg 22B, etc. The DOC element 30 can be designed to have any number of different flow patterns. The DOC element 30 can be designed to oxidize at least some of the particles in the exhaust gas (e.g., the soluble organic fraction of soot) and to reduce unburned hydrocarbons and CO in the exhaust gas to less harmful compounds. For example, the DOC element 30 can be designed to reduce the hydrocarbon and CO concentrations in the exhaust gas to meet the required emission standards for these exhaust gas components. An indirect consequence of the oxidizing capabilities of the DOC element 30 is its ability to oxidize NO to NO₂. In this way, the NO₂ content leaving the DOC element 30 corresponds to the NO₂ content in the exhaust gases produced by the engine 20, in addition to the NO₂ converted from NO by the DOC element 30. In addition to treating hydrocarbon and CO concentrations in the exhaust gas, the DOC element 30 can also be used for the controlled regeneration of the DPF element 40, the SCR catalyst element 50, and the AMOx catalyst element 60. This can be achieved by injecting or dosing unburned HC into the exhaust gas upstream of the DOC element 30. Upon contact with the DOC element 30, the unburned HC undergoes an exothermic oxidation reaction, leading to an increase in the temperature of the exhaust gases exiting the DOC element 30 and subsequently entering the DPF element 40, the SCR catalyst element 50, and / or the AMOx catalyst element 60. The amount of unburned HC added to the exhaust gas is selected to achieve the desired temperature increase or the target controlled regeneration temperature. The DPF element 40 can have any flow-through design and is engineered to reduce the particle concentration (e.g., soot and ash) in the exhaust gas to meet the required emission standards. The DPF element 40 captures particles and other components and can therefore be regularly regenerated to burn off the captured components. Additionally, the DPF element 40 can be designed to oxidize NO to NO₂ independently of the DOC element 30. As explained above, each of the metering systems 52A, 52B includes a reducing agent delivery system. The reducing agent delivery system comprises a reducing agent source 54A, 54B, a metering pump 53A, 53B, and a metering unit 56. The reducing agent source 54 can be a container or tank capable of retaining a reducing agent. The reducing agent source 54 communicates with the metering pump 53A, 53B, which is designed to pump reducing agent from the reducing agent source 54 via a reducing agent delivery line 58 to the metering unit 56. The metering pumps 53A, 53B can be configured to pressurize the reducing agent from the reducing agent source 54 to deliver it to the metering units 56A, 56B. The metering unit 56 is positioned upstream of the SCR catalyst element 50. The dosing unit 56 is selectively controllable to inject reducing agent directly into the exhaust gas stream before it enters the SCR catalyst element 50.As described herein, the control unit 100 is designed to control the timing and quantity of the reducing agent added to the exhaust gas, for example, based on the NOx quantity measured by the NOx sensor 12 upstream of the dosing system 52 or the pressure measured by the pressure sensor 16 upstream of the dosing system 52. The reducing agent can decompose and form ammonia. As briefly described above, in the presence of the SCR catalyst element 50, the ammonia reacts with NOx to reduce the NOx to less harmful emissions such as N2 and H2O. The NOx in the exhaust gas stream comprises NO2 and NO. Both NO2 and NO are reduced to N2 and H2O by various chemical reactions triggered by the catalytic elements of the SCR catalyst element in the presence of NH3. In some embodiments, the control unit 100 is configured to control the metering device 56 for supplying the reducing agent to be used in the post-treatment system 22. In some other examples, the post-treatment system 22 may include NOx sensors 12 upstream of the DOC elements 30 of the legs, and the NOx measurements of these NOx sensors 12 may be used to determine the ANR associated with the respective legs. In some other examples, the post-treatment system 22 may include pressure sensors upstream of the metering systems 52 of the legs, and the pressure measurements of the pressure sensors 16 may be used to ensure that the metering of the reducing agent is accurate. In some embodiments, the SCR catalyst element 50 is a vanadium-based catalyst element, and in other embodiments, the SCR catalyst element is a zeolite-based catalyst element, such as a copper-zeolite (Cu-Ze) or iron-zeolite (Fe-Zu) catalyst element. In one representative embodiment, the reducing agent is aqueous urea, and the SCR catalyst element 50 is a zeolite-based catalyst element. In other embodiments, the reducing agent comprises a first reducing agent and a second reducing agent, wherein the first reducing agent is urea and the second reducing agent is ammonia. The AMOx catalyst element 60 can be one of several flow-through catalyst elements designed to react with ammonia to primarily produce nitrogen. As briefly described above, the AMOx catalyst element 60 is designed to remove ammonia that has passed through or exited the SCR catalyst element 50 without reacting with NOx in the exhaust gas. In certain cases, the aftertreatment system 22 can be operated with or without the AMOx catalyst element 60. Although the AMOx catalyst element 60 is shown in Fig. 1 as a separate unit from the metering system 52, in some embodiments the AMOx catalyst element can be integrated into the SCR catalyst element (e.g., the AMOx catalyst element and the SCR catalyst element can be housed in the same casing). As mentioned herein, the SCR catalyst element 50 and the AMOx catalyst element 60 form the SCR and AMOx system. System 10 (e.g., aftertreatment system 22) comprises various sensors. For example, aftertreatment system 22 includes NOx sensors 12. Aftertreatment system 22 includes temperature sensors 14. Aftertreatment system 22 includes pressure sensors 16. The sensors can be strategically positioned throughout aftertreatment system 22, for example, upstream, at, or downstream of one or more catalysts (e.g., DOC element 30, DPF element 40, SCR catalyst element 50, and / or AMOx catalyst element 60). The sensors can communicate with the control unit 100 and be configured to monitor the operating conditions of system 10. It should be noted that one or more NOx, pressure, temperature, and various other sensors (oxygen sensors, exhaust component sensors, NH3 sensors) can also be integrated into the system and positioned at different locations. The temperature sensors 14 are connected to one or more catalyst elements. The temperature sensors 14 are strategically positioned to measure the temperature of the exhaust gas flowing into the DOC element 30 (e.g., the temperature of the exhaust gas line upstream of the catalyst element), out of the DOC element 30 (e.g., the temperature of the exhaust gas line downstream of the catalyst element), into another catalyst element (e.g., from the DOC element 30 to the DPF element 40), and out of the DPF element 40 before it is metered with reducing agent by the metering device 56. In some embodiments, at least one temperature sensor 14 can be configured as part of the catalyst element itself, thereby directly measuring the bed temperature of the catalyst element. The EGR system 70 is designed to redirect exhaust gases back to an intake manifold of the engine 20, where they are used for combustion. The EGR system 70 comprises an EGR cooler 74 and an EGR valve 76. The EGR cooler 74 can, for example, be an air-to-air and / or liquid-to-air heat exchanger (e.g., coolant-exhaust) in some applications. The EGR cooler 74 is designed to remove heat from the exhaust gases before they are recirculated into the intake manifold. Heat is removed from the exhaust gas before it is reintroduced, among other reasons, to prevent high intake temperatures that could promote pre-ignition (e.g., engine knocking). Although the exhaust aftertreatment system 22 shown comprises the DOC element 30, the DPF element 40, the SCR catalyst element 50 and the AMOx catalyst element 60, which are arranged at specific locations relative to each other along the exhaust flow path, in other embodiments they can be arranged at any positions relative to each other along the exhaust flow path, and the exhaust aftertreatment system can comprise more than one of the elements DOC element 30, DPF element 40, SCR catalyst element 50 and AMOx catalyst element 60. Figure 1 is also shown to include an operator input / output (I / O) device 120. The operator I / O device 120 is connected to the control unit 100 so that information can be exchanged between the control unit 100 and the I / O device 120. The information exchanged between the control unit 100 and the I / O device 120 may relate to one or more components from Figure 1 or to one of the provisions of the control unit 100 disclosed herein. The operator I / O device 120 enables an operator (e.g., occupant, etc.) of the vehicle to communicate with the control unit 100 and other components of the vehicle, such as those shown in Figure 1. The operator I / O device 120 may, for example, include an interactive display, a touchscreen device, one or more buttons and switches, voice command receivers, etc.In some cases, the I / O device 120 can be part of a vehicle, including the engine 20 and the aftertreatment system 22. In other cases, the I / O device 120 can be a remote device that the operator can access, for example, via a customer device. In some aspects, the I / O device 120 can be a server that receives data from the vehicle's control unit 100. The control unit 100 is designed to monitor the processes, states, or events within the system 10 (e.g., components of the aftertreatment system 22). The control unit 100 is configured to at least partially control the operation of the system 10 and its associated subsystems, such as the combustion engine 20 and the exhaust aftertreatment system 22. Communication between the components can occur via any number of wired or wireless connections. A wired connection can include, for example, a serial cable, a fiber optic cable, a CAT5 cable, or any other type of wired connection. In contrast, a wireless connection can include the internet, WLAN, cellular networks, radio, Bluetooth, etc. In one embodiment, a Controller Area Network (“CAN”) bus enables the exchange of signals, information, and / or data.The CAN bus comprises any number of wired and wireless connections. Since the control unit 100 is communicatively coupled with the systems and components of Fig. 1, the control unit 100 is configured to receive data from one or more of the components shown in Fig. 1. For example, the data can include NOx data (e.g., an incoming NOx quantity from the NOx sensor 12 upstream of the DOC element 30 or SCR catalyst element 50 and an outgoing NOx quantity from the NOx sensor 12 downstream of the SCR catalyst element 50), dosing data (e.g., time and quantity of the dose dispensed by the dosing unit 56, dosing pump speed, etc.), pressure data, and vehicle operating data (e.g., engine speed, vehicle speed, engine temperature, flow rate, etc.) received via one or more sensors. As another example, the data could include an input from the operator input / output device 120.As described in more detail herein, the control unit 100 uses this data to monitor the multi-stage aftertreatment system 22 in order to determine whether the NOx sensor 12 has been moved from one leg to another (e.g., the user has tampered with at least one NOx sensor 12) and to detect the misplacement of the NOx sensor 12 in order to minimize, for example, the reducing agent slip or NOx slip due to an incorrect calculation of the conversion efficiency or measurement of the NOx content downstream of the SCR catalyst element 50. The Control Unit 100 comprises a processing circuit with a processor, memory, and various circuits configured to perform the features, functions, or operations described 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 group of processing components, or other suitable electronic processing components. The memory (e.g., RAM, ROM, flash memory, hard disk memory, etc.) may store data and / or computer code to facilitate the various processes described herein. The memory may be interconnected with 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 herein with respect to the Control Unit 100.Furthermore, the storage can be or include tangible, non-temporary volatile storage or non-volatile storage. Accordingly, the storage can contain database components, object code components, script components, or any other type of information structure to support the various activities and information structures described here. The control unit 100 includes a communication interface. This interface can comprise any combination of wired and / or wireless interfaces (e.g., sockets, antennas, transmitters, receivers, transceivers, cable connections) to enable data communication with various systems, devices, or networks. These interfaces are structured to facilitate communication both within the vehicle (e.g., between vehicle components) and outside the vehicle (e.g., directly with a remote computer). In some embodiments, the communication interface also includes a network interface. This network interface is used to establish connections to other devices via a network. The network interface includes program logic that facilitates the connection of the control unit 100 to the network.The network interface comprises any combination of a wireless network transceiver (e.g., a cellular modem, a Bluetooth transceiver, a Wi-Fi transceiver) and / or a wired network transceiver (e.g., an Ethernet transceiver). In some configurations, the network interface includes the hardware and machine-readable media required to support communication over multiple data communication channels. Furthermore, in some configurations, the network interface includes cryptographic capabilities to establish a secure or relatively secure communication session, in which the data transmitted over the session is encrypted.For example, the communication interface for communication outside the vehicle / system may include an Ethernet card and a port for sending and receiving data over an Ethernet-based communication network and / or a Wi-Fi transceiver for communication over a wireless communication network. The communication interface may be structured to communicate over local area networks and / or wide area networks (e.g., the internet), and it may use a variety of communication protocols (e.g., IP, LON, Bluetooth, ZigBee, as well as radio, cellular, and near-field communication). Furthermore, the communication interface may operate in conjunction with, or in parallel with, a telematics unit, if one is included, to communicate with other vehicles in the fleet and / or the remote computer system. The control unit 100 is designed to receive inputs (e.g., signals, information, data, etc.) from the components / systems of system 10 and / or the operator I / O device 120. Thus, the control unit 100 is designed to at least partially control the components / systems of system 10 and the associated motor 20. Since the components from Fig. 1 can be embodied in an embodiment of a vehicle, the control unit 100 can be configured as one or more electronic control units (ECUs). The control unit 100 can be separate from or integrated into at least one of the following units: a transmission control unit, an exhaust aftertreatment unit, a powertrain control module, an engine control module, etc.In some cases, the control unit 100 may be a device located remote from the vehicle, for example a remote control, configured to control or communicate with one or more components of the system 10. With reference to Fig. 2, another schematic diagram of a system 80 with a control unit 100 according to a second embodiment is shown. The schematic diagram of system 10 shown in Fig. 2 is similar to that shown in Fig. 1 and includes many of the elements described above with reference to Fig. 1. However, Fig. 2 shows an embodiment in which the aftertreatment system 22 comprises only one leg (e.g., the first leg 22A), whereas Fig. 1 shows an embodiment in which the aftertreatment system 22 comprises several legs (e.g., the first leg 22A and the second leg 22B). Although the aftertreatment system 22 is shown with only a single leg in Fig. 2, it nevertheless includes several metering systems 52A, 52B and SCR catalyst elements 50, which are described in more detail above. With reference to Fig. 3, an example graph 300 is shown, illustrating the behavior of a healthy post-treatment system in the post-treatment system 22 from Fig. 1 and / or Fig. 2 according to an exemplary embodiment. A healthy post-treatment system is neither electrically nor mechanically manipulated (e.g., the sensors connected to each metering system are not moved to a different leg, the metering pumps connected to each metering unit are not moved to a different metering unit, etc.). Graph 300 shows pressure readings on the Y-axis 314 from the pressure sensor 16 during various scenarios. In particular, graph 300 shows a curve 302 to determine whether the first metering system is healthy and a curve 304 to determine whether the second metering system is healthy.The data shown in Graph 300 can be measured or acquired by various components of the system 10; for example, the data can be measured by the sensor of the post-treatment system 22. In some embodiments, a healthy post-treatment system can be metered to raise the pressure in the post-treatment system to a specific stable target pressure before a target pressure override 316 is applied to the post-treatment system 22. In Fig. 3, for example, the target pressure is set to 850 kPa. However, the target pressure can be set to any value (e.g., 600 kPa, 750 kPa, 800 kPa, 950 kPa, etc.). Once the stable target pressure is reached, the target pressure override can be applied to one of the metering devices 56A, 56B in the post-treatment system 22, and the response of both metering devices 56A, 56B is monitored.For example, in field 302, when the pressure override is applied to the first dispenser 56A, as shown by line 306 (e.g., the target pressure for the first leg 22A is increased to 950 kPa for a certain period), the target pressure for the second dispenser 56B remains unchanged (e.g., 850 kPa), as shown by line 308. After the target pressure override is applied, the control unit 100 determines that the pressure values ​​increase to the pressure specified by the target pressure override in the first dispenser 56A, while the pressure values ​​do not increase to the pressure specified by the target pressure override in the second dispenser 56B, because the target pressure override was only applied to one dispenser. This indicates a healthy post-treatment system. In curve 304, when the pressure override is applied to the second dispenser 56B, shown by line 310 (e.g.,The target pressure for the second dispenser 56A is increased to 950 kPa for a specific period. The target pressure for the first dispenser 56A remains unchanged (e.g., 850 kPa), as shown by line 312. After the target pressure overrun has been applied, the control unit 100 determines that the pressure values ​​in the second dispenser 56B increase, while the pressure values ​​in the first dispenser 56A do not increase. In some embodiments, the control unit 100 can measure the difference between the pressure measurements in the first dispenser 56A and the second dispenser 56B to determine whether tampering has occurred. For example, if the pressure difference is above a certain threshold (i.e., the pressure difference is large enough), the control unit 100 can determine that no tampering has occurred in the post-treatment system 22. Conversely, if the pressure difference is below a certain threshold (i.e., the pressure difference is not large enough), the control unit 100 can determine that tampering has occurred within the post-treatment system 22. The pressure values ​​in Graph 300 show a healthy post-treatment system that has not been tampered with, since the difference between the pressure values ​​in the first leg 22A and the second leg 22B is above a certain threshold. With reference to Fig. 4, an example graph 400 is shown, illustrating the behavior of an unhealthy post-treatment system during a pressure override in the post-treatment system 22 from Fig. 1 and / or Fig. 2. An unhealthy post-treatment system has been electrically or mechanically manipulated (e.g., the pressure sensor has been moved). The data shown in graph 400 can be measured or determined by various components of the system 10 or 80; for example, the data can be measured by the sensor of the post-treatment system 22. Similar to graph 300, graph 400 shows the pressure readings of the pressure sensor 16 during various scenarios on the Y-axis 414. In particular, graph 400 shows a curve 402 to determine whether the first dosing system 56A is unhealthy and a curve 404 to determine whether the second dosing system 56B is unhealthy.In some embodiments, a post-treatment system is pre-filled and metered to raise the pressure in the post-treatment system to a specific stable target pressure before a target pressure override 416 is applied to the post-treatment system 22. In Fig. 4, for example, the target pressure is set to 850 kPa. Once the stable target pressure is reached, the target pressure override can be applied to one of the metering devices 56A, 56B in the post-treatment system, and the response of both metering devices 56A, 56B is monitored. For example, in Diagram 402, the pressure override is applied to the first metering device 56A, as shown by line 406 (i.e., the target pressure for the first metering device 56A is increased to 950 kPa for a specific period). The target pressure for the second metering device 56B should remain the same (e.g., 850 kPa) because the target pressure override is applied only to the first metering device 56A.After the target pressure is applied, the control unit 100 determines that the pressure values ​​in the first feeder 56A increase, while the pressure values ​​in the second feeder 56B also increase, as shown in line 408. This indicates that the post-treatment system is malfunctioning. At point 404, when the pressure override is applied to the second feeder 56B (e.g., the target pressure for the second feeder 56B is increased to 950 kPa for a certain period), the control unit 100 determines that the pressure values ​​do not increase in either the second feeder 56B in line 412 or the first feeder 56A in line 410. The pressure values ​​shown in Graph 400 indicate an unhealthy (e.g. manipulated) post-treatment system that has been tampered with, as the difference between the pressure values ​​in the first dosing unit 56A and the second dosing unit 56B does not exceed a certain threshold. With reference to Fig. 5, an example graph 500 is shown, illustrating the behavior of an unhealthy post-treatment system during a pressure override in the post-treatment system 22 from Fig. 1 and / or Fig. 2. An unhealthy post-treatment system, as shown in graph 500, has been electrically or mechanically manipulated (e.g., the metering pump is incorrectly positioned). The data shown in graph 500 can be measured or determined by various components of the system 10 or 80; for example, the data can be measured by the sensor of the post-treatment system 22. Similar to graph 300, graph 500 shows the pressure readings of the pressure sensor 16 on the Y-axis 514. In particular, graph 500 shows a curve 502 to determine whether the first metering system 56A is unhealthy and a curve 504 to determine whether the second metering system 56B is unhealthy.In some embodiments, a post-treatment system is pre-filled and metered to raise the pressure in the post-treatment system to a specific stable target pressure before a target pressure override 516 is applied to the post-treatment system 22. In Fig. 5, for example, the target pressure is set to 850 kPa. Once the stable target pressure is reached, the target pressure override can be applied to one of the metering devices 56A, 56B in the post-treatment system, and the response of both metering devices 56A, 56B is monitored. For example, in curve 502, the pressure override is applied to the first metering device 56A, as shown by line 506 (e.g., the target pressure for the first metering device 56A is increased to 950 kPa for a specific period). The target pressure for the second dispenser 56B should remain unchanged in line 508 (e.g. 850 kPa), as the target pressure override is only applied to the first dispenser 56A.After the target pressure is applied, the control unit 100 determines that the pressure values ​​in the first dispenser 56A increase, while the pressure values ​​in the second dispenser 56B also increase. This indicates that the post-treatment system is malfunctioning. At 504, when pressure override is applied to the second dispenser 56B (e.g., the target pressure for the second dispenser 56B is increased to 950 kPa for a certain period), the control unit 100 determines that the pressure values ​​do not increase in either the second dispenser 56B at line 512 or the first dispenser 56A at line 510. In some embodiments, the pressure values ​​between the first and second legs may exhibit an initial pressure difference, as shown in graph 500. In such a case, the pressure difference between the first and second legs may need to exceed a certain threshold and the initial pressure difference observed between the first and second legs.The pressure values ​​shown in Graph 500 indicate an unhealthy (e.g. manipulated) post-treatment system that has been tampered with, as the difference between the pressure values ​​in the first dispenser 56A and the second dispenser 56B, taking into account the initial pressure difference, does not exceed a certain threshold. With reference to Fig. 6, an example process flow diagram of a method 600 for detecting mechanical or electrical manipulations in the post-treatment system of Fig. 1 and / or Fig. 2 is shown according to an exemplary embodiment. The processes, operations, or steps of the method 600 can be performed, operated, or executed by the components (e.g., control unit 100, I / O device 120, post-treatment system 22, sensors, etc.) of the system 10, the data processing system, the cloud computing environment, or other devices described herein in connection with Figs. 1-5. For example, additional or alternative operations of the method 600 can be performed by one or more circuits of the control unit 100. Additionally or alternatively, some operations of the method 600 can be performed by a remote device, for example, a remote data processing system.The process is described here in relation to the detection of a malfunction or tampering within the first dosing system 56A. However, this is not to be understood as a limitation. The procedures can also be applied to detect malfunctions or tampering within the second dosing system 56B or other dosing systems within the post-treatment system. In step 602, the control unit 100 is configured to determine whether one or more activation conditions have been met. One or more activation conditions may be met if the bed temperature of the SCR catalyst element 50 of the first leg 22A or the second leg 22B is greater than or equal to a predetermined threshold. One or more activation conditions may also be met if the control unit 100 determines that the metering system is ready for dosing. In particular, the control unit may determine that the metering system is ready for dosing if the metering pump has been primed and if the pressure within the first leg 22A and / or the second leg 22B is above a certain threshold. One or more activation conditions may include the control unit 100 determining that no other system continuity faults are present in the system.For example, if there is a fault in the pressure sensor or the metering pump in the aftertreatment system 22, the control unit 100 may not be able to use these components to diagnose the aftertreatment system 22 and determine whether a manipulation has occurred, because the other faults could interfere with such a diagnosis. One or more activation conditions may include the control unit 100 determining that no other diagnostic processes are to be performed. For example, if one or more system components (e.g., the pressure sensor 16, etc.) are being used to perform another diagnostic procedure, the control unit 100 may not be able to use these components to diagnose the aftertreatment system 22, because the other diagnostic processes could interfere with such a diagnosis, as the diagnostic process itself might affect the sensors. In step 604, the control unit 100 is configured to supply reducing agent to the SCR catalyst element 50A using either the first dosing system 52A or the second dosing system 52B. The control unit 100 begins dosing the reducing agent as soon as one or more activation conditions are met. The control unit 100 instructs the first dosing unit 56A to dose reducing agent to the first SCR catalyst element 50A. The control unit 100 instructs a second dosing unit 56B of the second leg 22B to dose reducing agent to the second SCR catalyst element 50B. In some embodiments, the initial reducing agent dosing process is performed before the one or more activation conditions are considered. For example, after the engine 20 is started, the control unit 100 can instruct the metering units 56 to dose reducing agent to the first SCR catalyst element 50A and the second SCR catalyst element 50B. The control unit 100 then determines whether the one or more activation conditions are met before proceeding, for example, to step 606. In step 606, the control unit is configured to determine, in response to the reducing agent dosing in step 604, a first pressure value connected to the first dosing system 52A and a second pressure value connected to the second dosing system 52B. The control unit 100 determines the first pressure value based on a reading or measurement from the first pressure sensor (e.g., pressure sensor 16, which is connected to or intended to measure the pressure of the first leg 22A). The control unit 100 determines the second pressure value based on a reading from the second pressure sensor (e.g., pressure sensor 16, which is connected to or intended to measure the pressure of the second leg 22B). These pressure values ​​measured in step 606 are used to determine the steady-state pressure values ​​of the first and second SCRs.For example, the control unit 100 detects that the readings from the first and second pressure sensors have been within a predefined standard deviation (e.g., 2%, 3%, etc.) for at least a predefined period of time. If the pressure sensor readings are within the predefined standard deviation, the control unit 100 aggregates the pressure sensor readings (e.g., average, mean, median, etc.) for each leg. Based on the aggregated pressure sensor readings, the control unit 100 determines, for example, the first pressure value and the second pressure value. The control unit 100 is configured to store the first and second pressure values ​​in order to compare them to a threshold value and determine whether the pressure in the aftertreatment system 22 has reached a certain equilibrium value before attempting to determine whether any manipulation has occurred in the system.In some embodiments, the control unit 100 determines whether the first and second pressure values ​​reach a first threshold. The predetermined threshold can indicate steady state. In some embodiments, the predetermined threshold can be a standard deviation in each of the first and second pressure values ​​measured in step 606 from previously determined pressure values ​​at the first SCR and the second SCR, respectively, or from specific pressure values ​​over a predetermined period (e.g., 2 minutes). The control unit 100 proceeds to step 608 if the first and second pressure values ​​reach the predetermined threshold. In step 608, the control unit 100 is configured to apply a target pressure override to the first dispenser 56A of the first dosing system 52A when the first pressure value and the second pressure value reach the first threshold value. In some embodiments, the control unit 100 applies the target pressure override to increase the target pressure for the dosing system 52 by a specific predetermined amount relative to the steady-state pressure (e.g., 100 kPa, 150 kPa, etc.) for a specific period of time (e.g., 10 seconds, 20 seconds, etc.). In other embodiments, the control unit 100 applies the target pressure override to decrease the target pressure for the dosing system 52 by a specific predetermined amount relative to the steady-state pressure for a specific period of time. In some cases, the period for applying the target pressure override can be predefined. In other cases, the period is based on the time required for the initial pressure value to change by a predetermined percentage or amount, e.g., 5%, 10%, 15%, 20%, etc. In some embodiments, the predetermined percentage can be based on the trial. In this case, the control unit 100 configures or sets a relatively lower percentage (e.g., 5%) on the first tamper detection trial than on a second trial (e.g., 10%, 15%, etc.). In step 610, the control unit 100 is configured to determine a third and a fourth pressure value. For example, at the end of another period (e.g., a second period that differs from the first) after applying the target pressure override to the first dispenser 56A, the control unit 100 measures a third pressure value connected to the first dispenser 52A, according to the reading of the first pressure sensor, and measures a fourth pressure value of the second dispenser 52B, according to the reading of the second pressure sensor. The second period can be an extension of the first period. The second period is used to allow the pressure in the first dispenser 52A to increase until it reaches the target pressure override value determined in step 608. In some embodiments, the third and fourth pressure values ​​may represent the highest pressure values ​​measured by the first and second pressure sensors during the period(s) (e.g., the first and / or second period). In some cases, the third and fourth pressure values ​​may represent an average, mean, median, etc., of the measurements taken during the period(s). In step 612, the control unit 100 is configured to determine the differences between the third and fourth pressure readings. As mentioned above, the control unit 100 can measure the difference between the pressure measurements in the first leg 22A and the second leg 22B to determine if tampering has occurred. In step 614, the control unit 100 is configured to compare the difference between the third and fourth pressure values ​​with a second threshold. If the pressure difference is above the second threshold, the control unit 100 can determine that no manipulation has occurred in the post-treatment system 22. Conversely, if the pressure difference is below the second threshold, the control unit 100 can determine that manipulation has occurred within the post-treatment system 22. The predetermined threshold can indicate a sufficiently large difference between the pressure values ​​to show that the pressure values ​​are not correlated (e.g., if the pressure value in the first leg 22A increases, the pressure value in the second leg 22B also increases).In step 616, the control unit 100 is configured to generate an indication of a mechanical or electrical fault within the first dosing system 52A or the second dosing system 52B, based on the comparison carried out in step 614. With reference to Fig. 7, an example flowchart for a diagnostic procedure 700 is now shown, which is executed by the control unit 100 from Fig. 1 and / or Fig. 2 according to an exemplary embodiment. The steps of the diagnostic procedure 700 can be performed by the components (e.g., control unit 100, I / O device 120, post-treatment system 22, sensors, etc.) of the system 10, the data processing system, the cloud computing environment, or other devices described herein in connection with Fig. 1. For example, additional or alternative operations of the procedure 700 can be performed by one or more circuits of the control unit 100. Additionally or alternatively, some operations of the procedure 700 can be performed by a remote device, for example, a remote data processing system.Some steps of the procedure 700 may involve the control unit 100 receiving data from components of the post-treatment system 22, such as one or more sensors, and forwarding the data to the remote device for processing, or vice versa. In step 702, the control unit 100 determines whether one or more activation conditions are met. The one or more activation conditions can be met if the control unit 100 determines that the dosing system 52 is ready for dosing. In particular, the control unit can determine that the dosing system 52 is ready for dosing if the dosing pump has been pre-filled and if the pressure within the first leg 22A and / or the second leg 22B is above a certain threshold. The one or more activation conditions are described above with reference to Fig. 6. In response to the determination that one or more activation conditions are met, the control unit 100 proceeds to step 704.Alternatively, the control unit 100 can proceed to step 714, where the control unit 100 is configured to set a timeout flag configured to stop the diagnostic procedure 700 if the control unit 100 is unable to determine within a specified time period whether any mechanical or electrical manipulation has taken place on the after-treatment system 22. In step 704, the control unit 100 is configured to determine whether the leg pressure values ​​(e.g., of the first leg 22A and the second leg 22B) are stable. For example, the control unit 100 calculates a standard deviation of the pressure value at each leg for a predetermined time period (e.g., 1 minute, 2 minutes, 3 minutes, etc.). The control unit 100 compares the calculated standard deviation to a threshold value (e.g., 2%, 4%, 2% to 5%, etc.). If the standard deviations of both legs are within the threshold value, the control unit 100 determines that the leg pressure values ​​are stable. The stable pressure values ​​refer to pressure values ​​monitored during the period within the standard deviation threshold. The control unit 100 stores the constant pressure values ​​measured in the first step (referred to here, for example, as step 1 pressure values) in a local device or memory.In certain cases, the control unit 100 stores the pressure values ​​from step 1 in a remote data storage device. The stored pressure values ​​can be at least one data set of pressure values ​​calculated or monitored during the specified time period, a summarized pressure value (e.g., average or mean), a range of pressure values, etc. In step 706, the control unit 100 is configured to apply a target pressure override to either the first branch 22A or the second branch 22B of the post-treatment system 22. The target pressure override can refer to increasing the target pressure of one of the post-treatment system legs 22A, 22B above a predefined threshold (e.g., above 950 kPa) or to decreasing the target pressure of one of the post-treatment system legs 22A, 22B below a predefined threshold (e.g., below 750 kPa). Applying a target pressure override to one of the legs refers to adjusting (e.g., increasing or decreasing depending on the configuration of the target pressure override) the pressure for that leg, so that the control unit 100 can adjust the commands to the metering pumps 53A, 53B, for example, to increase or decrease the pump speed to reach or match the overridden target pressure.At a relatively higher or lower target pressure value, the pump speed is increased or decreased to raise or lower the pressure in one of the legs so that the target pressure determined by the target pressure override is achieved. For example, the control unit 100 can increase the pump speed to achieve a higher target pressure or decrease the pump speed to lower the target pressure. The metering unit 56 can have a recirculation flow that returns to the reducing agent source 54 to maintain a stable pressure in the metering system 52 when not metering. When metering is requested, the metering pump 53 can run at a speed that produces a flow rate equal to the sum of the metered flow rate and the recirculation flow rate. The target pressure value used for target pressure override can be predefined by the administrator of the control unit 100 or updated by the operator I / O device 120 according to an instruction. In some embodiments, exceeding the target pressure value may involve the control unit 100 sending a command to the dosing system 52 to increase or decrease the reducing agent dosage for a specified duration based on a predefined target pressure override value. The duration may be based on the pressure value being changed by a predetermined value or on a timer value. In step 708, the control unit 100 is configured to determine whether the leg pressure values ​​(e.g., of the first leg 22A and the second leg 22B) are stable. The control unit 100 can also be configured to determine average pressure values ​​in both the first leg 22A and the second leg 22B. For example, the control unit 100 calculates a standard deviation of the pressure value in each leg for a predetermined time period (e.g., 1 minute, 2 minutes, 3 minutes, etc.). The control unit 100 compares the calculated standard deviation to a threshold value (e.g., 2%, 4%, 2% to 5%, etc.). If the standard deviations of both legs are within the threshold value, the control unit 100 determines that the leg pressure values ​​are stable. Stable pressure values ​​refer to pressure values ​​monitored during the period within the standard deviation threshold.The control unit 100 stores the constant pressure values ​​measured in the second step (referred to here, for example, as step 2 pressure values) in the local storage device or local memory after applying the target pressure override. In some cases, the control unit 100 stores the pressure values ​​determined in step 2 in a remote data storage device. The stored pressure values ​​can be at least one data set of pressure values ​​calculated or monitored during the time period, a summed pressure value (e.g., average or mean), a range of pressure values, etc. In step 710, the control unit 100 compares the pressure values ​​determined at 704 in step 1 with the pressure values ​​determined at 708 in step 2. Specifically, the control unit 100 can compare the pressure values ​​to determine any difference between the pressure values ​​measured in the post-treatment system legs 22A and 22B before and after the target pressure override was applied in step 706. In one embodiment, the target pressure for both post-treatment system legs 22A and 22B can initially be set to 850 kPa. In such an embodiment, a target pressure override can be applied to the first branch 22A, thereby increasing the target pressure from 850 kPa to 950 kPa. While in the embodiment described here the target pressure is first set to 850 kPa and then increased to 950 kPa to determine whether manipulation has occurred, the procedure 700 can be performed with any values.For example, the initial target pressure can be set to various values ​​(e.g., 600, 750, etc.) and then increased by a predetermined amount (e.g., 100 kPa, 150 kPa, etc.). Alternatively, the initial target pressure can be set to various values ​​(e.g., 750 kPa, 800 kPa, 850 kPa, 950 kPa, etc.) and then decreased by a predetermined amount (e.g., 100 kPa, 200 kPa, etc.). The pressure change observed in the post-treatment system, regardless of whether the target pressure was increased or decreased, can then be analyzed to determine if any manipulation of the post-treatment system has occurred. Target pressure override may only be applied to one leg at a time. Therefore, the target pressure in the second leg (22B) should remain at 850 kPa if no manipulations have been performed on the system.Therefore, in this example, the pressure values ​​from step 1 are 850 kPa for the first leg (22A) and the second leg (22B), while the pressure values ​​from step 2 are 950 kPa and 850 kPa, respectively, for the first leg (22A) and the second leg (22B). In step 710, the control unit 100 compares the pressure values ​​from step 1 with the pressure values ​​from step 2 to determine whether manipulation has occurred in the post-treatment system 22. In a healthy, unmanipulated system, the difference between the pressure values ​​from step 1 and the pressure values ​​from step 2 in the overridden leg is above a certain threshold, while the difference between the pressure values ​​from step 1 and the pressure values ​​from step 2 in the leg where the target pressure override was not applied is below a certain threshold.In a manipulated system, the difference between the pressure values ​​of step 1 and the pressure values ​​of step 2 in the overridden leg is, in some implementations, not above a certain threshold, while the difference between the pressure values ​​of step 1 and the pressure values ​​of step 2 in the leg to which the target pressure override was not applied is not below a certain threshold. In other embodiments, in a manipulated system, the difference between the pressure values ​​of step 1 and the pressure values ​​of step 2 in the overridden leg and the leg to which the target pressure override was not applied is, in each case, above a certain threshold. In some embodiments, in step 712, the control unit 100 either generates an error message (an error indicating a misplacement of the sensor or metering pump) or clears the error message (or terminates the diagnostic procedure without generating the message). For example, if the difference between the pressure values ​​from step 1 and the pressure values ​​from step 2 in the overridden leg is above a certain threshold, and the difference between the pressure values ​​from step 1 and the pressure values ​​from step 2 in the leg to which the target pressure override was not applied is below a certain threshold, the control unit 100 determines that the pressure sensors and / or metering pumps within the aftertreatment system 22 are not displaced.Otherwise, if the difference between the pressure values ​​of step 1 and the pressure values ​​of step 2 in the overridden leg does not exceed a certain threshold, while the difference between the pressure values ​​of step 1 and the pressure values ​​of step 2 in the leg to which the target pressure override was not applied does not fall below a certain threshold, the control unit 100 determines that the pressure sensors and / or metering pumps are not located in the desired positions within the post-treatment system 22. In this case, the control unit 100 is configured to generate a display (e.g., an error message) regarding the incorrect placement of the pressure sensor and / or metering pump. In various embodiments, the diagnostic procedure 700 is performed in response to the starting of the motor 20. For example, in response to a motor start event, the control unit 100 can perform the operations with respect to the first section 22A (e.g., applying a target pressure override to the first section 22A). In response to a second motor start event, the control unit 100 can perform the operations with respect to the second leg 22B (e.g., applying a target pressure override to the second leg 22B). In some cases, the control unit 100 can perform the operations with respect to the first leg 22A in the first attempt and with respect to the second leg 22B in the second attempt, or vice versa. With reference to Figures 8A-8C, an example process flow diagram of a diagnostic method 800 for performing an example dosing manipulation detection according to Figure 7 is now shown according to an example embodiment. The processes, operations, or steps of the method 800 can be performed, operated, or executed by the components (e.g., control unit 100, I / O device 120, post-treatment system 22, sensors, etc.) of the system 10, the data processing system, the cloud computing environment, or other devices described herein in conjunction with Figures 1-7. For example, additional or alternative operations of the method 800 can be performed by one or more circuits of the control unit 100. Additionally or alternatively, some operations of the method 800 can be performed by a remote device, for example, a remote data processing system.In various embodiments, the method 800 can represent a sequence of instructions or steps to be carried out by one or more components of the system 10 or other devices. In step 802, the control unit 100 initiates the diagnostic procedure for detecting electrical and mechanical tampering. The control unit 100 can initiate the diagnostic procedure after determining whether the dosing systems 52A, 52B are ready for dosing. In some embodiments, the control unit 100 can determine that the dosing system 52 is ready for dosing based on the fulfillment of one or more activation conditions. In some embodiments, the control unit 100 can determine that the dosing system 52 is ready for dosing by determining that the dosing pumps in the dosing system 52 have been pre-filled and that the pressure in the post-treatment system legs 22A, 22B has reached a certain threshold (e.g., 850 kPa). The one or more activation conditions can be fulfilled if the control unit 100 determines that no other system continuity faults exist in the system.For example, if there is a pressure sensor fault or a metering pump fault in the aftertreatment system 22, the control unit 100 cannot use these components to diagnose the aftertreatment system 22 and determine any possible manipulation, as the other faults could interfere with such a diagnosis. One or more activation conditions can be met if the control unit 100 determines that no other diagnostic processes are being performed. For example, if one or more system components (e.g., the pressure sensor 16, etc.) are being used to perform another diagnostic procedure, the control unit 100 cannot use these components to diagnose the aftertreatment system 22, as the other diagnostic processes could interfere with such a diagnosis.If it is determined that the activation conditions are met, the control unit 100 can be configured to determine that the dosing system 52 is ready for dosing and proceed to step 804. Otherwise, the procedure 800 remains at step 802 until the control unit 100 determines that the dosing system 52 is ready for dosing. In step 804, the control unit 100 determines whether sufficient time has elapsed since it performed and completed other pressure diagnostics. For example, a urea dosing system functional monitor (UDFM) connected to the control unit 100 may be configured to also perform a diagnostic procedure using the pressure sensors to determine a fault in the dosing system 52. In such a case, the control unit 100 should not perform diagnostic method 800 while the UDFM is also performing a diagnostic method. Therefore, in step 804, the control unit 100 determines whether a certain period of time elapsed since the completion of the diagnostic method by the UDFM exceeds a certain threshold. In other embodiments, the control unit 100 may alternatively determine that sufficient time has elapsed if the UDFM diagnostic procedure has a timeout (i.e.,(could not be completed within a certain time period). If control unit 100 determines that sufficient time has elapsed since the execution and completion of the other pressure diagnoses, control unit 100 proceeds to step 806. Otherwise, procedure 800 remains at step 806 until control unit 100 determines that sufficient time has elapsed. In step 806, the control unit 100 determines a first pressure value for the first dosing system 52A (abbreviated L1 in the figure) and a second pressure value for the second dosing system 52B (abbreviated L2 in the figure) at a first target pressure (e.g., 850 kPa). The control unit 100 determines the first pressure value based on a measured value or a measurement from the first pressure sensor (e.g., pressure sensor 16, which is connected to or intended to measure the pressure of the first dosing system 52A). The control unit 100 determines the second pressure value based on a measured value from the second pressure sensor (e.g., pressure sensor 16, which is associated with or intended to measure the pressure of the second dosing system 52B), as described above with reference to Fig. 6. In step 808, the control unit 100 determines whether the pressure values ​​of the first dosing system 52A or the second dosing system 52B are within a specific range. Specifically, the control unit 100 can determine whether the pressure values ​​are below a second threshold (e.g., 700 kPa, etc.) or above a third threshold (e.g., 1100 kPa, etc.). The second threshold described with reference to Fig. 8 is separate and differs from the second threshold described with reference to Fig. 6. If the pressure values ​​of the first dosing system 52A or the second dosing system 52B are not within a certain range, the control unit 100 resets the determination of the average pressure values ​​in step 810 to 0 and then waits for a short period of time (e.g. 5 seconds, 10 seconds, 15 seconds, etc.) in step 812 before returning to step 806 to ensure that the pressure values ​​are cleared.In some embodiments, the short period can specify the time required for the pressure values ​​of the first metering system 52A and the second metering system 52B to reach the initial or first target pressure (e.g., 850 kPa, etc.). If the pressure values ​​of the first metering system 52A or the second metering system 52B are within a certain range, the control unit 100 proceeds to step 814. In step 814, the control unit 100 determines whether the pressure values ​​of the first dosing system 52A and the second dosing system 52B are below a first threshold (e.g., 750 kPa). The second threshold, described with reference to Fig. 8, is separate and differs from the second threshold described with reference to Fig. 6. If the pressure values ​​of both the first dosing system 52A and the second dosing system 52B are below the first threshold, the control unit 100 proceeds to step 850, which is described in more detail below with reference to Fig. 8C. If the pressure values ​​of both the first dosing system 52A and the second dosing system 52B are not below the first threshold, the control unit 100 proceeds to step 816 in Fig. 8B. In step 816, the control unit 100 determines whether the pressure value of the first metering system 52A is below the first threshold (e.g., 750 kPa, etc.). If the pressure value of the first metering system 52A is below the first threshold, the control unit 100 can, in step 818, designate the second metering system 52B as the leg to which the target pressure override is to be applied (e.g., override leg). Otherwise, if the pressure of the first metering system 52A is not below the first threshold, the control unit 100 can designate the first metering system 52A as the leg to which the target pressure override is applied in step 820 (e.g., override leg). This allows control unit 100 to ensure that the target pressure override is not applied to a leg whose average pressure is below the first threshold, since increasing the pressure in such a leg would not create a sufficient difference (e.g.a difference above a certain threshold) between the overcontrolled leg and the non-overcontrolled leg would result. If a sufficient difference cannot be determined, the diagnostic procedure would not be able to determine whether manipulation of the dosing system 52 has occurred. In step 822, the control unit 100 applies the target pressure override to either the first dispensing system 52A or the second dispensing system 52B, depending on the decision made in steps 816-820. For illustration, the control unit 100 applies the target pressure override to the first dispensing system 52A. In some embodiments, the control unit 100 applies the target pressure override to increase the target pressure for the dispensing system 52 by a specific predetermined amount relative to the steady-state pressure (e.g., 100 kPa, 150 kPa, etc.) for a specific period of time (e.g., 10 seconds, 20 seconds, etc.). In some cases, the specific period for applying the target pressure override can be predefined by the administrator. In some other cases, the period is based on the time required for the first print value to change by a predetermined percentage or amount, for example 5%, 10%, 15%, 20%, etc.In some embodiments, the predetermined percentage can be based on the trial. In this case, the control unit 100 configures or sets a relatively lower percentage (e.g., 5%) for a first trial to detect tampering than for a second trial (e.g., 10%, 15%, etc.). In step 824, the control unit 100 determines a third average pressure value for the first dosing system 52A (abbreviated L1 in the figure) and a fourth average pressure value for the second dosing system 52B (abbreviated L2 in the figure). After applying the target pressure override to the first dosing system 52A, the control unit 100 determines a third pressure value based on a reading or measurement from the first pressure sensor (e.g., pressure sensor 16, which is connected to or intended to measure the pressure of the first dosing system 52A). The control unit 100 determines the fourth pressure value based on a reading from the second pressure sensor (e.g., pressure sensor 16 is assigned to or intended to measure the pressure of the second dosing system 52B). These measured pressure values ​​can be used to determine the steady-state pressure values ​​of the first dosing system 52A and the second dosing system 52B.For example, the control unit 100 recognizes that the readings from the first and second pressure sensors are within a predefined standard deviation (e.g., 2%, 3%, etc.) for at least a predefined period of time. The control unit 100 aggregates the pressure sensor values ​​(e.g., average, mean, median, etc.) for each leg over a specific period to determine an average pressure value. Based on the aggregated pressure sensor values, the control unit 100 determines, for example, the third average pressure value and the fourth average pressure value. In step 826, the control unit 100 determines whether the pressure values ​​of the first dosing system 52A or the second dosing system 52B are within a specified range. Specifically, the control unit 100 can determine whether the pressure values ​​are below a second threshold (e.g., 700 kPa, etc.) or above a third threshold (e.g., 1100 kPa, etc.). If the pressure values ​​of the first dosing system 52A or the second dosing system 52B are not within the specified range, the control unit 100 resets the determination of the average pressure values ​​in step 828 to 0 and then proceeds to step 830. In step 830, the control unit 100 is configured to determine whether a timeout has occurred. A timeout may refer to a status of dosing system 52 indicating that the pressure is unstable and the diagnostic method cannot continue.If the timeout in step 830 occurs, the control unit 100 can be configured to set an unstable pressure error in step 834 and then proceed to step 846, which is described in more detail below. If the timeout in step 830 does not occur, the control unit 100 can be configured to wait a short period (e.g., 5 seconds, 10 seconds, 15 seconds, etc.) in step 832 before returning to step 824. In some embodiments, the short period can specify the time required for the pressure values ​​of the first metering system 52A and the second metering system 52B to reach the second target pressure (e.g., 950 kPa, etc.) specified by the target pressure override. If the pressure values ​​of the first dosing system 52A or the second dosing system 52B are within a certain range, the control unit 100 proceeds to step 836. In step 836, the control unit 100 determines whether the third average pressure value for the first dosing system 52A and the fourth average pressure value for the second dosing system 52B are below the first threshold (e.g., 750 kPa, etc.). If either the third or the fourth average pressure value is below the first threshold, the control unit 100 determines that the pressure sensor and / or the dosing pump are incorrectly positioned and proceeds to step 850. In step 850, the control unit 100 generates an error message (setting an error indicating a misplacement of the sensor or the dosing pump). After generating an error message in step 850, the control unit 100 resets the target pressure for the first dosing system 52A and the second dosing system 52B to the first target pressure in step 852. The diagnostic procedure is then terminated.If the third average pressure value and the fourth average pressure value are not below the first threshold, the control unit proceeds to step 838. In step 838, the control unit 100 is configured to determine a first difference between the third and first pressure values ​​and a second difference between the fourth and second pressure values ​​(e.g., S2 Avg - S1 Avg for each leg L1 and L2). In step 840, the control unit 100 can also be configured to determine a third difference between the first and second differences. In step 841, the control unit 100 can then be configured to compare the third difference with a fourth threshold (e.g., 55 kPa). If the third difference is below the fourth threshold, the control unit 100 determines that the pressure sensor and / or the metering pump are incorrectly positioned and proceeds to step 850, which is described in more detail above. If the third difference is not above the fourth threshold, the control unit 100 proceeds to step 842. In step 842, the control unit 100 is configured to determine whether the first difference is greater than the fourth threshold (e.g., 55 kPa) and the second difference is less than the fifth threshold (e.g., 20 kPa). As described above, the first difference represents the pressure difference in the first dosing system 52A before and after the application of the target pressure override to the first dosing system 52A. In an unmodified dosing system, the first difference should be above the fourth threshold, as the target pressure override should have increased the pressure in the first dosing system 52A by a specific value (e.g., 100 kPa, etc.). Furthermore, the second difference represents the pressure difference in the second dosing system 52B before and after the application of the target pressure override to the first dosing system 52A.In an untampered dosing system, the second difference is below the fifth threshold because the target pressure override should have no effect on the second dosing system 52B, as the control unit 100 only applied the target pressure override to the first dosing system 52A. Therefore, if the first difference is above the fourth threshold and the second difference is below the fifth threshold, the control unit 100 determines that the pressure sensor and / or the dosing pump have not been adjusted. If it is determined that the pressure sensor and / or the dosing pump have not been adjusted, the control unit 100 clears the fault indicator and, in step 844, generates a message indicating that no electrical or mechanical manipulation has been performed on dosing system 52.However, if the first difference is not above the fourth threshold and the second difference is not below the fifth threshold, the control unit 100 determines that no diagnostic evaluation can be performed and proceeds to step 846. In step 846, the control unit 100 resets the target pressure for the first metering system 52A and the second metering system 52B to the first target pressure and proceeds to step 848. In step 848, the control unit 100 waits for the next key cycle to restart the diagnostic procedure 800. A key cycle can refer to the process of turning a vehicle off and then on again. With reference to Figures 9A-9B, a first set of example graphs is now shown, illustrating the behavior of a healthy post-treatment system (Graph 900) and a post-treatment system with dosing manipulation (Graph 910) according to an example embodiment. Specifically, Graphs 900 and 910 show test bench data when a dosing system has been electrically manipulated (e.g., when the pressure sensor has been incorrectly connected or positioned), compared to a healthy system. Graph 900 illustrates the pressure behavior in the first leg 22A and the second leg 22B of a healthy post-treatment system that has not been electrically manipulated. Graph 900 includes a first section 903, which represents the target pressure applied to the first leg 22A (902) and the second leg 22B (904). In the embodiment shown in Graph 900, the target pressure for the first leg 22A is set to a first value (e.g. 950 kPa etc.).) is set, while the target pressure for the second leg 22B is set to a second value (e.g., 900 kPa, etc.). Graph 900 also includes a second section 905, which represents the pressure values ​​measured over a specific period. As can be seen from Graph 900, the pressure measurements for the first leg 22A and the second leg 22B differ significantly (e.g., by more than 20 kPa) and approach their respective target pressures. A pressure measurement "approaches" a target pressure when the actual pressure measurement is within a certain range of the target pressure (e.g., within 5 kPa of the target pressure). Specifically, the measured pressure of the first leg 22A at 906 is approximately 944.3 kPa, while the measured pressure of the second leg 22B at 908 is approximately 902 kPa.Since the pressure values ​​of the first leg 22A and the second leg 22B do not correspond to the same target pressure, it can be determined that no pressure sensor in the post-treatment system 22 was incorrectly placed or incorrectly connected. In contrast, Graph 910 shows the pressure behavior within the first leg 22A and the second leg 22B of a post-treatment system with dosing manipulation. Graph 910 includes a first section 913, which shows the target pressure applied to the first leg 22A (912) and the second leg 22B (914). In the embodiment shown in Graph 910, the target pressure for the first leg 22A is set to a third pressure value (e.g., 950 kPa, etc.), while the target pressure for the second leg 22B is set to a fourth pressure value (e.g., 900 kPa, etc.). Graph 910 also includes a second section 915, which shows the pressure measurements for the first leg 22A and the second leg 22B over a specific period of time. As can be seen from graph 910, the pressure measurements for the first leg 22A and the second leg 22B do not show any significant difference (e.g., over 20 kPa). Furthermore, the pressure measurements do not approach their respective target pressures.Specifically, the measured pressure of the first leg 22A at 916 is approximately 914.8 kPa, while the measured pressure of the second leg 22B at 918 is approximately 904.2 kPa. While the pressure measurements for the second section 22B are close to the target pressure (e.g., 904.2 kPa actual value versus 900 kPa target pressure), the pressure measurements for the first section 22A are not close to the target pressure (e.g., 914.8 kPa actual value versus 950 kPa target pressure). Since the pressure values ​​of the first leg 22A and the second leg 22B do not differ significantly (e.g., within 20 kPa) and follow the same target pressure, it can be determined that a pressure sensor in the post-treatment system 22 has been incorrectly placed or connected. With reference to Figures 10A-10B, a first set of example graphs is now shown, illustrating the behavior of a healthy post-treatment system (Graph 1000) and a post-treatment system with dosing manipulation (Graph 1010) according to an example embodiment. Specifically, Graphs 1000 and 1010 show the behavior when a dosing system has been mechanically manipulated (e.g., when the dosing pump has been incorrectly connected or positioned) compared to a healthy system. Graph 1000 illustrates the pressure behavior in the first leg 22A and the second leg 22B of a healthy post-treatment system that has not been mechanically manipulated. Graph 1000 includes a first section 1003, which shows the target pressure applied to the first leg 22A (1002) and the second leg 22B (1004). In the embodiment shown in Graph 1000, the target pressure for the first leg 22A is set to a fifth pressure value (e.g. 850 kPa etc.).) set, while the target pressure for the second leg 22B is set to a sixth pressure value (e.g., 900 kPa, etc.). Graph 1000 also includes a second section 1005, which shows pressure measurements taken over a specific period. As can be seen from Graph 1000, the pressure measurements for the first leg 22A and the second leg 22B show a significant difference (e.g., over 70 kPa) and approach their respective target pressures. A pressure measurement “approaches” a target pressure when the actual pressure measurement is within a certain range of the target pressure (e.g., within 15 kPa of the target pressure). What is considered a “significant difference” can vary depending on the calibration of one or more components of the post-treatment system and the type of manipulation performed within the post-treatment system.For example, when evaluating electrical manipulation, the significant difference may be in the range of 10 to 30 kPa, whereas when evaluating mechanical manipulation, the significant difference may be in the range of 60 to 90 kPa. At 1006, the measured pressure of the first leg 22A is approximately 833.3 kPa, while the measured pressure of the second leg 22B at 1008 is approximately 913 kPa. Since the pressure values ​​of the first leg 22A and the second leg 22B do not correspond to the same target pressure (i.e., there is a significant difference between the pressure values), it can be determined that the dosing pump in the post-treatment system 22 was not incorrectly positioned or connected. In contrast, Graph 1010 shows the pressure behavior within the first section 22A and the second section 22B of a post-treatment system with dosing manipulation. Graph 1010 includes a first section 1013, which shows the target pressure applied to the first leg 22A (1012) and the second leg 22B (1014). In the embodiment shown in Graph 1010, the target pressure for the first section 22A is set to a seventh pressure value (e.g., 850 kPa, etc.), while the target pressure for the second section 22B is set to an eighth pressure value (e.g., 950 kPa, etc.). Graph 1010 also includes a second section 1015, which shows the pressure measurements for the first leg 22A and the second leg 22B over a specific period. As can be seen from graph 1010, the pressure measurements for the first leg 22A and the second leg 22B show no significant difference (e.g. over 70 kPa).Furthermore, the pressure measurements do not approach their respective target pressures. Specifically, the measured pressure of the first leg 22A at 1016 is approximately 897.2 kPa, while the measured pressure of the second leg 22B at 1018 is approximately 960.2 kPa. While the pressure measurements for the second leg 22B are close to the target pressure (e.g., 960.2 kPa actual value versus 950 kPa target pressure), the pressure measurements for the first leg 22A are not close to the target pressure (e.g., 897.2 kPa actual value versus 850 kPa target pressure). Since the pressure values ​​of the first leg 22A and the second leg 22B do not differ significantly (e.g., within 70 kPa) and follow the same target pressure (e.g., 950 kPa), it can be determined that a dosing pump in the post-treatment system 22 has been incorrectly positioned or connected. With reference to Fig. 11, an example of a process flow diagram of a second diagnostic method 1100 for detecting mechanical or electrical manipulations in the post-treatment system of Fig. 1 and / or Fig. 2 is shown according to an exemplary embodiment. The processes, operations, or steps of the method 1100 can be performed, operated, or executed by the components (e.g., control unit 100, I / O device 120, post-treatment system 22, sensors, etc.) of the system 10, the data processing system, the cloud computing environment, or other devices described herein in connection with Figs. 1-10. For example, additional or alternative operations of the method 1100 can be performed by one or more circuits of the control unit 100. Additionally or alternatively, some operations of the method 1100 can be performed by a remote device, for example, a remote data processing device. In step 1102, the control unit 100 is configured to determine whether one or more of the activation conditions described above with reference to Fig. 6 are met. In step 1104, the control unit 100 is configured to pre-fill a first metering pump connected to the first metering system 52A, while delaying the pre-filling of a second metering pump connected to the second metering system 52B for an initial period. Pre-filling a metering pump refers to the process of preparing the metering pump to supply reducing agent to the metering units 56A and 56B. Pre-filling the metering pumps may include purging air from the pump and the reducing agent delivery lines 58A-58B. In some cases, the initial pre-filling period for the first metering pump may be predefined by the administrator. In other cases, the period is based on the time required for the pre-filling process to complete. In step 1106, the control unit is configured to determine, in response to the pre-filling of the first metering pump in step 1104, a first pressure value connected to the first metering system 52A and a second pressure value connected to the second metering system 52B. The control unit 100 determines the first pressure value based on a reading or measurement from the first pressure sensor (e.g., pressure sensor 16, which is connected to or intended to measure the pressure of the first leg 22A). The control unit 100 determines the second pressure value based on a reading from the second pressure sensor (e.g., pressure sensor 16, which is connected to or intended to measure the pressure of the second leg 22B). In step 1108, the control unit 100 is configured to determine the differences between the first pressure value and the second pressure value. The control unit 100 can measure the difference between the pressure measurements in the first leg 22A and the second leg 22B to determine whether manipulation has occurred. In particular, in the embodiment disclosed in Fig. 11, there is a significant pressure difference (e.g., 70 kPa) between the first pressure value and the second pressure value because, in a healthy, unmanipulated post-treatment system, only the first metering pump is pre-filled. For example, with reference to Fig. 12, example graphs 1202 and 1204 are shown, illustrating a first diagnostic case of the implementation of the diagnostic procedure 1100 according to an example embodiment. In contrast, example graph 1202 shows the pressure values ​​in a manipulated post-treatment system 22 implementing the diagnostic procedure 1100.Since the post-treatment system 22 shown in Graph 1202 is healthy (e.g., no dosage manipulation), the pressure difference 1206 is high (e.g., above a certain threshold such as 20 kPa, 70 kPa, 90 kPa, etc.). In contrast, Example Graph 1202 shows the pressure values ​​in a manipulated post-treatment system 22 that implements the diagnostic procedure 1100. Since the post-treatment system 22 shown in Graph 1204 has dosage manipulation, the pressure difference 1208 is low (e.g., below a certain threshold such as 20 kPa, 70 kPa, 90 kPa, etc.). In step 1110, the control unit 100 is configured to compare the difference between the first and second pressure values ​​with a second threshold value. In some embodiments, the predetermined threshold value can be 70 kPa or 20 kPa, depending on the specific calibration of the post-treatment system 22. In step 1112, the control unit 100 is configured to determine whether the difference is above the predetermined threshold value. If the pressure difference is above the predetermined threshold value, the control unit 100 can determine in step 1114 that no manipulation of the post-treatment system 22 has taken place. Conversely, if the pressure difference is below the predetermined threshold value, the control unit 100 can determine in step 1116 that manipulation has taken place within the post-treatment system 22.The predetermined threshold can indicate a sufficiently large difference between the pressure values ​​to show that the pressure values ​​are not correlated (e.g., if the pressure value in the first leg 22A increases, the pressure value in the second leg 22B also increases). With reference to Fig. 13, an example of a process flow diagram of a third diagnostic method 1300 for detecting mechanical or electrical manipulations in the post-treatment system of Fig. 1 and / or Fig. 2 is shown according to an exemplary embodiment. The processes, operations, or steps of the method 1300 can be performed, operated, or executed by the components (e.g., control unit 100, I / O device 120, post-treatment system 22, sensors, etc.) of the system 10, the data processing system, the cloud computing environment, or other devices described herein in connection with Figs. 1-12. For example, additional or alternative operations of the method 1300 can be performed by one or more circuits of the control unit 100. Additionally or alternatively, some operations of the method 1300 can be performed by a remote device, for example, a remote data processing system.The process is described here in relation to the detection of a malfunction or tampering within the first dosing system 56A. However, this is not to be understood as a limitation. The procedures can also be applied to detect malfunctions or tampering within the second dosing system 56B or other dosing systems within the post-treatment system. In step 1302, the control unit 100 is configured to determine whether one or more of the activation conditions described above with reference to Fig. 6 have been met. In step 1304, the control unit 100 is configured to switch on and operate a first metering pump connected to the first metering system 52A. The control unit 100 is also configured to switch on and operate a second metering pump connected to the second metering system 52B for an initial period. The control unit 100 can switch on and operate the first and second metering pumps by commanding the metering pumps to supply reducing agent to the dispensers 56A and 56B via the reducing agent delivery lines 58A-58B. In some embodiments, the switching on and operation of the first and second metering pumps can occur before or after the metering pumps have been primed. In some cases, the initial operating period for the first metering pump can be predefined by the administrator.In some other cases, the period is based on the time required to raise the pressure in the post-treatment system legs 22A, 22B to a certain level that allows proper operation of the first dosing system 52A and the second dosing system 52B. In step 1306, the control unit 100 is configured to stop the operation of the first metering pump, connected to the first metering system 52A in the first leg 22A, for a second period after the first period has elapsed, while continuing the operation of the second metering pump, connected to the second metering system 52B in the second leg 22B. In a healthy post-treatment system, the pressure connected to the first metering system 52A should fall below a certain threshold when the control unit 100 stops the operation of the first metering pump. In contrast, in an unhealthy and tampered post-treatment system, where the pressure sensor may be incorrectly placed or connected, the pressure connected to the first metering system 52A will not fall below a certain threshold when the control unit 100 stops the operation of the first metering pump.Therefore, the control unit 100 can determine whether there is a manipulation in the after-treatment system 22 by evaluating the pressure difference between the first leg 22A and the second leg 22B. In step 1308, the control unit is configured to determine a first pressure value connected to the first dosing system 52A and a second pressure value connected to the second dosing system 52B in response to the first dosing pump stopping operation while the second dosing pump continues to operate. The control unit 100 determines the first pressure value based on a reading or measurement from the first pressure sensor (e.g., pressure sensor 16, which is connected to or intended to measure the pressure of the first leg 22A). The control unit 100 determines the second pressure value based on a reading from the second pressure sensor (e.g., pressure sensor 16, which is connected to or intended to measure the pressure of the second leg 22B). The first and second pressure values ​​represent the pressure at the outlet of the first DPF element 40A and the second DPF element 40B, respectively. In step 1310, the control unit 100 is configured to determine the differences between the first pressure value and the second pressure value. The control unit 100 can measure the difference between the pressure measurements in the first leg 22A and the second leg 22B to determine whether tampering has occurred. In particular, in the embodiment disclosed in Fig. 13, there should be a significant pressure difference (e.g., 70 kPa) between the first and second pressure values, since in a healthy post-treatment system only the second metering pump is currently in operation. However, in a tampered post-treatment system, there is no significant pressure difference between the first and second pressure values, as the pressure sensor and / or the metering pump may be displaced. For example, with reference to Fig.Figure 14 shows an example graph 1400, which illustrates a second diagnostic case of the execution of the diagnostic procedure 1300 according to an example embodiment. In some embodiments, graph 1400 shows the operating status and pressure values ​​of a first metering pump and a second metering pump within a manipulated post-treatment system. Graph 1400 shows the operating status (e.g., on, off, etc.) of the second metering pump in graph section 1402 and the operating status (e.g., on, off, etc.) of the first metering pump in graph section 1406 over a specific period. Graph 1400 also shows the pressure values ​​of the second metering pump in graph section 1404 and the pressure values ​​of the second metering pump in graph section 1408. In graph section 1402, the second metering pump is still switched on and operating at 1410.Since the second metering pump remains switched on and operating, its pressure corresponds to the target pressure set by control unit 100 (e.g., 875 kPa), as shown in Figure 1412. In contrast, the first metering pump ceased operation at Figure 1414 in graph section 1406. In a healthy post-treatment system, the pressure for the first metering pump would drop because the first metering pump is no longer operating. However, as shown in graph section 1408, the pressure of the second metering pump at Figure 1416 is also close to the target pressure (e.g., 881 kPa), indicating that tampering has occurred in the post-treatment system 22. In step 1312, the control unit 100 is configured to compare the difference between the first and second pressure values ​​with a predetermined threshold. In some embodiments, the predetermined threshold can be 70 kPa or 20 kPa, depending on the specific calibration of the post-treatment system 22. In step 1314, the control unit 100 is configured to determine whether the difference is above the predetermined threshold. If the pressure difference is above the predetermined threshold, the control unit 100 can determine in step 1316 that no manipulation has occurred in the post-treatment system 22. Conversely, if the pressure difference is below the predetermined threshold, the control unit 100 can determine in step 1318 that manipulation has occurred within the post-treatment system 22.The predetermined threshold can indicate a sufficiently large difference between the pressure values ​​to show that the pressure values ​​are not correlated (e.g., if the pressure value in the first leg 22A increases, the pressure value in the second leg 22B also increases). With reference to Fig. 15, an example of a process flow diagram of a fourth diagnostic method 1500 for detecting mechanical or electrical manipulations in the post-treatment system of Fig. 1 and / or Fig. 2 is shown according to an exemplary embodiment. The processes, operations, or steps of the method 1500 can be performed, operated, or executed by the components (e.g., control unit 100, I / O device 120, post-treatment system 22, sensors, etc.) of the system 10, the data processing system, the cloud computing environment, or other devices described herein in connection with Figs. 1-14. For example, additional or alternative operations of the method 1500 can be performed by one or more circuits of the control unit 100. Additionally or alternatively, some operations of the method 1500 can be performed by a remote device, for example, a remote data processing system.The process is described here in relation to the detection of a malfunction or tampering within the first dosing system 56A. However, this is not to be understood as a limitation. The procedures can also be applied to detect malfunctions or tampering within the second dosing system 56B or other dosing systems within the post-treatment system. In step 1502, the control unit 100 is configured to determine whether one or more activation conditions have been met. The one or more activation conditions can be met if the control unit 100 determines that the dosing system 52 is ready for dosing. Specifically, the control unit can determine that the dosing system 52 is ready for dosing if the dosing pump has been primed and if the pressure within the first leg 22A and / or the second leg 22B is above a certain threshold. The one or more activation conditions can also be met if the control unit 100 determines that no other system continuity faults exist.For example, if there is a pressure sensor fault or a metering pump fault in the aftertreatment system 22, the control unit 100 cannot use these components to diagnose the aftertreatment system 22 and determine whether tampering has occurred, because the other faults could interfere with such a diagnosis. One or more activation conditions can be met if the control unit 100 determines that no other diagnostic processes are being performed. For example, if one or more system components (e.g., the pressure sensor 16, etc.) are being used to perform another diagnostic process, the control unit 100 cannot use these components to diagnose the aftertreatment system 22, because the other diagnostic processes could interfere with such a diagnosis. In step 1504, the control unit 100 is configured to determine a first duty cycle, during which a first metering pump connected to the first metering system 52A operates, and a second duty cycle, during which a second metering pump connected to the second metering system 52B operates, prior to a key cycle in an unmodified post-treatment system. The control unit 100 can set the first and second duty cycles as baseline values ​​for a suitable duty cycle, reflecting how a healthy post-treatment system operates. In step 1506, the control unit 100 is configured to determine a third duty cycle, in which a first metering system 52A operates, and a fourth duty cycle, in which the second metering system 52B operates, after the key cycle. In some embodiments, a user must trigger a key-off event (e.g., switch off the vehicle) before performing any mechanical or electrical manipulations on the aftertreatment system 22. After the key-off event, the user can trigger a key-on event (e.g., start the vehicle) to use the vehicle, which may have been tampered with. Therefore, the control unit 100 performs another measurement of the duty cycles for the first and second metering pumps to determine whether the system has been tampered with. In particular, if the third and fourth duty cycles are greater than the first and fourth duty cycles, respectively, by a certain amount, the system may be tampered with.In the second work cycle, the control unit 100 can determine that a manipulation has taken place in the after-treatment system 22. In step 1508, the control unit 100 is configured to determine a first difference between the first and third duty cycles. In step 1510, the control unit 100 is configured to determine a second difference between the second and fourth duty cycles. As mentioned above, these differences between duty cycles allow the control unit 100 to determine whether any manipulation has occurred in the aftertreatment system. In steps 1512-1514, the control unit 100 is configured to compare the first and second differences against a threshold value to determine whether they exceed the threshold. In a healthy aftertreatment system, the duty cycle of the metering pumps should be similar before and after the motor is switched off and on (e.g., within 20 rpm).In contrast, in an unhealthy and tampered-with post-treatment system, where the metering pump may be misaligned, the metering pump supplies two metering units with reducing agent. Therefore, the duty cycle of the metering pump increases because it supplies twice the amount of reducing agent. For example, with reference to Fig. 16, graph 1600 is shown, which depicts a duty cycle for a metering pump in a healthy post-treatment system according to an exemplary embodiment. Graph 1600 shows that the duty cycles 1602, 1604, and 1606 for the first and second metering pumps are between approximately 40 and 60 rpm. In contrast, with reference to Fig. 17, graph 1700 is now shown, which depicts the duty cycle for a metering pump in a tampered metering system after a key actuation event according to an exemplary embodiment.Graph 1700 shows that duty cycles 1702, 1704, and 1706 for the first and second metering pumps are between approximately 80 and 100 rpm. The difference between the duty cycle values ​​shown in Graph 1700 and Graph 1600 exceeds a certain threshold (e.g., above 40 rpm), indicating that there is mechanical or electrical manipulation in the aftertreatment system 22. Therefore, if the first and second differences exceed the threshold (e.g., above 40 rpm), the control unit 100 can be configured to determine in step 1516 that there is mechanical or electrical manipulation in the aftertreatment system 22. If the first and second differences do not exceed the threshold, the control unit 100 can be configured to determine in step 1518 that there is no mechanical or electrical manipulation in the aftertreatment system 22. In some embodiments, a post-treatment system comprises a first metering system, which includes a first metering unit, a first pressure sensor, and a first metering pump. The post-treatment system includes a second metering system, which includes a second metering unit, a second pressure sensor, and a second metering pump. The post-treatment system includes a control unit. The control unit is configured to determine the fulfillment of one or more activation conditions. In response to the fulfillment of one or more activation conditions, the control unit is configured to feed reducing agent to a selective catalytic reduction (SCR) system using the first and second metering systems.The control unit is configured to determine, in response to dosing, a first pressure value connected to the first dosing system using the first pressure sensor, and a second pressure value connected to the second dosing system using the second pressure sensor. The control unit is configured to apply a target pressure override to the first doser for an initial period when the first and second pressure values ​​reach a first threshold. At the end of this initial period, after the target pressure override has been applied, the control unit is configured to determine a third pressure value connected to the first dosing system using the first pressure sensor and a fourth pressure value connected to the second dosing system using the second pressure sensor.The control unit is configured to determine the difference between the third and fourth pressure values. It is configured to compare this difference to a second threshold value. Based on this comparison, the control unit generates an indication of an electrical or mechanical fault in the first dosing system. In some embodiments, the first period is the time required for the first pressure value and the second pressure value to reach a target pressure value specified by the first threshold. In some embodiments, the one or more activation conditions include a condition that there are no faults in the post-treatment system or that the post-treatment system is ready to dispense. In some embodiments, the control unit is configured to determine that an electrical or mechanical fault exists in the first metering system when the difference is below the second threshold. In some embodiments, the first metering system is part of a first post-treatment system leg, which includes a first SCR of the SCR system, and the second metering system is part of a second post-treatment system leg, which includes a second SCR of the SCR system. In some embodiments, a post-treatment system comprises a first metering system, which includes a first metering unit, a first pressure sensor, and a first metering pump. The post-treatment system includes a second metering system, which includes a second metering unit, a second pressure sensor, and a second metering pump. The post-treatment system includes a control unit. The control unit is configured to determine the fulfillment of one or more activation conditions. In response to the fulfillment of one or more activation conditions, the control unit is configured to prime the first metering pump while delaying the priming of the second metering pump for a first period.The control unit is configured to determine, in response to the priming of the first dosing pump, a first pressure value connected to the first dosing system using the first pressure sensor, and a second pressure value connected to the second dosing system using the second pressure sensor. The control unit is configured to determine the difference between the first and second pressure values. The control unit is configured to compare this difference to a threshold value. Based on this comparison, the control unit generates an indication of an electrical or mechanical fault in the first dosing system. In some embodiments, an electrical or mechanical fault is determined to exist in the first metering system if the difference is below the threshold. In some embodiments, the first metering system is part of a first post-treatment leg, which includes a first SCR of an SCR system, and the second metering system is part of a second post-treatment leg, which includes a second SCR of the SCR system. In some embodiments, the first period is the time required for the first pressure value and the second pressure value to reach a target pressure value specified by the first threshold. In some embodiments, the one or more activation conditions include a condition that there are no faults in the post-treatment system or that the post-treatment system is ready to dispense. In some embodiments, a post-treatment system comprises a first metering system, which includes a first metering unit, a first pressure sensor, and a first metering pump. The post-treatment system includes a second metering system, which includes a second metering unit, a second pressure sensor, and a second metering pump. The post-treatment system includes a control unit. The control unit is configured to determine the fulfillment of one or more activation conditions. In response to the fulfillment of one or more activation conditions, the control unit is configured to operate the first metering pump and the second metering pump for a first period. The control unit is configured to stop the operation of the first metering pump after the first period has elapsed, while the second metering pump continues to operate.The control unit is configured to determine, in response to the first dosing pump stopping operation, a first pressure value connected to the first dosing system using the first pressure sensor, and a second pressure value connected to the second dosing system using the second pressure sensor. The control unit is configured to determine the difference between the first and second pressure values. The control unit is configured to compare this difference to a threshold value. Based on this comparison, the control unit generates an indication of an electrical or mechanical fault in the first dosing system. In some embodiments, an electrical or mechanical fault is determined to exist in the first metering system if the difference is below the threshold. In some embodiments, the first metering system is part of a first post-treatment leg, which includes a first SCR of an SCR system, and the second metering system is part of a second post-treatment leg, which includes a second SCR of the SCR system. In some embodiments, the first period is the time required for the first pressure value and the second pressure value to reach a target pressure value specified by the first threshold. In some embodiments, the one or more activation conditions include a condition that there are no faults in the post-treatment system or that the post-treatment system is ready to dispense. In some embodiments, a post-treatment system comprises a first metering system, which includes a first metering unit, a first pressure sensor, and a first metering pump. The post-treatment system includes a second metering system, which includes a second metering unit, a second pressure sensor, and a second metering pump. The post-treatment system includes a control unit. The control unit is configured to determine the fulfillment of one or more activation conditions. In response to the fulfillment of the one or more activation conditions, the control unit is configured to operate the first metering pump and the second metering pump for a first period. After the first period has elapsed, the control unit determines a first duty cycle for the first metering pump and a second duty cycle for the second metering pump before a key cycle.The control unit is configured to determine a third duty cycle for the first metering pump and a fourth duty cycle for the second metering pump after the key cycle. The control unit is configured to determine a first difference between the first and third duty cycles. The control unit is configured to determine a second difference between the second and fourth duty cycles. The control unit is configured to compare the first and second differences against a threshold value. Based on this comparison, the control unit generates an indication of an electrical or mechanical fault in the first metering system. In some embodiments, an electrical or mechanical fault is determined to exist in the first metering system if the difference is below the threshold. In some embodiments, the first metering system is part of a first post-treatment leg, which includes a first SCR of an SCR system, and the second metering system is part of a second post-treatment leg, which includes a second SCR of the SCR system. In some embodiments, the first period is the time required for the first pressure value and the second pressure value to reach a target pressure value specified by the first threshold. In some embodiments, the one or more activation conditions include a condition that there are no faults in the post-treatment system or that the post-treatment system is ready to dispense. III. Construction of exemplary implementations Although this specification contains many specific implementation details, these should not be interpreted as limitations on the scope of the claimed rights, but rather as descriptions of features specific to certain embodiments. Certain features described in this specification in connection with separate embodiments may also be implemented in combination within a single implementation. Conversely, various features described in connection with a single implementation may also be implemented separately in several embodiments or in any suitable subcombination.Furthermore, while features can be described as acting in certain combinations and initially claimed as such, in some cases one or more features can be removed from a claimed combination, and the claimed combination can refer to a subcombination or a variant of a subcombination. As used herein, the terms “essentially”, “generally”, “approximately”, and similar terms are intended to have a broad meaning consistent with their usual and accepted use by those skilled in the art in the field to which the subject matter of this disclosure relates. Those skilled in the art examining this disclosure should understand that these terms serve to describe certain described and claimed features without limiting the scope of these features to the specified precise numerical ranges. Accordingly, these terms are to be interpreted such that inessential or minor modifications or changes to the described and claimed subject matter are to be considered to be within the scope of the invention as specified in the accompanying claims. The terms "coupled" and similar terms, as used here, refer to the direct or indirect connection of two components. Such a connection can be stationary (e.g., permanent) or movable (e.g., removable or detachable). Such a connection can be achieved by integrally forming the two components, or the two components and any additional intermediate components, as a single, unified body, with the two components, or the two components and any additional intermediate components, being attached to one another. The terms "liquid coupled to" and similar terms, as used here, mean that a path is formed between the two components or objects in which a fluid, such as air, exhaust gas, liquid reducing agent, gaseous reducing agent, aqueous reducing agent, gaseous ammonia, etc., can flow, either with or without intervening components or objects. Examples of fluid couplings or configurations for enabling a fluid connection include pipes, channels, or other suitable components that allow the flow of a fluid from one component or object to another. It is important to note that the structure and arrangement of the system shown in the various embodiments serve only for illustration and are not limiting in nature. All changes and modifications that are within the scope and / or scope of the described embodiments shall be protected. It should be noted that some features may not be necessary and that embodiments lacking these features may be considered to be within the scope of the application, the scope being defined by the following claims. When the term "a part" is used, the subject matter may comprise a part and / or the entire subject matter unless expressly stated otherwise. Furthermore, the term "or" is used in its inclusive sense (and not its exclusive sense), so that, for example, when combining a list of elements, it refers to one, some, or all of the elements in the list. Conjunctive phrases such as "at least one of X, Y, and Z" are, unless explicitly stated otherwise, to be understood in context as meaning that an element, term, etc., can be either X, Y, Z, X and Y, X and Z, Y and Z, or X, Y, and Z (i.e., any combination of X, Y, and Z). Therefore, such a conjunctive phrase is generally not intended to imply that certain embodiments require at least one of X, at least one of Y, and at least one of Z, unless otherwise stated. Furthermore, the value ranges used here (e.g., W to P, etc.) include their maximum and minimum values ​​(e.g., W to P includes both W and P, etc.), unless otherwise specified. Moreover, a value range (e.g., W to P, etc.) does not necessarily require the inclusion of intermediate values ​​within the range (e.g., W to P can include only W and P, etc.), unless otherwise specified.

Claims

Post-treatment system comprising: a first dosing system comprising a first doser, a first pressure sensor, and a first dosing pump; a second dosing system comprising a second doser, a second pressure sensor, and a second dosing pump; and a control unit configured to: determine the fulfillment of one or more activation conditions; in response to the fulfillment of one or more activation conditions, dose reducing agent to a selective catalytic reduction (SCR) system using the first dosing system and the second dosing system; in response to dosing, determine a first pressure value associated with the first dosing system using the first pressure sensor and determine a second pressure value associated with the second dosing system using the second pressure sensor;to apply a target pressure override to the first dispenser for an initial period in response to the first and second pressure values ​​reaching an initial threshold; at the end of the initial period after applying the target pressure override, to determine a third pressure value associated with the first dispenser using the first pressure sensor, and a fourth pressure value associated with the second dispenser using the second pressure sensor; to determine a difference between the third and fourth pressure values; to compare the difference with a second threshold; and to generate an indication of an electrical or mechanical fault in the first dispenser based on the comparison. Post-treatment system according to claim 1, wherein the control unit is further configured to determine that an electrical or mechanical fault exists in the first dosing system when the difference is below the second threshold. Post-treatment system according to claim 1, wherein the first dosing system is part of a first post-treatment system leg comprising a first SCR of the SCR system, and the second dosing system is part of a second post-treatment system leg comprising a second SCR of the SCR system. Post-treatment system according to claim 1, wherein the first period is a period required for the first pressure value and the second pressure value to reach a target pressure value specified by the first threshold value. Post-treatment system according to claim 1, wherein the one or more activation conditions include a condition that there are no faults in the post-treatment system or that the post-treatment system is ready for dosing. Post-treatment system comprising: a first dosing system comprising a first doser, a first pressure sensor, and a first dosing pump; a second dosing system comprising a second doser, a second pressure sensor, and a second dosing pump; and a control unit configured to: determine the fulfillment of one or more activation conditions; in response to the fulfillment of one or more activation conditions, pre-fill the first dosing pump while delaying the pre-filling of the second dosing pump for a first period; in response to the pre-filling of the first dosing pump and the delay in pre-filling the second pump for the first period, determine a first pressure value associated with the first dosing system using the first pressure sensor, and determine a second pressure value associated with the second dosing system using the second pressure sensor;to determine a difference between the first pressure value and the second pressure value; to compare the difference with a threshold value; and to generate an indication of an electrical or mechanical fault in the first dosing system, based on the comparison. Post-treatment system according to claim 6, wherein the control unit is further configured to determine that an electrical or mechanical fault is present in the first dosing system when the difference is below the threshold value. Post-treatment system according to claim 6, wherein the first dosing system is part of a first post-treatment leg comprising a first SCR of an SCR system, and the second dosing system is part of a second post-treatment leg comprising a second SCR of the SCR system. Post-treatment system according to claim 6, wherein the first period is a period required for the first pressure value and the second pressure value to reach a target pressure value. Post-treatment system according to claim 6, wherein one or more activation conditions include a condition that there are no faults in the post-treatment system or that the post-treatment system is ready to dose. Post-treatment system comprising: a first dosing system comprising a first doser, a first pressure sensor, and a first dosing pump; a second dosing system comprising a second doser, a second pressure sensor, and a second dosing pump; and a control unit configured to: determine the fulfillment of one or more activation conditions; in response to the fulfillment of one or more activation conditions, operate the first dosing pump and the second dosing pump for a first period; after the first period has elapsed, stop the operation of the first dosing pump while the operation of the second dosing pump continues;In response to the first metering pump stopping operation, determine a first pressure value associated with the first metering system using the first pressure sensor and determine a second pressure value associated with the second metering system using the second pressure sensor; determine a difference between the first and second pressure values; compare the difference with a threshold value; and generate an indication of an electrical or mechanical fault in the first metering system based on the comparison. Post-treatment system according to claim 11, wherein the control unit is further configured to determine that an electrical or mechanical fault is present in the first dosing system when the difference is below the threshold value. Post-treatment system according to claim 11, wherein the first dosing system is part of a first post-treatment leg comprising a first SCR of an SCR system, and the second dosing system is part of a second post-treatment leg comprising a second SCR of the SCR system. Post-treatment system according to claim 11, wherein the first period is a period required for the first pressure value and the second pressure value to reach a target pressure value. Post-treatment system according to claim 11, wherein one or more activation conditions include a condition that there are no faults in the post-treatment system or that the post-treatment system is ready to dose. Post-treatment system comprising: a first dosing system comprising a first doser, a first dosing pump, and a first pressure sensor; a second dosing system comprising a second doser, a second dosing pump, and a second pressure sensor; and a control unit configured to: determine the fulfillment of one or more activation conditions; determine, in response to the fulfillment of one or more activation conditions, a first duty cycle for the first dosing pump and a second duty cycle for the second dosing pump prior to a key cycle; determine a third duty cycle for the first dosing pump and a fourth duty cycle for the second dosing pump after the key cycle; determine a first difference between the first duty cycle and the third duty cycle; determine a second difference between the second duty cycle and the fourth duty cycle;to compare the first difference and the second difference with a threshold value; and to generate an indication of an electrical or mechanical fault in the first dosing system, based on the comparison. Post-treatment system according to claim 16, wherein the control unit is further configured to determine that an electrical or mechanical fault is present in the first dosing system when the difference is below the threshold value. Post-treatment system according to claim 16, wherein the first dosing system is part of a first post-treatment leg comprising a first SCR of an SCR system, and the second dosing system is part of a second post-treatment leg comprising a second SCR of the SCR system. Post-treatment system according to claim 16, wherein the first period is a period required for the first pressure value and the second pressure value to reach a target pressure value. Post-treatment system according to claim 16, wherein one or more activation conditions include a condition that there are no faults in the post-treatment system or that the post-treatment system is ready to dose.

Images