CN112727617A

CN112727617A - System and method for predictive control of an exhaust aftertreatment system

Info

Publication number: CN112727617A
Application number: CN201910975131.4A
Authority: CN
Inventors: 刘斌; 周阳; 黄琳
Original assignee: Cummins Inc
Current assignee: Cummins Inc
Priority date: 2019-10-14
Filing date: 2019-10-14
Publication date: 2021-04-30
Anticipated expiration: 2039-10-14
Also published as: CN112727617B

Abstract

Systems, devices, and methods include an exhaust aftertreatment system and a controller. The exhaust aftertreatment system includes an SCR catalyst. The controller is configured to receive information indicative of an upcoming route condition; receiving information indicative of a current vehicle operating condition; determining a predicted exhaust temperature of the vehicle at the upcoming location based on the information indicative of the upcoming route condition and the current vehicle operating condition; receiving information indicative of a current exhaust temperature; determining a difference between the current exhaust temperature and the predicted exhaust temperature; in response to determining that a difference between the current exhaust temperature and the predicted exhaust temperature is above a predetermined threshold, determining a smoothing command; controlling a vehicle system based on the smoothing command to compensate for a difference between the current exhaust temperature and the predicted exhaust temperature.

Description

System and method for predictive control of an exhaust aftertreatment system

Technical Field

The present disclosure relates to systems and methods for controlling exhaust aftertreatment systems. More specifically, the present disclosure relates to systems and methods for predicting future engine operating conditions and controlling an exhaust aftertreatment system based on the predicted future engine operating conditions.

Background

Internal combustion engine emissions regulations have become increasingly stringent in recent years. Environmental concerns in most parts of the world have driven the implementation of more stringent emissions requirements for internal combustion engines. Accordingly, exhaust aftertreatment systems are increasingly being used to treat engine exhaust to reduce emissions. Exhaust aftertreatment systems are typically designed to reduce the emissions of particulate matter, nitrogen oxides (NOx), hydrocarbons, and other environmentally harmful pollutants. Exhaust aftertreatment systems treat engine exhaust using catalysts and reductants to convert NOx in the exhaust to less harmful compounds.

Disclosure of Invention

One embodiment relates to a system. The system includes an exhaust aftertreatment system and a controller. The exhaust aftertreatment system includes a Selective Catalytic Reduction (SCR) catalyst. The controller is configured to receive information indicative of an upcoming route condition. The controller is configured to receive information indicative of a current vehicle operating condition. The controller is configured to determine a predicted exhaust temperature of the vehicle at the upcoming location based on the information indicative of the upcoming route condition and the current vehicle operating conditions. The controller is configured to receive information indicative of a current exhaust temperature. The controller is configured to determine a difference between the current exhaust temperature and the predicted exhaust temperature. The controller is configured to determine the smoothing command in response to determining that a difference between the current exhaust temperature and the predicted exhaust temperature is above a predetermined threshold. The controller is configured to control the vehicle system in accordance with the smoothing command to compensate for a difference between the current exhaust temperature and the predicted exhaust temperature.

Another embodiment relates to an apparatus. The apparatus includes a road information circuit, an exhaust temperature prediction circuit, and an exhaust temperature smoothing circuit. The road information circuit is configured to receive information indicative of an upcoming route condition. The exhaust temperature prediction circuit is configured to receive information indicative of a current vehicle operating condition. The exhaust temperature prediction circuit is configured to determine a predicted exhaust temperature based on information indicative of upcoming route conditions and current vehicle operating conditions. The exhaust temperature prediction circuit is configured to receive information indicative of a current exhaust temperature. The exhaust temperature prediction circuit is configured to determine a difference between the current exhaust temperature and the predicted exhaust temperature. The exhaust temperature smoothing circuit is configured to determine a smoothing command in response to determining that a difference between the current exhaust temperature and the predicted exhaust temperature is above a predetermined threshold. The exhaust temperature smoothing circuit is configured to control a vehicle system in accordance with a smoothing command to compensate for a difference between a current exhaust temperature and a predicted exhaust temperature.

Another embodiment relates to a method. The method includes receiving, by a controller of a vehicle, information indicative of an upcoming route condition. The method includes receiving, by a controller, information indicative of a current vehicle operating condition. The method includes determining, by the controller, a predicted exhaust temperature based on information indicative of upcoming route conditions and current vehicle operating conditions. The method includes receiving, by a controller, information indicative of a current exhaust temperature. The method includes determining, by a controller, a difference between a current exhaust temperature and a predicted exhaust temperature. The difference indicates a predicted change in an amount of reductant associated with a Selective Catalytic Reduction (SCR) catalyst including an exhaust aftertreatment system in exhaust receiving communication with the engine. The method includes determining, by a controller, a smoothing command. The method includes controlling, by the controller, a vehicle system in accordance with the smoothing command to compensate for a difference between the current exhaust temperature and the predicted exhaust temperature to compensate for a predicted change in an amount of reductant bound to the SCR catalyst due to the difference.

These and other features, together with the organization and manner of operation thereof, will become apparent from the following detailed description when taken in conjunction with the accompanying drawings.

Drawings

FIG. 1 is a schematic illustration of an exhaust aftertreatment system having a controller according to an exemplary embodiment.

FIG. 2 is a schematic diagram of the controller of FIG. 1 interacting with various components of the system of FIG. 1, according to an example embodiment.

FIG. 3 is a schematic diagram of a controller of the system of FIG. 1, according to an example embodiment.

FIG. 4 is a flowchart of a method for controlling an engine coupled to the exhaust aftertreatment system of FIG. 1 to reduce the likelihood of temperature spikes in exhaust gas produced by the engine, according to an exemplary embodiment.

FIG. 5 is a time-height plot illustrating travel of the vehicle of FIG. 1 along a portion of a route, according to an example embodiment.

FIG. 6 is a graph illustrating time-temperature of exhaust temperature for the vehicle of FIG. 5 and a conventional vehicle traveling along the route of FIG. 5, according to an example embodiment.

Detailed Description

Following are more detailed descriptions of various concepts related to methods, apparatus, and systems, and embodiments thereof, for predicting a temperature of a Selective Catalytic Reduction (SCR) catalyst in an exhaust aftertreatment system and controlling an engine or exhaust aftertreatment system to bring nitrous oxide (NOx) emissions of an exhaust pipe to or below a predefined NOx threshold and/or reduce reductant slip. The various concepts introduced above and discussed in greater detail below may be implemented in any number of ways, as the described concepts are not limited to any particular implementation. Examples of specific implementations and applications are provided primarily for purposes of illustration.

The engine generates exhaust gases as it propels the vehicle along the route. The engine is coupled to an exhaust aftertreatment system designed to reduce harmful emissions of the exhaust gases. The aftertreatment system may include, among other things, a Selective Catalytic Reduction (SCR) catalyst and a reductant dosing system configured to inject a reductant into the exhaust gas. The SCR catalyst and reductant react with NOx to reduce NOx to less harmful substances. The SCR catalyst is configured to absorb NOx from the exhaust gas. The absorption of the SCR catalyst by the reductant depends on the temperature. In this regard, the SCR catalyst releases the reductant as the exhaust temperature (and therefore the temperature of the SCR catalyst) increases, and absorbs the reductant as the exhaust temperature (and therefore the temperature of the SCR catalyst) decreases.

Due to variations in road conditions (e.g., road conditions and environmental conditions), both the temperature and the composition of the exhaust gas (e.g., NOx content) may change as the vehicle travels along the road. Under certain route conditions (e.g., uphill and downhill driving, wet, etc.), the temperature of the exhaust gas may change rapidly or peak in temperature, which may cause the SCR catalyst temperature to change. Under conditions where the temperature of the SCR catalyst increases due to temperature spikes, the SCR catalyst may release reductant into the exhaust stream, which may result in excess reductant (relative to the amount of NOx) in the exhaust. This may result in unreacted reductant being expelled or slipping through the exhaust aftertreatment system and/or the exhaust pipe of the vehicle. Then, such slipped reducing agent may be discharged to the outside. This condition is referred to as "reductant slip". Under conditions where the temperature of the SCR catalyst decreases due to temperature spikes, the SCR catalyst may absorb reductant relative to the exhaust flow, which may result in an insufficient amount of reductant (relative to the amount of NOx) in the exhaust gas. This may result in unreacted NOx exiting the exhaust aftertreatment system and/or the exhaust pipe of the vehicle. Since the rate of reductant absorption and release to the SCR catalyst is slow with respect to temperature changes, it is difficult to reduce the effect of temperature spikes on reductant absorption and release to the SCR catalyst once absorption or release has begun. Accordingly, it would be advantageous to receive information indicative of upcoming route conditions, predict upcoming temperature peaks, and generate smoothing commands for one or more vehicle operating systems to compensate for the predicted temperature peaks.

Referring generally to the drawings, various embodiments disclosed herein relate to systems, devices, and methods for predicting a temperature of a Selective Catalytic Reduction (SCR) catalyst in an exhaust aftertreatment system and controlling one or more vehicle systems to control or reduce nitrogen oxide (NOx) emissions and/or reductant slip in an exhaust pipe. The vehicle may include a controller configured to: receiving information indicative of an upcoming route condition; receiving information indicative of a current vehicle operating condition; and determining a predicted exhaust temperature based on the information indicative of the upcoming route condition and the current vehicle operating condition. The controller may be configured to receive information indicative of a current exhaust temperature and determine a difference between the current exhaust temperature and a predicted exhaust temperature. The binding of the reducing agent to the SCR catalyst is temperature dependent, which means that the amount of reducing agent bound to the SCR catalyst varies with temperature. More specifically, the SCR catalyst releases the absorbed reductant at higher exhaust temperatures. Thus, the difference between the current exhaust temperature and the predicted exhaust temperature indicates a predicted change in the amount of reductant incorporated into the SCR catalyst. The controller may compare a difference between the current exhaust temperature and the predicted exhaust temperature to a predetermined threshold. In response to determining that the difference is above the predetermined threshold, the controller may then determine a smoothing command configured to responsively change an operating parameter of one or more of the engine, a driveline coupled to the engine, and/or an exhaust aftertreatment system. The controller may then control one or more of the engine, the transmission, and the exhaust aftertreatment system to compensate for the predicted temperature change based on the smoothing command to compensate for a change in the amount of reductant associated with the SCR catalyst due to the predicted temperature change.

Referring now to FIG. 1, a vehicle 10 having an engine system 12 including a controller 14 is shown according to an exemplary embodiment. As shown in FIG. 1, the engine system 12 includes an internal combustion engine, indicated as engine 18, a transmission system 20, and an aftertreatment system, indicated as exhaust aftertreatment system 22.

The transmission system 20 includes a variator 24 and a final drive (not shown). The transmission 24 is coupled to the engine 18 and the final drive. The transmission 24 may be configured as any type of transmission, such as a continuously variable transmission, a manual transmission, an automatic-manual transmission, a dual clutch transmission, or the like. Thus, as the transmission changes from a geared configuration to a continuous configuration (continuously variable transmission), the transmission 24 may include various settings (e.g., gears for gearing) that affect different output speeds based on the input speed received thereby (e.g., from the engine 18, etc.). Like the engine 18 and transmission 24, the final drive may be configured in any configuration depending on the application (e.g., the final drive may be configured as a wheel in automotive applications, a propeller in marine applications, etc.).

According to one embodiment, the engine 18 is configured as a compression ignition internal combustion engine utilizing diesel fuel. However, in various alternative embodiments, engine 18 may be configured as any other type of engine (e.g., spark-ignited) that utilizes any type of fuel (e.g., gasoline, natural gas). Within the internal combustion engine 18, air from the atmosphere is combined with fuel and combusted to power the engine 18. Combustion of the fuel and air in the compression chambers of the engine 18 produces exhaust gases, which are operatively discharged to an exhaust manifold and an exhaust aftertreatment system 22.

An exhaust aftertreatment system 22 is in exhaust receiving communication with the engine 18. In the illustrated example, the exhaust aftertreatment system 22 includes a Diesel Oxidation Catalyst (DOC)26, a Diesel Particulate Filter (DPF)30, a Selective Catalytic Reduction (SCR) system 32 having an SCR catalyst 34, and an ammonia oxidation (AMOx) catalyst 36. The SCR system 32 also includes a reductant delivery system having a reductant source (shown as a Diesel Exhaust Fluid (DEF) source 38) that supplies a reductant (e.g., DEF, ammonia) to a reductant doser 40 via a reductant line (shown as a reductant line 42). It should be noted that the components of the exhaust aftertreatment system 22 may be in any order, or different components and/or different aftertreatment architectures may be used. In another example, the SCR system 32 may include a plurality of reductant dosers 40 positioned along the exhaust aftertreatment system 22. While the illustrated exhaust aftertreatment system 22 includes one of the D0C26, the DPF30, the SCR catalyst 34, and the AMOx catalyst 36 positioned in particular locations relative to each other along the exhaust flow path, in other embodiments, the exhaust aftertreatment system 22 may include more than any of a variety of catalysts positioned in any location relative to each other along the exhaust flow path, as desired. Accordingly, the architecture of the exhaust aftertreatment system 22 shown in FIG. 1 is for illustrative purposes, and not by way of limitation.

In the exhaust flow direction, as indicated by directional arrow 44, exhaust gas enters an inlet conduit 46 of the exhaust aftertreatment system 22 from the engine 18. Exhaust flows from the inlet pipe 46 into the DOC26 and exits the DOC26 into the first portion 48A of the exhaust conduit. Exhaust gas flows from the first portion 48A of the exhaust conduit into the DPF30 and exits the DPF30 into the second portion 48B of the exhaust conduit. Exhaust gas flows from the second portion 48B of the exhaust conduit into the SCR catalyst 34 and exits the SCR catalyst 34 into the third portion 48C of the exhaust conduit. The reductant doser 40 may periodically dose the reductant (e.g., DEF, urea) as the exhaust gas flows through the second portion 48B of the exhaust conduit. Thus, the second portion 48B of the exhaust conduit may act as a decomposition chamber or pipe to facilitate decomposition of the reductant into ammonia. Exhaust gas flows into the AMOx catalyst 36 from the third portion 48C of the exhaust conduit, flows into the AMOx catalyst 36 and exits the AMOx catalyst 36 into the outlet conduit 50 before the exhaust gas is exhausted from the exhaust aftertreatment system 22. Based on the foregoing, in the illustrated embodiment, the DOC26 is located upstream of the DPF30, the DPF30 is located upstream of the SCR catalyst 34, and the SCR catalyst 34 is located upstream of the AMOx catalyst 36. However, in another embodiment, other arrangements of the components of the exhaust aftertreatment system 22 are possible.

The DOC26 may have any of a variety of flow-through designs. Generally, the DOC26 is configured to oxidize at least some particulate matter in the exhaust, such as a soluble organic portion of soot in the exhaust, and to reduce non-combustible hydrocarbons and carbon monoxide (CO) in the exhaust to compounds that are less harmful to the environment. For example, the DOC26 may be configured to reduce the hydrocarbon and CO concentrations in the exhaust to meet the necessary emission standards for these components of the exhaust. An indirect consequence of the oxidizing ability of the DOC26 is that the DOC26 oxidizes NO to NO₂The ability of the cell to perform. In this manner, NO of DOC26₂Is equal to NO in the exhaust gas produced by the engine 18₂Plus NO converted from NO by DOC26₂。

In addition to treating the hydrocarbon and CO concentrations in the exhaust, the DOC26 may also be used for controlled regeneration of the DPF30, the SCR catalyst 34, and the AMOx catalyst 36. This may be accomplished by injecting, or dosing, unburned HC into the exhaust gas upstream of the DOC 26. During contact with the DOC26, the unburned HCs undergo an exothermic oxidation reaction that results in an increase in the temperature of the exhaust exiting the DOC26 and subsequently entering the DPF30, SCR catalyst 34, and/or AMOx catalyst 36. The amount of unburned HC added to the exhaust gas is selected to achieve a desired temperature increase or controlled target regeneration temperature.

The DPF30 may be any of a variety of flow-through or wall-flow designs and is configured to reduce the concentration of particulate matter (e.g., soot and ash) in the exhaust gas to meet or substantially meet required emission standards. The DPF30 traps particulate matter and other constituents, and therefore may require periodic regeneration to combust the trapped constituents.

As discussed above, the SCR system 32 may include a reductant delivery system, pump, and delivery mechanism or dispenser 40 having a reductant (e.g., DEF) source 38. The reductant source 38 may be a container or tank capable of retaining a reductant, such as ammonia (NH3) or DEF (e.g., urea). The reductant source 38 is in communication with a pump reductant supply, which is configured to pump reductant from the reductant source 38 to a doser 40 via a reductant delivery line 42. The doser 40 may be located upstream of the SCR catalyst 34. The doser 40 may be selectively controlled to inject reductant directly into the exhaust gas prior to the exhaust gas entering the SCR catalyst 34. In some embodiments, the reducing agent may be ammonia or DEF, which decomposes to produce ammonia. As briefly described above, ammonia reacts with NOx in the presence of the SCR catalyst 34 to reduce the NOx to less harmful emissions, such as N₂And H₂And O. NOx in the exhaust gas includes NO₂And NO. Typically, in a reducing agent (such as NH)₃) NO when present, by various chemical reactions driven by the catalytic components of the SCR catalyst 34₂And NO are both reduced to N₂And H₂O。

The SCR catalyst 34 may be any of a variety of catalysts known in the art. For example, in some embodiments, the SCR catalyst 34 is a vanadium-based catalyst, and in other embodiments, the SCR catalyst 34 is a zeolite-based catalyst, such as a Cu zeolite catalyst or a Fe zeolite catalyst. The SCR catalyst 34 is configured to bind the reductant in the exhaust gas and promote a reaction between the bound reductant and NOx in the exhaust gas to reduce the NOx in the exhaust gas to less harmful compounds. The SCR catalyst 34 absorbs a reducing agent (e.g., ammonia) in the exhaust gas. The efficiency of the reductant binding to the SCR catalyst 34 is temperature dependent, meaning that the efficiency of the reductant binding to the SCR catalyst 34 varies with temperature. More specifically, the SCR catalyst 34 releases the adsorbed reductant at higher exhaust temperatures. The NOx conversion efficiency of the SCR catalyst 34 is temperature dependent, meaning that the higher the temperature, the more effective the SCR catalyst is in reducing NOx to less harmful emissions. Therefore, both the amount of reducing agent in the exhaust gas and the conversion amount of NOx may vary based on the temperature of the exhaust gas.

AMOx catalyst 36 may be any of a variety of flow-through catalysts configured to react with ammonia to produce primarily nitrogen. As briefly described above, the AMOx catalyst 36 is configured to remove ammonia that has slipped over or exited the SCR catalyst 34 without reacting with NOx in the exhaust. In some cases, the exhaust aftertreatment system 22 may operate with or without the AMOx catalyst 36. Further, although the AMOx catalyst 36 is viewed as a different unit than the SCR catalyst 34 of fig. 1, in some embodiments, the AMOx catalyst 36 can be integrated with the SCR catalyst 34, e.g., the AMOx catalyst 36 and the SCR catalyst 34 can be located within the same housing. According to the present disclosure, the SCR catalyst 34 and AMOx catalyst 36 are positioned in series, with the SCR catalyst 34 positioned before the AMOx catalyst 36. As described above, in various other embodiments, the AMOx catalyst 36 is not included in the exhaust aftertreatment system 22.

Still referring to FIG. 1, exhaust aftertreatment system 22 may include various sensors such as NOx sensors, temperature sensors, engine speed sensors, environmental sensors, weight sensors, and the like. Various sensors may be strategically located throughout the exhaust aftertreatment system 22 and may be in communication with the controller 14 to monitor operating conditions of the exhaust aftertreatment system 22 and/or the engine 18. As shown in FIG. 1, exhaust aftertreatment system 22 includes a first NOx sensor 52 located at or upstream of SCR catalyst 34, a first temperature sensor 54 located at or upstream of SCR catalyst 34, a second NOx sensor 58 located at or downstream of SCR catalyst 34, and a second temperature sensor 60 located at or downstream of exhaust aftertreatment system 22. In some embodiments, the second NOx sensor 58 and/or the second temperature sensor 60 may be positioned at or downstream of the outlet of the exhaust aftertreatment system 22.

First NOx sensor 52 is configured to determine information indicative of a concentration or amount of NOx of the exhaust gas entering exhaust aftertreatment system 22. First temperature sensor 54 is configured to determine information indicative of a temperature of exhaust gas entering exhaust aftertreatment system 22. Second NOx sensor 58 is configured to determine information indicative of an outlet NOx concentration or amount. Second temperature sensor 60 is configured to determine information indicative of a temperature of the exhaust exiting exhaust aftertreatment system 22. Although fig. 1 depicts several sensors (e.g., first NOx sensor 52, first temperature sensor 54, second NOx sensor 58, second temperature sensor 60), it should be understood that in other embodiments one or more of these sensors may be replaced by virtual sensors. In this regard, the amount of NOx at each location may be estimated, determined, or otherwise correlated with various operating conditions of the engine 18 and the exhaust aftertreatment system 22.

An engine speed sensor 62 is coupled to the engine 18 and is configured to determine information indicative of a speed of the engine 18. In some embodiments, environmental sensors may be strategically located outside or near the vehicle 10 and may communicate with the controller 14 to monitor ambient environmental conditions around the vehicle 10. In some arrangements, the environmental sensors may include one or more of a humidity sensor 64, an external temperature sensor 68, and the like. In other embodiments, the controller 14 may be configured to receive information indicative of ambient environmental conditions surrounding the vehicle 10 from a weather server, dispatch server, or the like, via a wireless network. One or more weight sensors 72 may be strategically located within the vehicle 10 to monitor the weight or mass of the vehicle 10. For example, in some embodiments, one or more weight sensors may be positioned on the axles of the vehicle 10. In other embodiments, the controller 14 may be configured to receive information indicative of the weight of the vehicle 10 from weight sensors embedded in the road or loading dock via a wireless network.

FIG. 1 is also shown to include an operator input/output (I/O) device 76. The operator I/O device 76 is communicatively coupled to the controller 14 such that information may be exchanged between the controller 14 and the operator I/O device 76, wherein the information may relate to one or more components of fig. 1 or measurements of the controller 14 (described below). The operator I/O device 76 enables an operator to communicate with the controller 14 and one or more components of the vehicle 10 of fig. 1. For example, the operator I/O devices 76 may include, but are not limited to, an interactive display, a touch screen device, one or more buttons and switches, a voice command receiver, and the like. In various alternative embodiments, the controller 14 and the components described herein may be implemented with non-vehicular applications (e.g., generators). Thus, the operator I/O devices 76 may be specific to those applications. For example, in those cases, the operator I/O devices 76 may include a laptop computer, a tablet computer, a desktop computer, a telephone, a watch, a personal digital assistant, and so forth. Through the operator I/O device 76, the controller 14 may provide diagnostic information, fault or service notifications based on one or more determinations (e.g., determined concentrations of NOx and/or reductants at or near the outlet of the exhaust aftertreatment system 22). For example, in some embodiments, controller 14 may display a notification via operator I/O device 76 that the outlet NOx concentration has exceeded the predetermined outlet NOx threshold for a predetermined period of time. In certain embodiments, the outlet NOx threshold may range between 400-600 mg/kWh, as defined by Chinese national Standard VI. In another example, in some embodiments, controller 14 may display a notification via operator I/O device 76 that the outlet reductant concentration (e.g., the amount of reductant in the exhaust gas exiting exhaust aftertreatment system 22 and/or the amount of reductant in the exhaust gas exiting vehicle 10) has been above a predetermined outlet reductant threshold for a predetermined time. In some embodiments, the outlet reductant threshold may be substantially 10ppm, as defined in National Standard (NS) VI of china.

Also shown in FIG. 1 is an optional route look-ahead system 78 configured to receive information indicative of upcoming route conditions ahead of the vehicle 10. The route look-ahead system 78 is configured to receive information indicative of upcoming route conditions from the

sensors

64, 68 located on the vehicle 10 or from the communication interface 336 (e.g., the communication interface 336 may receive signals indicative of upcoming route conditions via wireless communication with a global positioning system (GPS 204), weather server, etc.). The information indicative of upcoming route conditions may be sensed in substantially real-time or may be information indicative of future or expected route conditions. The upcoming route condition information may include information regarding altitude, road grade, road slope, road curvature, environmental conditions (e.g., humidity), and the like.

Controller 14 is configured to control operation of engine system 12 and is associated with subsystems such as an internal combustion engine 18 and an exhaust aftertreatment system 22. According to one embodiment, the assembly of FIG. 1 is embodied in a vehicle. The vehicle 10 may comprise an on-highway vehicle or an off-highway vehicle including, but not limited to, a delivery truck, a medium range truck (e.g., a pick-up truck), a car, a boat, a tank, an airplane, and any other type of vehicle that employs an exhaust aftertreatment system. As noted above, in various alternative embodiments, the controller 14 may be used with any type of engine exhaust aftertreatment system in a stationary implementation (e.g., a stationary power generation system).

The components of the vehicle 10 may communicate with each other or with external components using any type and any number of wired or wireless connections. For example, the wired connection may include a serial cable, a fiber optic cable, a CAT5 cable, or any other form of wired connection. The wireless connection may include the Internet, Wi-Fi, cellular, radio, Bluetooth, ZigBee, and the like. In one embodiment, a Controller Area Network (CAN) bus provides for the interaction of signals, information, and/or data. The CAN bus includes any number of wired and wireless connections. Because the controller 14 is communicatively coupled to the systems and components of the vehicle 10 of fig. 1, the controller 14 is configured to receive data regarding one or more of the components shown in fig. 1 and 2. For example, the data may include operational data obtained by one or more sensors regarding the operational status of the engine 18, reductant doser 40, SCR catalyst 34, and/or other components (e.g., battery system, motor, generator, regenerative braking system).

The components of FIG. 1 are considered to be embodied in an engine system, and controller 14 may be configured as one or more Electronic Control Units (ECUs). The controller 14 may be separate from or included in at least one of a transmission control unit, an exhaust aftertreatment control unit, a driveline control circuit, an engine control circuit, etc. The function and structure of the controller 14 will be described in more detail in fig. 3.

Referring now to FIG. 2, the controller 14 is a schematic diagram of the communication with the Global Positioning System (GPS)204, the weather server 208, the exhaust aftertreatment system 22, the engine 18, and the drivetrain 20 of the vehicle 10. As discussed in more detail below, the GPS204 may transmit information indicative of the location of the vehicle 10 to the controller 14. In some embodiments, the GPS may send information indicative of upcoming road conditions (e.g., road grade and/or road height) to the controller 14. The weather server 208 may send information indicative of the upcoming environmental conditions (e.g., humidity) to the controller 14. Exhaust aftertreatment system 22 may send information indicative of the operating conditions of exhaust aftertreatment system 22 (e.g., exhaust temperature and NOx level of the exhaust) to controller 14. Controller 14 is configured to predict an upcoming exhaust temperature based on information received from GPS204, meteorological server 208, and/or exhaust aftertreatment system 22. In response to determining that the difference between the current temperature of the exhaust gas and the predicted temperature of the exhaust gas is above the predetermined threshold, the controller 14 is configured to generate a smoothing command to compensate for the predicted change in the amount of reductant associated with the SCR catalyst 34. Controller 14 is configured to send smoothing commands to exhaust aftertreatment system 22, engine 18, and/or the driveline. For example, the smoothing commands may include commands to increase or decrease reductant dosing and/or increase or decrease exhaust gas temperature to exhaust aftertreatment system 22. In another embodiment, the smoothing command may command engine 18 to increase or decrease the exhaust temperature. In another example, the smoothing command may command a shift of transmission 24 of drive train 20.

Referring now to FIG. 3, a schematic diagram of the controller 14 of the vehicle 10 of FIG. 1 is shown, according to an exemplary embodiment. As shown in FIG. 3, the controller 14 includes a processing circuit 304 having a processor 308 and a memory device 312, a road data circuit 316, an environmental condition circuit 320, a quality estimation circuit 324, an exhaust temperature prediction circuit 328, an exhaust temperature smoothing circuit 332, a feedback control circuit 334, and a communication interface 336. The storage device 312 includes a roadmap 344, the roadmap 344 including one or more routes that the vehicle 10 may travel. The storage device 312 includes road condition information for each of the one or more routes of the roadmap 344. Exemplary road condition information includes road height, road grade, road curvature, road type, speed limit, road construction, bridge, and the like. Generally, the controller 14 is configured to determine a predicted exhaust temperature based on information indicative of upcoming route conditions of the vehicle 10 and current operating conditions of the vehicle 10. The controller 14 is configured to compare the predicted exhaust temperature to the actual exhaust temperature. The controller 14 is configured to generate the smoothing command in response to predicting a peak exhaust temperature when the vehicle 10 encounters an upcoming course condition, as described in more detail below.

In one configuration, the road data circuit 316, the environmental condition circuit 320, the quality estimation circuit 324, the exhaust temperature prediction circuit 328, the exhaust temperature smoothing circuit 332, and the feedback control circuit 334 are implemented as a machine or computer readable medium executable by a processor, such as the processor 308. As described herein and for other purposes, a machine-readable medium facilitates the performance of certain operations to enable the receipt and transmission of data. For example, a machine-readable medium may provide instructions (e.g., commands) to, for example, retrieve data. In this regard, the machine-readable medium may include programmable logic that defines a data acquisition frequency (or data transmission). The computer readable medium may include code that may be written in any programming language, including but not limited to Java, and the like, and any conventional procedural programming language, such as the "C" programming language or similar programming languages. The computer readable program code may be executed on one processor or on multiple remote processors. In the latter case, the remote processors may be interconnected by any type of network (e.g., a CAN bus).

In another configuration, the road data circuit 316, the environmental condition circuit 320, the quality estimation circuit 324, the exhaust temperature prediction circuit 328, the exhaust temperature smoothing circuit 332, and the feedback control circuit 334 may be embodied as one or more circuit components including, but not limited to, processing circuits, network interfaces, peripherals, input devices, output devices, sensors, and the like. In some embodiments, the road data circuit 316, the environmental condition circuit 320, the quality estimation circuit 324, the exhaust temperature prediction circuit 328, the exhaust temperature smoothing circuit 332, and the feedback control circuit 334 may take the form of one or more of the following: analog circuits, electronic circuits (e.g., Integrated Circuits (ICs), discrete circuits, system on a chip (SOC) circuits, microcontrollers), telecommunication circuits, hybrid circuits, and any other type of "circuit". In this regard, the road data circuit 316, the environmental condition circuit 320, the quality estimation circuit 324, the exhaust temperature prediction circuit 328, the exhaust temperature smoothing circuit 332, and the feedback control circuit 334 may include any type of components to implement or facilitate the operations described herein. For example, the circuits described herein may include one OR more transistors, logic gates (e.g., NAND, AND, NOR, OR, XOR, NOT, XNOR), resistors, multiplexers, registers, capacitors, inductors, diodes, wiring, AND the like). The road data circuit 316, the environmental condition circuit 320, the quality estimation circuit 324, the exhaust temperature prediction circuit 328, the exhaust temperature smoothing circuit 332, and the feedback control circuit 334 may also include programmable hardware devices such as field programmable gate arrays, programmable array logic, programmable logic devices, and the like. The road data circuit 316, the environmental condition circuit 320, the quality estimation circuit 324, the exhaust temperature prediction circuit 328, the exhaust temperature smoothing circuit 332, and the feedback control circuit 334 may include one or more memory devices that store instructions that are executable by the processor(s) of the road data circuit 316, the environmental condition circuit 320, the quality estimation circuit 324, the exhaust temperature prediction circuit 328, the exhaust temperature smoothing circuit 332, and the feedback control circuit 334. The one or more storage devices and the processor(s) may have the same definitions as provided below with respect to storage device 312 and processor 308. In some hardware unit configurations, the road data circuit 316, the environmental condition circuit 320, the quality estimation circuit 324, the exhaust temperature prediction circuit 328, the exhaust temperature smoothing circuit 332, and the feedback control circuit 334 may be geographically dispersed at various locations in the vehicle. Optionally and as shown, the road data circuit 316, the environmental condition circuit 320, the quality estimation circuit 324, the exhaust temperature prediction circuit 328, the exhaust temperature smoothing circuit 332, and the feedback control circuit 334 may be embodied on or within a single unit/housing, shown as the controller 14.

In the example shown, the controller 14 includes a processing circuit 304 having a processor 308 and a storage device 312. The processing circuit 304 may be constructed or configured to execute or implement the instructions, commands, and/or control processes described herein with respect to the road data circuit 316, the environmental condition circuit 320, the quality estimation circuit 324, the exhaust temperature prediction circuit 328, the exhaust temperature smoothing circuit 332, and the feedback control circuit 334. The depicted configuration represents the road data circuit 316, the environmental condition circuit 320, the quality estimation circuit 324, the exhaust temperature prediction circuit 328, the exhaust temperature smoothing circuit 332, and the feedback control circuit 334 as machines or computer readable media. However, as noted above, this illustration is not intended to limit other embodiments contemplated by the present disclosure in which the road data circuit 316, the environmental condition circuit 320, the quality estimation circuit 324, the exhaust temperature prediction circuit 328, the exhaust temperature smoothing circuit 332, and the feedback control circuit 334, or at least one of the road data circuit 316, the environmental condition circuit 320, the quality estimation circuit 324, the exhaust temperature prediction circuit 328, the exhaust temperature smoothing circuit 332, and the feedback control circuit 334 are configured as a hardware unit. All such combinations and variations are intended to fall within the scope of the present disclosure.

Processor 308 may be implemented as one or more general-purpose processors, Application Specific Integrated Circuits (ASICs), one or more Field Programmable Gate Arrays (FPGAs), Digital Signal Processors (DSPs), a set of processing components, or other suitable electronic processing components. In some embodiments, one or more processors may be shared by multiple circuits (e.g., the road data circuit 316, the environmental condition circuit 320, the quality estimation circuit 324, the exhaust temperature prediction circuit 328, the exhaust temperature smoothing circuit 332, and the feedback control circuit 334 may include or otherwise share the same processor, which in some example embodiments may execute instructions stored or otherwise accessed via different regions of memory). Alternatively or additionally, one or more processors may be configured to perform or otherwise perform certain operations independently of one or more co-processors. In other example embodiments, two or more processors may be coupled by a bus to enable independent, parallel, pipelined, or multithreaded instruction execution. All such variations are intended to fall within the scope of the present disclosure.

The storage device 312 (e.g., RAM, ROM, flash memory, hard disk memory) may store data and/or computer code that facilitate the various methods described herein. Storage device 312 may be communicatively connected to processor 308 to provide computer code or instructions to processor 308 to perform at least some of the processes described herein. Further, the storage device 312 may be or include tangible non-transitory volatile memory or non-volatile memory. Accordingly, storage device 312 may include database components, object code components, script components, or any other type of information structure for supporting the various activities and information structures described herein.

The communication interface 336 may include wired and/or wireless interfaces (e.g., jacks, antennas, transmitters, receivers, transceivers, wired terminals) for data communication with various systems, devices, or networks configured to support both on-board communication (e.g., between or within components of a vehicle) and off-board communication (e.g., communication with a remote server). For example, the communication interface 336 may include an ethernet card and port for sending and receiving data via an ethernet-based communication network and/or a Wi-Fi transceiver for communicating via a wireless communication network. The communication interface 336 may be configured to communicate via a local or wide area network (e.g., the internet) and may use various communication protocols (e.g., IP, LON, bluetooth, ZigBee, radio, cellular, near field communication).

The communication interface 336 of the controller 14 may facilitate communication between or within the controller 14 and one or more components of the vehicle 10 (e.g., the engine 18, the transmission 24, the exhaust aftertreatment system 22, the

NOx sensors

52, 58, the

temperature sensors

54, 60, the engine speed sensor 62, the humidity sensor 64, the external temperature sensor 68, the weight sensor 72). Communication between or within the controller 14 and the vehicle components may be via any number of wired or wireless connections (e.g., any standard under IEEE 802). For example, the wired connection may include a serial cable, a fiber optic cable, a CAT5 cable, or any other form of wired connection. In contrast, the wireless connection may include the Internet, Wi-Fi, cellular, Bluetooth, ZigBee, radio, and so on. In one embodiment, a Controller Area Network (CAN) bus provides for the interaction of signals, information, and/or data. The CAN bus may include any number of wired and wireless connections that provide for the exchange of signals, information, and/or data. The CAN bus may include a Local Area Network (LAN) or a Wide Area Network (WAN), or may be connected to an external computer (e.g., through the internet using an internet service provider).

The road data circuit 316 is configured to receive information indicative of the location of the vehicle 10 by wireless communication with the (GPS) 204. The road data circuit 316 is configured to identify a location of the vehicle 10 relative to a roadmap 344 stored in the memory device 312. The roadmap 344 includes road conditions for one or more routes that the vehicle 10 may travel. Exemplary road conditions include road height, road grade, road curvature, road type, speed limit, road construction, and the like. In some embodiments, the road data circuit 316 may be configured to receive information from the operator I/O device 76 indicative of the operator-selected route. In other embodiments, the road data circuit 316 may be configured to determine the route based on the location of the vehicle 10 received from the GPS204 and information indicative of the direction of travel of the vehicle 10. After determining the location of the vehicle 10 on the roadmap 344, the road data circuit 316 is configured to retrieve upcoming road conditions a predetermined distance ahead of the vehicle 10 from the roadmap 344. In some embodiments, the predetermined distance may be one-half mile, one mile, five miles, ten miles, and so forth. In other embodiments, the road data circuit 316 is configured to determine upcoming road conditions from the route look-ahead system 78.

The environmental condition circuit 320 is configured to receive information indicative of one or more upcoming environmental conditions of the vehicle 10. Exemplary upcoming environmental conditions include humidity, temperature, wind speed, time of day, precipitation, etc. The environmental condition circuit 320 is configured to receive information indicative of upcoming environmental conditions of the vehicle 10 via the communication interface 336a (e.g., the communication interface 336 may receive signals indicative of upcoming route conditions through wireless communication with the GPS204, weather server 208, etc.). In such embodiments, the environmental condition circuit 320 may receive information indicative of the upcoming environmental conditions of the vehicle 10 from the weather server 208, dispatch server, other sensors in front of the vehicle 10 along the route of the vehicle 10, and the like. In some embodiments, the ambient condition circuit 320 is configured to receive information indicative of the current ambient condition of the vehicle 10 from one or more sensors, such as the humidity sensor 64, the external temperature sensor 68, and/or other ambient sensors. In such embodiments, the environmental condition circuitry 320 may be configured to compare the current environmental condition with the upcoming environmental condition.

The mass estimation circuit 324 is configured to determine the mass of the vehicle 10 based on the information indicative of the weight of the vehicle 10. For example, the mass estimation circuit 324 may receive information indicative of the weight of the vehicle 10 from one or more weight sensors 72. In some arrangements, the weight sensors may be located on the vehicle 10 (e.g., on the axles or elsewhere of the vehicle 10 and/or a cargo trailer or container coupled to the vehicle 10). In some embodiments, one or more weight sensors 72 may be embedded in a portion of the roadway or load zone occupied by the vehicle 10 and may be configured to send information indicative of the weight of the vehicle 10 to the quality estimation circuit 324 via the communication interface 336.

Exhaust temperature prediction circuit 328 is configured to receive information from sensors 52-62 indicative of current vehicle operating conditions. The current vehicle operating conditions may include the mass of the vehicle 10, the current engine speed, the current engine load, the current temperature of the exhaust gas produced by the engine 18, the current NOx concentration at or near the inlet of the SCR catalyst 34, and/or the current NOx concentration at or near the outlet of the SCR catalyst 34. The engine 18 is operated at higher torque and/or speed to produce higher engine loads, which increases the temperature of the exhaust gas produced by the engine 18. Since the exhaust gas flows through the SCR catalyst 34, the higher temperature exhaust gas increases the temperature of the SCR catalyst 34. In some embodiments, the exhaust temperature prediction circuit 328 is configured to determine the engine load based on the mass of the vehicle 10, the speed of the vehicle 10, and upcoming route conditions. As used herein, the phrase "route condition" refers to road conditions and/or upcoming environmental conditions. Exhaust temperature prediction circuit 328 is configured to predict an upcoming speed and/or an upcoming torque of engine 18 based on information indicative of one or more of upcoming route conditions and current vehicle operating conditions. In some embodiments, the exhaust temperature prediction circuit 328 may predict the upcoming speed and/or torque of the engine 18 based on algorithms, mathematical models, look-up tables, stored data from similar types of vehicles traveling under similar operating conditions (e.g., vehicle load, ambient conditions) in the area, and the like. Exhaust temperature prediction circuit 328 is configured to predict an upcoming exhaust temperature based on the predicted upcoming speed and/or torque of engine 18. In some embodiments, the exhaust temperature prediction circuit 328 may predict the exhaust temperature based on an algorithm, a mathematical model, a look-up table, or the like.

For example, the exhaust temperature prediction circuit 328 may include one or more mathematical models configured to predict the exhaust temperature as a function of engine load and/or engine speed. Exhaust temperature prediction circuit 328 may input the predicted engine load and/or the predicted engine speed into a mathematical model and determine the predicted engine temperature via the mathematical model. In another example, the memory device 312 may include a look-up table that correlates engine load and/or engine speed to exhaust temperature. The exhaust temperature prediction circuit 328 may determine the predicted exhaust temperature based on the predicted engine load and/or the predicted engine speed from the lookup table.

In some embodiments, storage device 312 or an external computing system such as a cloud may include experimental data indicative of the effect of one or more environmental conditions on exhaust temperature. For example, a vehicle layout (e.g., same or similar electric motor, transmission, weight, aerodynamic profile, etc.) similar to a vehicle traveling over various route conditions (e.g., altitude, etc.) may track exhaust temperature changes under these conditions and various weather conditions (e.g., snow, hail, etc.). This data can be used to form a look-up table for similarly constructed vehicles. The lookup table may be used to predict temperature peaks or non-peaks under various weather conditions and route conditions. For example, the one or more environmental conditions may include precipitation. The environmental condition circuit 320 may receive information indicative of upcoming precipitation, such as rain, snow, sleet, hail, and the like. The exhaust temperature prediction circuit 328 may use a lookup table to determine the effect of the upcoming precipitation on the exhaust temperature. In such an example, the exhaust temperature prediction circuit 328 may determine, based on the lookup table, that the upcoming sensation may decrease the exhaust temperature by approximately a predetermined amount.

In another example, the one or more environmental conditions may include humidity. The ambient condition circuit 320 may receive information indicative of the upcoming humidity. The exhaust temperature prediction circuit 328 may determine the effect of the upcoming humidity on the exhaust temperature based on the predicted engine load, the predicted engine speed, and/or the predicted road conditions and the look-up table. In such an example, exhaust temperature prediction circuit 328 may determine, based on the lookup table, that the imminent humidity increase may decrease the exhaust temperature by an amount and decrease the predicted exhaust temperature by the amount. In another example, exhaust temperature prediction circuit 328 may increase the exhaust temperature by a predetermined amount and increase the predicted exhaust temperature by that amount based on a lookup table determining that humidity is about to decrease.

In another example, the one or more environmental conditions may include an upwind. As used herein, headwind is wind that blows in a direction substantially opposite to the direction of travel of the vehicle 10. The headwind may increase the engine load required to operate engine 18 at an operator-specified speed to offset the effect of headwind pushing toward vehicle 10. The environmental condition circuitry 320 may receive or otherwise determine information indicative of an upcoming headwind. The exhaust temperature prediction circuit 328 may determine the effect of the upcoming headwind on the exhaust temperature based on the predicted engine load, the predicted engine speed, and/or the predicted road conditions and the look-up table. In such an example, exhaust temperature prediction circuit 328 may determine, based on the lookup table, that the headwind is about to increase the exhaust temperature by a predetermined amount and increase the predicted exhaust temperature by that amount. In another example, exhaust temperature prediction circuit 328 may determine that the headwind is imminent may decrease the exhaust temperature by a predetermined amount and decrease the predicted exhaust temperature by that amount based on a lookup table.

In another example, the one or more environmental conditions may include downwind. As used herein, downwind is wind that is blowing in substantially the same direction as the travel of the vehicle 10. Downwind may reduce the engine load required to operate engine 18 at an operator-specified speed because downwind may propel vehicle 10 in the direction of travel. The environmental condition circuit 320 may receive information indicating an upcoming tailwind. The exhaust temperature prediction circuit 328 may determine the effect of the upcoming tailwind on the exhaust temperature based on the predicted engine load, the predicted engine speed, and/or the predicted road conditions and the look-up table. In such an example, the exhaust temperature prediction circuit 328 may determine, based on the lookup table, that the downwind is about to increase may decrease the exhaust temperature by a predetermined amount (e.g., based on experimental data) and decrease the predicted exhaust temperature by that amount. In another example, the exhaust temperature prediction circuit 328 may increase the exhaust temperature by a predetermined amount and increase the predicted exhaust temperature by that amount based on a lookup table determining that downwind is about to decrease.

Exhaust temperature smoothing circuit 332 is configured to receive the predicted exhaust temperature from exhaust temperature prediction circuit 328. The exhaust temperature smoothing circuit 332 is configured to determine the likelihood that an exhaust temperature spike may occur when the vehicle 10 encounters an upcoming course condition based on the current exhaust temperature and the predicted exhaust temperature. As used herein, "peak value" refers to a rapid increase and/or decrease in exhaust temperature relative to the current exhaust temperature that changes the temperature of the SCR catalyst 34. Since the absorption of the SCR catalyst 34 by the reductant is temperature dependent, a peak in exhaust gas temperature can cause a sharp change in the amount of reductant bound to the SCR catalyst 34 (and thus in the exhaust gas). For example, when a temperature spike causes an increase in exhaust temperature, reductant is released from the SCR catalyst 34 as the temperature increases. This may result in an excess of reductant in the exhaust gas relative to the amount of NOx in the exhaust gas, which may result in reductant slip. In another example, when a temperature spike causes a decrease in exhaust temperature, the SCR catalyst 34 absorbs reductant from the exhaust as the temperature decreases, which may result in an excess amount of NOx in the exhaust relative to the amount of reductant in the exhaust, which may result in NOx emissions.

The exhaust temperature smoothing circuit 332 may determine a temperature difference between the current temperature of the exhaust gas and the predicted temperature of the exhaust gas. The exhaust temperature smoothing circuit 332 is configured to determine the likelihood of an exhaust temperature spike occurring when the vehicle 10 encounters an upcoming route condition by comparing the temperature difference to a difference threshold (e.g., value, etc.). Since the reductant in combination with the SCR catalyst 34 is temperature dependent, the exhaust temperature smoothing circuit 332 may be configured to predict changes in ammonia nitrogen oxide ratio (ANR) due to temperature differences based on algorithms, mathematical models, look-up tables, and the like.

In response to determining that the temperature difference is equal to or below the difference threshold, the exhaust temperature smoothing circuit 332 is configured to determine that a temperature spike is unlikely. In response to determining that a temperature spike is unlikely to occur, the exhaust temperature smoothing circuit 332 is configured to command the engine 18 to generate a predicted upcoming engine speed and/or torque that is required based on the upcoming route condition determination.

In response to determining that the temperature difference is above the difference threshold, the exhaust temperature smoothing circuit 332 is configured to determine that a temperature spike is possible. Exhaust temperature smoothing circuit 332 is configured to determine a smoothing command for one or more components of engine 18, transmission 20, and/or exhaust aftertreatment system 22. The smoothing command is configured to compensate for predicted changes in the amount of reductant associated with the SCR catalyst 34 due to temperature spikes. As used herein, the phrase "compensating" refers to mitigating its effects. For example, the smoothing command may compensate for predicted changes in reductant associated with the SCR catalyst 34 by changing exhaust temperature and/or by changing reductant dosage by the reductant doser 40. The smoothing command may include one or more of: changing a speed of the engine 18, changing one or more gears of the transmission 24, changing an amount and/or frequency of reductant dosing, changing an amount and/or frequency of fuel injection, and the like. In some embodiments, the smoothing command is configured to end after a predetermined period of time and/or after the vehicle 10 has traveled a predetermined distance. In some cases, the smoothing command is configured to reduce the temperature spike based on the temperature difference and the upcoming route condition. For example, the smoothing command may extend the change in engine speed and/or engine load predicted to cause the temperature spike over a larger period of time, thereby reducing the magnitude of the temperature spike (e.g., the difference between the current exhaust temperature and the predicted exhaust temperature) and causing the temperature change to occur more slowly, thereby reducing the likelihood of reductant slip or tailpipe NOx emissions. In some cases, the smoothing command is configured such that mitigating action should be taken to compensate for the effect of the temperature spike on the reductant content in the exhaust. For example, the smoothing command may be configured to command one or more reductant dosers 40 to stop dosing or reduce dosing of reductant at approximately the same time and/or vehicle location along the route of the temperature peak predicted to result in an increase in exhaust temperature, thereby reducing the likelihood of reductant slip or exhaust NOx emissions. In such embodiments, the exhaust temperature smoothing circuit 332 may be configured to predict changes in ANR due to temperature spikes. The exhaust temperature smoothing circuit 332 may be configured to determine an amount of reductant released (e.g., for a temperature spike due to an increase in exhaust temperature) or an amount of reductant absorbed (e.g., for a temperature spike due to a decrease in exhaust temperature). The exhaust temperature smoothing circuit 332 may be configured to determine an amount by which reductant dosing changes (e.g., increases, decreases, stops, or restarts) based on predicted changes in ANR.

Because the exhaust temperature smoothing circuit 332 is configured to determine the smoothing command based on the temperature difference, the exhaust temperature smoothing circuit 332 determines the smoothing command before the vehicle 10 encounters an upcoming road and/or environmental condition that is predicted to result in a temperature spike that occurs before or substantially simultaneously with the predicted temperature spike. This prevents or reduces ANR changes in the exhaust gas due to temperature peaks, thereby reducing reductant slip and/or NOx emissions due to temperature peaks relative to the vehicle 10 that are controlled based on current route conditions.

In embodiments where the temperature smoothing commands include one or more of changing a speed of the engine 18, changing one or more gears of the transmission 24, changing an amount and/or frequency of fuel injection, etc., the exhaust temperature smoothing circuit 332 may be configured to generate one or more temperature smoothing commands such that the predicted exhaust temperature is within a predetermined range of the current exhaust temperature. This allows some exhaust temperature fluctuations but still prevents or possibly prevents exhaust temperature spikes. In such embodiments, one or more temperature smoothing commands may allow for predicting fluctuations in exhaust temperature above a predefined low exhaust temperature and below a predetermined high exhaust temperature relative to a current exhaust temperature. The predetermined low and high exhaust temperatures may define a range of acceptable exhaust temperatures and be specific to a current or predicted exhaust temperature (e.g., acceptable limits for exhaust temperatures that are not considered temperature peaks relative to the current or predicted exhaust temperature). In such embodiments, the exhaust temperature smoothing circuit 332 may be configured to determine a temperature smoothing command to change the speed of the engine 18, to change one or more gears of the transmission 24, and/or to change the amount and/or frequency of fuel injection based on experimental data to bring the predicted exhaust temperature within a predetermined range of the current exhaust temperature. The experimental data may be used to generate one or more look-up tables, equations, etc. stored in the memory device 312 or an external computing system (e.g., cloud) of the vehicle 10 for establishing acceptable temperature limits for a smoothed exhaust temperature given a current or predicted exhaust temperature relative to upcoming events that may result in temperature spikes (e.g., hills, etc.).

In an example embodiment, the operator may be driving the vehicle 10 at the current vehicle speed. Exhaust temperature smoothing circuit 332 may receive the predicted exhaust temperature from exhaust temperature prediction circuit 328. The exhaust temperature smoothing circuit 332 may then determine a temperature difference between the current exhaust temperature and the predicted exhaust temperature and compare the temperature difference to a difference threshold. In response to determining that the temperature difference is above the difference threshold, the exhaust temperature smoothing circuit 332 determines that a temperature spike may occur and determines a temperature smoothing command to reduce the likelihood of the temperature spike. The temperature difference may be above a difference threshold due to a predicted exhaust temperature or an increase or decrease relative to the current exhaust temperature.

Exhaust temperature smoothing circuit 332 may generate a temperature smoothing command that includes one or more commands to drive train system 20. For example, the temperature smoothing command may include a command to shift the transmission 24 to a lower gear. Shifting the transmission 24 to a lower gear may increase the temperature of the exhaust without a substantial change in temperature speed. In another example, the temperature smoothing command may include a command to shift the transmission 24 to a higher gear. Shifting the transmission 24 to a higher gear may reduce the temperature of the exhaust without a substantial change in temperature speed. In some embodiments, such as embodiments in which the transmission 24 is an automatic transmission, the temperature smoothing command automatically changes the gear of the transmission 24. In other embodiments, the temperature smoothing command may display a command to the operator via the operator I/O device 76 to change the gear of the transmission 24.

The feedback control circuit 334 is configured to receive information indicative of engine outlet NOx from the second NOx sensor 58. The feedback control circuit 334 is configured to compare the information indicative of engine outlet NOx to a predetermined engine outlet NOx threshold. The engine-out NOx threshold is an upper limit value or range of values for acceptable engine-out NOx. In certain embodiments, the engine-out NOx threshold range is 400-600 mg/kWh NOx as defined in the Chinese NS VI. The feedback control circuit 334 is configured to generate the NOx mitigation command in response to determining that the engine outlet NOx is equal to or above a predetermined engine outlet NOx threshold. In some embodiments, the feedback control circuit 334 is configured to generate the NOx mitigation command in response to determining that the engine outlet NOx has been equal to or above the predetermined engine outlet NOx threshold for a predetermined period of time. In some embodiments, the feedback control circuit 334 is configured to display a fault notification to the operator via the operator I/O device 76 in response to determining that the engine outlet NOx has been equal to or above the predetermined engine outlet NOx threshold for a predetermined period of time. The NOx mitigation commands are configured to alter operation of one or more components of the engine system 12 and/or the exhaust aftertreatment system 22 to reduce the amount of engine-out NOx. For example, the NOx mitigation command may reduce the engine speed to reduce the amount of NOx in the exhaust gas entering the exhaust aftertreatment system 22. In some embodiments, feedback control circuit 334 is configured to record the amount of time that engine outlet NOx has risen above a predetermined engine outlet NOx threshold.

The feedback control circuit 334 is configured to receive information indicative of the engine outlet reductant concentration from the second NOx sensor 58. The feedback control circuit 334 is configured to compare information indicative of the engine outlet reductant concentration to a predetermined reductant slip threshold. The reductant slip threshold is an upper limit or range of values for acceptable engine outlet reductant concentration. In some embodiments, the reductant slip threshold is substantially 10ppm, as defined in chinese NS VI. The feedback control circuit 334 is configured to generate a reductant slip mitigation command in response to determining that the engine outlet reductant concentration is equal to or above a predetermined reductant slip threshold. In some embodiments, feedback control circuit 334 is configured to generate the reductant slip mitigation command in response to determining that the engine outlet reductant concentration has been equal to or above a predetermined reductometer slip threshold for a predetermined period of time. In some embodiments, the feedback control circuit 334 is configured to display a fault notification to the operator via the operator I/O device 76 in response to determining that the engine outlet reductant concentration has been equal to or above the predetermined reductant slip threshold for a predetermined period of time. The reductant slip mitigation command is configured to alter operation of more components of engine system 12 and/or exhaust aftertreatment system 22 to reduce the concentration of reductant in the exhaust gas flow. For example, the NOx mitigation command may reduce a speed or load of the engine 18 to produce a reduction in the temperature of the exhaust gas entering the exhaust aftertreatment system 22 and/or command the reductant doser 40 to reduce or stop reductant dosing. In some embodiments, feedback control circuit 334 is configured to record an amount of time that the engine outlet reductant concentration has been above a predetermined reductant slip threshold.

FIG. 4 illustrates an exemplary method 400 for controlling engine 18 to reduce the likelihood of temperature spikes in exhaust gas produced by engine 18. At process 404, the road data circuit 316 receives information from the GPS204 indicating the location of the vehicle 10. At process 408, the road data circuit 316 identifies the location of the vehicle 10 relative to the roadmap 344 stored to the memory device 312. The route pattern 344 includes road condition information of one or more routes that the vehicle 10 can travel. Exemplary road condition information includes road grade, road type, speed limit, etc. In some embodiments, the road data circuit 316 may receive information from the operator I/O device 76 indicating the operator-selected route. In other embodiments, the road data circuit 316 may determine the route based on the location of the vehicle 10 received from the GPS204 and information indicative of the direction of travel of the vehicle 10. At process 412, after determining the location of the vehicle 10 on the roadmap 344, the road data circuit 316 retrieves upcoming road conditions a predetermined distance ahead of the vehicle 10 from the roadmap 344. In some embodiments, the predetermined distance may be one-half mile, one mile, five miles, ten miles, and so forth.

At process 416, the environmental condition circuit 320 receives information indicative of one or more upcoming environmental conditions of the vehicle 10. Exemplary upcoming environmental conditions include humidity, temperature, wind speed, time of day, precipitation, etc. In some embodiments, the environmental condition circuit 320 receives information indicative of an upcoming environmental condition of the vehicle 10 from one or more sensors, such as the humidity sensor 64, the outside temperature sensor 68, and/or other environmental sensors. In other embodiments, the environmental condition circuit 320 receives information indicative of an upcoming environmental condition of the vehicle 10 via the communication interface 336.

At process 420, the mass estimation circuit 324 determines the mass of the vehicle 10 based on the information indicative of the weight of the vehicle 10. For example, the mass estimation circuit 324 may receive information indicative of the weight of the vehicle 10 from one or more weight sensors 72.

At process 424, exhaust temperature prediction circuit 328 receives information from sensors 52-60 indicative of current vehicle operating conditions. The current vehicle operating conditions may include the mass of the vehicle 10, the current engine speed, the current engine load, the current temperature of the exhaust gas produced by the engine 18, the current NOx concentration at or near the inlet of the SCR catalyst 34, and/or the current NOx concentration at or near the outlet of the SCR catalyst 34. In some embodiments, the exhaust temperature prediction circuit 328 determines the engine load based on the mass of the vehicle 10, the speed of the vehicle 10, and upcoming route conditions. At process 428, the exhaust temperature prediction circuit 328 predicts an upcoming speed and/or an upcoming torque of the engine 18 based on the information indicative of the one or more upcoming route conditions and the one or more current vehicle operating conditions. In some embodiments, the exhaust temperature prediction circuit 328 predicts the upcoming speed and/or torque of the engine 18 based on algorithms, mathematical models, look-up tables, stored data from similar types of vehicles traveling under similar operating conditions (e.g., vehicle load, ambient conditions) in the area, and the like. At process 432, exhaust temperature prediction circuit 328 predicts an upcoming exhaust temperature based on the predicted upcoming speed and/or torque of engine 18. In some embodiments, the exhaust temperature prediction circuit 328 predicts the exhaust temperature based on an algorithm, a mathematical model, a look-up table, or the like.

Exhaust temperature smoothing circuit 332 receives the predicted exhaust temperature from exhaust temperature prediction circuit 328. At process 436, the exhaust temperature smoothing circuit 332 determines a temperature difference between the current temperature of the exhaust gas and the predicted temperature of the exhaust gas. At process 440, the exhaust temperature smoothing circuit 332 determines the likelihood of an exhaust temperature spike when the vehicle 10 encounters an upcoming course condition by comparing the temperature difference to a difference threshold.

In process 444, in response to determining that a temperature spike is unlikely to occur, the exhaust temperature smoothing circuit 332 commands the engine 18 to produce a predicted upcoming engine speed and/or torque determined based on the upcoming route conditions.

At process 448, in response to determining that a temperature spike may occur, the exhaust temperature smoothing circuit 332 determines a smoothing command to reduce the temperature spike based on the temperature difference and the upcoming route condition. The smoothing command is configured to compensate for predicted changes in the amount of reductant associated with the SCR catalyst 34 due to temperature spikes. The smoothing command may include one or more of: changing a speed of the engine 18, changing a gear of the transmission 24, changing (e.g., increasing, decreasing, stopping, or resuming) an amount and/or frequency of the reductant doser 40, and/or the like. At process 452, the exhaust temperature smoothing circuit 332 transmits a smoothing command to one or more of the engine 18, the transmission system 20 (e.g., the transmission 24), the exhaust aftertreatment system 22 (e.g., the reductant doser 40), and the like.

In process 456, the feedback control circuit 334 receives information indicative of engine outlet NOx from the second NOx sensor 58. At process 460, feedback control circuitry 334 compares the information indicative of engine outlet NOx to a predetermined engine outlet NOx threshold. In response to determining that the engine outlet NOx is below the predetermined engine outlet NOx threshold, feedback control circuitry 334 returns to process 456. In process 464, the feedback control circuit 334 generates a NOx mitigation command in response to determining that the engine outlet NOx is equal to or above the predetermined engine outlet NOx threshold. In some embodiments, the feedback control circuit 334 generates the NOx mitigation command in response to determining that the engine outlet NOx has been above the predetermined engine outlet NOx threshold for a predetermined period of time. The NOx mitigation command alters operation of one or more components of the engine system 12 and/or the exhaust aftertreatment system 22 to reduce the amount of engine-out NOx. At process 468, the feedback control circuit 334 transmits a NOx mitigation command to the engine system 12 and/or the exhaust aftertreatment system 22. The feedback control circuit 334 then returns to process 456.

Fig. 5 is a time-height graph illustrating vehicle 10 traveling along a portion of an example route 500. The route 500 includes a hill 504 having an uphill portion 508 and a downhill portion 512. FIG. 6 is a graph of time versus temperature illustrating exhaust temperatures of the vehicle 10 (dashed line) and a conventional vehicle (black line) as the vehicle 10 and the conventional vehicle travel along a portion of the route 500 shown in FIG. 5. As used herein, the phrase "conventional vehicle" refers to a vehicle that does not include the systems and methods described herein.

As the vehicle 10 approaches the hill 504, the road data circuit 316 receives information from the GPS204 indicating the location of the vehicle 10. The road data circuit 316 identifies the location of the vehicle 10 relative to a roadmap 344 stored to the memory device 312. The road data circuit 316 retrieves upcoming road conditions a predetermined distance ahead of the vehicle 10 from the roadmap 344. In the illustrated example, the upcoming road condition may include indicating that the vehicle 10 is approaching a hill 504, indicating a distance between a current location of the vehicle 10 and the hill 504, indicating a road grade of the uphill portion 508, indicating a current height of the vehicle 10, indicating a height of a top of the hill 504, and so forth. Exhaust temperature prediction circuit 328 receives information from sensors 52-60 indicative of current vehicle operating conditions. The exhaust temperature prediction circuit 328 predicts an upcoming speed and/or an upcoming torque of the engine 18 based on upcoming road conditions, upcoming ambient conditions (e.g., determined by the ambient condition circuit 320), and one or more current operating conditions in the vehicle. For example, the exhaust temperature prediction circuit 328 predicts the upcoming speed and/or upcoming torque of the engine 18 based on the road conditions of the upcoming uphill portion 508, upcoming ambient conditions, and as the vehicle is operating conditions, as the vehicle 10 travels along the uphill portion 508.

In this example, the exhaust temperature prediction circuit 328 determines that there may be a temperature spike (e.g., a rapid temperature increase) when the vehicle 10 is traveling along the uphill portion 508 (e.g., using the process 424 and 452). The exhaust temperature smoothing circuit 332 determines a smoothing command to reduce the temperature peak. In the examples shown in fig. 5 and 6, the smoothing commands include commands to increase the speed of the engine 18 and/or to increase the torque of the engine 18. Although not shown in fig. 5 or 6, the smoothing commands may also include commands to stop or reduce dosing of reductant to compensate for reductant released from SCR catalyst 34 as exhaust temperature increases. As indicated by the dashed lines in FIG. 6, the smoothing command causes the engine 18 to begin operating at a higher temperature (e.g., increased speed and/or torque) before the vehicle 10 begins to travel along the uphill portion 508. As the vehicle 10 approaches the uphill portion 508, the exhaust temperature of the vehicle 10 is higher than that of a conventional vehicle (solid line), as indicated by arrow 604. As the vehicle 10 and the conventional vehicle climb the uphill portion 508 of the hill 504, the exhaust temperature of the vehicle 10 and the exhaust temperature of the conventional vehicle both increase, as indicated by arrow 608. However, as shown in fig. 6, the exhaust temperature of the vehicle 10 gradually increases as it climbs the uphill portion 508 and there is no temperature peak. Conversely, as the conventional vehicle climbs the uphill portion 508, the exhaust temperature of the conventional vehicle increases rapidly and has a temperature spike, as indicated by arrow 612. In the example shown in fig. 6, the increase in exhaust gas temperature when the conventional vehicle climbs the uphill portion 508 is more than twice the increase in exhaust gas temperature when the vehicle 10 climbs the uphill portion 508.

Returning to fig. 5, when the vehicle 10 is climbing a hill, the controller 14 continues to receive information from the GPS204 indicating the location of the vehicle 10, identify the location of the vehicle 10 relative to the roadmap 344, and retrieve upcoming road conditions a predetermined distance ahead of the vehicle 10 from the roadmap. As the vehicle 10 approaches the top of the hill 504, upcoming road conditions may indicate that the vehicle 10 is approaching the downhill portion 512, the distance between the current location of the vehicle 10 and the downhill portion 512, the road grade of the downhill portion 512, the current height of the vehicle 10, the top height of the hill 504, and so forth. Exhaust temperature prediction circuit 328 receives information from sensors 52-60 indicative of current vehicle operating conditions. The exhaust temperature prediction circuit 328 predicts an upcoming speed and/or an upcoming torque of the engine 18 based on information indicative of one or more of upcoming route conditions and current vehicle operating conditions. For example, when the vehicle 10 is traveling down the downhill portion 512, the exhaust temperature prediction circuit 328 predicts an upcoming speed and/or an upcoming torque of the engine 18 based on road conditions of the upcoming downhill portion 512, upcoming ambient conditions, and when vehicle operating conditions.

In this example, the exhaust temperature prediction circuit 328 determines that the temperature may drop rapidly as the vehicle 10 travels along the downhill portion 512 (e.g., using process 424 and 452). The exhaust temperature smoothing circuit 332 determines a smoothing command to reduce the temperature peak. In the example of fig. 4 and 5, the smoothing command includes a command to gradually reduce the speed of the engine 18 and/or reduce its torque as the vehicle 10 travels along the downhill portion 512. As indicated by the line of arrow 616 in fig. 6, the smoothing command operates the engine 18 (dashed line) at a higher temperature relative to the engine (dashed line) of a conventional vehicle in the latter half of the downhill section 512. This prevents a rapid drop in exhaust temperature as the vehicle 10 travels along the downhill portion 512. Conversely, as indicated by arrow 620, the exhaust temperature of the conventional vehicle increases rapidly and has a temperature spike as the conventional vehicle travels down the downhill portion 512. In the example shown in fig. 6, the increase in exhaust gas temperature when the conventional vehicle climbs the uphill portion 508 is more than twice the increase in exhaust gas temperature when the vehicle 10 climbs the uphill portion 508.

In another example, environmental conditions may affect the temperature of the exhaust. For example, the combustion temperature (and thus the exhaust gas temperature) decreases with increasing humidity. Thus, the road data circuit 316 receives information from the GPS204 indicating the location of the vehicle 10 as the vehicle 10 travels along the route. The ambient condition circuit 320 receives information from the humidity sensor 64 and/or wirelessly communicating with the weather server 208 indicating an impending increase in humidity. Exhaust temperature prediction circuit 328 receives information from sensors 52-60 indicative of current vehicle operating conditions. In this example, the exhaust temperature prediction circuit 328 determines that there may be a temperature spike (e.g., a rapid drop in temperature) when the vehicle 10 enters a location with an increase in humidity (e.g., using the process 424-. The exhaust temperature smoothing circuit 332 determines a smoothing command to reduce the temperature peak. In the examples shown in fig. 4-5, the smoothing commands include commands to increase the speed of the engine 18 and/or increase the torque of the engine 18 to increase the exhaust temperature.

For the purposes of this disclosure, the term "coupled" means that two members are directly or indirectly connected or linked to each other. Such connections may be fixed or movable in nature. For example, a driveshaft of an engine is "coupled" to a representation of a transmission, which represents a movable coupling. Such joining may be achieved with two members or with two members and any additional intermediate members. For example, circuit a being communicatively "coupled" to circuit B may mean that circuit a is in direct communication with circuit B (i.e., without intermediaries) or in indirect communication with circuit B (e.g., through one or more intermediaries).

Although various modules having particular functionality are shown in fig. 3, it should be understood that controller 14 may include any number of circuits for performing the functionality described herein. For example, the activities and functions of

circuitry

316 and 332 may be combined in multiple circuits or as a single circuit. Additional circuitry with additional functionality may be included. In addition, the controller 14 may further control other activities beyond the scope of this disclosure.

As described above and in one configuration, "circuitry" may be implemented in a machine-readable medium for execution by various types of processors, such as processor 308 of fig. 3. For example, executable code may identify circuits that comprise one or more physical or logical blocks of computer instructions, which may, for example, be organized as an object, procedure, or function. Nevertheless, the executables of an identified circuit need not be physically located together, but may comprise disparate instructions stored in different locations which, when joined logically together, comprise the circuit and achieve the stated purpose for the circuit. Indeed, the computer readable program code circuitry may be a single instruction, or many instructions, and may even be distributed over several different code segments, among different programs, and across several memory devices. Similarly, operational data may be identified and illustrated herein within circuitry, and may be embodied in any suitable form and organized within any suitable type of data structure. The operational data may be collected as a single data set, or may be distributed over different locations including over different storage devices, and may exist, at least partially, merely as electronic signals on a system or network.

Although the term "processor" is briefly defined above, the terms "processor" and "processing circuitry" are intended to be broadly construed. In this regard and as noted above, a "processor" may be implemented as one or more general-purpose processors, Application Specific Integrated Circuits (ASICs), Field Programmable Gate Arrays (FPGAs), Digital Signal Processors (DSPs), or other suitable electronic data processing components configured to execute instructions provided by a memory. The one or more processors may take the form of single-core processors, multi-core processors (e.g., dual-core processors, three-core processors, four-core processors), microprocessors, and the like. In some embodiments, the one or more processors may be external to the device, e.g., the one or more processors may be remote processors (e.g., cloud-based processors). Alternatively or additionally, the one or more processors may be internal and/or local to the device. In this regard, a given circuit or component thereof may be deployed locally (e.g., as part of a local computing system) or remotely (e.g., as part of a remote server such as a server-based cloud). To this end, a "circuit" described herein may include components distributed across one or more locations.

Although the diagrams herein may show a particular order and composition of method steps, the order of the steps may differ from what is depicted. For example, two or more steps may be performed simultaneously or partially simultaneously. Also, some method steps performed as separate steps may be combined, steps performed as combined steps may be separated into separate steps, the order of some processes may be reversed or otherwise varied, the nature or number of separate processes may be altered or varied. The order or sequence of any elements or devices may be varied or substituted according to alternative embodiments. All such modifications are intended to be included within the scope of this disclosure as defined in the following claims. Such variations will depend on the machine-readable medium and hardware system chosen and on the choices of the designer. All such variations are within the scope of the present disclosure.

The foregoing description of the embodiments has been presented for purposes of illustration and description. It is not intended to be exhaustive or to limit the disclosure to the precise form disclosed, and modifications and variations are possible in light of the above teachings or may be acquired from this disclosure. The embodiments were chosen and described in order to explain the principles of the disclosure and its practical application to enable one skilled in the art to utilize the disclosure in various embodiments and with various modifications as are suited to the particular use contemplated. Other substitutions, modifications, changes and omissions may be made in the design, operating conditions and arrangement of the embodiments without departing from the scope of the present disclosure as expressed in the appended claims.

Accordingly, the present disclosure may be embodied in other specific forms without departing from its spirit or essential characteristics. The described embodiments are to be considered in all respects only as illustrative and not restrictive. The scope of the disclosure is, therefore, indicated by the appended claims rather than by the foregoing description. All changes which come within the meaning and range of equivalency of the claims are to be embraced within their scope.

Claims

1. A system, characterized in that the system comprises:

an exhaust aftertreatment system including a Selective Catalytic Reduction (SCR) catalyst; and

a controller configured to:

receiving information indicative of an upcoming route condition;

receiving information indicative of a current vehicle operating condition;

determining a predicted exhaust temperature of the vehicle at the upcoming location based on the information indicative of the upcoming route condition and the current vehicle operating condition;

receiving information indicative of a current exhaust temperature;

determining a difference between the current exhaust temperature and the predicted exhaust temperature;

in response to determining that a difference between the current exhaust temperature and the predicted exhaust temperature is above a predetermined threshold, determining a smoothing command; and

controlling a vehicle system based on the smoothing command to compensate for a difference between the current exhaust temperature and the predicted exhaust temperature.

2. The system of claim 1, wherein the information indicative of upcoming route conditions includes one or more of road height, road grade, road curvature, road type, speed limit, humidity, temperature, wind speed, time of day, precipitation.

3. The system of claim 1, wherein the information indicative of the current vehicle operating conditions comprises at least one of: the mass of the vehicle, the current engine speed, the current engine load, the current temperature of the exhaust gas produced by the engine, the current NOx concentration at or near the inlet of the SCR catalyst, or the current NOx concentration at or near the outlet of the SCR catalyst.

4. The system of claim 1, wherein the smoothing command comprises changing a load on an engine of the vehicle to change a temperature of exhaust gas produced by the engine.

5. The system of claim 4, wherein changing the load on the engine comprises changing an engine speed or a gear setting of a transmission coupled to the engine.

6. The system of claim 1, wherein the exhaust aftertreatment system includes one or more reductant dosers configured to provide reductant into the exhaust stream, and the smoothing command is configured to change operation of the one or more reductant dosers.

7. The system of claim 6, wherein the controller is further configured to:

determining a predicted change in an ammonia-to-oxide ratio (ANR) of the exhaust gas based on the difference; and

determining a smoothing command according to the predicted ANR change.

8. An apparatus, characterized in that the apparatus comprises:

a road information circuit configured to receive information indicative of an upcoming route condition;

an exhaust temperature prediction circuit configured to:

receiving information indicative of a current vehicle operating condition;

determining a predicted exhaust temperature based on information indicative of upcoming route conditions and current vehicle operating conditions;

receiving information indicative of a current exhaust temperature;

determining a difference between the current exhaust temperature and the predicted exhaust temperature; and

an exhaust temperature smoothing circuit configured to:

9. The apparatus of claim 8, wherein the information indicative of upcoming route conditions comprises at least one of road height, road grade, road curvature, road type, speed limit, road structure, humidity, temperature, wind speed, time of day, precipitation.

10. The apparatus of claim 8, wherein the information indicative of the current vehicle operating condition comprises: the mass of the vehicle, the current engine speed, the current engine load, the current temperature of the exhaust gas produced by the engine, the current NOx concentration at or near the inlet of the SCR catalyst, or the current NOx concentration at or near the outlet of the SCR catalyst.

11. The apparatus of claim 8, wherein the smoothing command comprises varying a load on the engine to vary a temperature of exhaust gas produced by the engine.

12. The apparatus of claim 11, wherein changing the load on the engine comprises changing an engine speed or a gear setting of a transmission coupled to the engine.

13. The apparatus of claim 8, wherein the exhaust aftertreatment system includes one or more reductant dosers configured to provide reductant into the exhaust stream, and the smoothing command is configured to change operation of the one or more reductant dosers.

14. The apparatus of claim 13, wherein the exhaust temperature smoothing circuit is further configured to:

determining a predicted change in an ammonia nitrogen oxide ratio (ANR) of the exhaust based on the difference; and

determining a smoothing command according to the predicted ANR change.

15. A method, characterized in that the method comprises:

receiving, by a controller of a vehicle, information indicative of an upcoming route condition;

receiving, by a controller, information indicative of a current vehicle operating condition;

determining, by the controller, a predicted exhaust temperature based on the information indicative of the upcoming route condition and the current vehicle operating condition;

receiving, by a controller, information indicative of a current exhaust temperature;

determining, by a controller, a difference between a current exhaust temperature and a predicted exhaust temperature, the difference indicative of a predicted change in an amount of reductant bound to a Selective Catalytic Reduction (SCR) catalyst of an exhaust aftertreatment system in exhaust receiving communication with an engine;

determining, by the controller, a smoothing command; and

controlling, by the controller, the vehicle system in accordance with the smoothing command to compensate for a difference between the current exhaust temperature and the predicted exhaust temperature to compensate for a predicted change in reductant associated with the SCR catalyst due to the difference.

16. The method of claim 15, wherein the information indicative of upcoming route conditions comprises at least one of road height, road grade, road curvature, road type, speed limit, humidity, temperature, wind speed, time of day, or precipitation.

17. The method of claim 15, wherein the information indicative of the current vehicle operating conditions comprises: the mass of the vehicle, the current engine speed, the current engine load, the current temperature of the exhaust gas produced by the engine, the current NOx concentration at or near the inlet of the SCR catalyst, or the current NOx concentration at or near the outlet of the SCR catalyst.

18. The method of claim 15, wherein the smoothing command comprises changing an engine speed or a gear setting of a transmission coupled to an engine.

19. The method of claim 15, wherein the exhaust aftertreatment system includes one or more reductant dosers configured to provide reductant into the exhaust stream, and the smoothing command is configured to change operation of the one or more reductant dosers.

20. The method of claim 19, further comprising determining, by the controller, a predicted change in an ammonia nitrogen oxide ratio (ANR) of the exhaust based on the difference, and wherein the smoothing command is determined based on the predicted change in ANR.