Vehicle systems and methods for aftertreatment preheating

Vehicle systems and methods are provided for preheating an aftertreatment system prior to engine ignition. A method involves obtaining a first measurement indicative of a current temperature associated with the aftertreatment system, obtaining a second measurement indicative of a current state of an energy source coupled to a heating element integrated with the aftertreatment system, determining an amount of electrical energy to be applied to the heating element based at least in part on a difference between the current temperature associated with the aftertreatment system and a target temperature for the aftertreatment system, and automatically enabling current flow from the energy source to the heating element prior to ignition of the engine for a duration of time in a manner that is influenced by the amount of electrical energy to be applied to the heating element and the current state of the energy source.

INTRODUCTION

The technical field generally relates to vehicle systems and more particularly relates to preheating a catalytic converter or other aftertreatment system for automotive applications.

Many vehicles rely on combustion engines for propulsion. Combustion results in exhaust gases emitted from the engine that include, but are not limited to, carbon monoxide, carbon dioxide, unburned hydrocarbons, oxides of nitrogen (NOx), and oxides of sulfur (SOx), as well as condensed phase materials (liquids and solids) that constitute particulate matter. Exhaust gas treatment systems typically employ catalysts in a catalytic converter, emissions control device or component of an aftertreatment system in order to reduce exhaust gas emissions. Exhaust gas interacting with the catalyst converts exhaust constituents into more tolerable exhaust constituents, such as, for example, nitrogen and water. However, catalysts employed for emissions controls typically exhibit suboptimal performance below a so-called “light off” temperature, above which the catalyst is more catalytically active or efficient. Since a disproportionate amount of emissions are attributable to engine operation at startup, alternatively referred to as cold start emissions, it is desirable to achieve catalyst light off temperature prior to ignition.

SUMMARY

Vehicle systems and methods are provided for preheating an aftertreatment system downstream of an engine of a vehicle prior to ignition of the engine. One method involves a control module associated with a vehicle obtaining a first measurement indicative of a current temperature associated with the aftertreatment system, obtaining a second measurement indicative of a current state of an energy source coupled to a heating element integrated with the aftertreatment system, determining an amount of electrical energy to be applied to the heating element based at least in part on a difference between the current temperature associated with the aftertreatment system and a target temperature for the aftertreatment system, and automatically enabling current flow from the energy source to the heating element prior to ignition of the engine for a duration of time in a manner that is influenced by the amount of electrical energy to be applied to the heating element and the current state of the energy source.

In one aspect, automatically enabling the current flow involves the control module automatically operating a switching arrangement coupled between the energy source and the heating element for the duration of time with a duty cycle, where the control module determines the duty cycle based at least in part on the current state of the energy source and the difference between the current temperature associated with the aftertreatment system and the target temperature for the aftertreatment system. In one implementation, determining the duty cycle involves the control module determining the duty cycle to minimize the duration of time for applying the amount of electrical energy based on the current state of the energy source. In another implementation, determining the duty cycle involves the control module determining the duty cycle based at least in part on an overheating threshold temperature associated with the heating element.

In another aspect, the method involves automatically enabling an auxiliary air injection device to provide fluid flow past the heating element through the aftertreatment system after enabling the current flow from the energy source to the heating element. In one implementation, the control module determines a temperature associated with the heating element is greater than a threshold prior to automatically enabling the auxiliary air injection device. In another implementation, the control module determines a duty cycle for operating the auxiliary air injection device based at least in part on the current temperature associated with the aftertreatment system, wherein automatically enabling the auxiliary air injection device involves operating the auxiliary air injection device with the duty cycle.

In one implementation, the method involves the control module detecting a potential startup condition for the engine, identifying the duration of time based on a type of the potential startup condition, and determining a duty cycle for the current flow from the energy source to the heating element to achieve the amount of electrical energy based at least in part on the duration of time and the current state of the energy source, wherein automatically enabling the current flow involves automatically operating a switching arrangement coupled between the energy source and the heating element with the duty cycle for the duration of time. In another implementation, the heating element is a resistive element contained within a housing of an emissions control device of the aftertreatment system. In some implementations, the resistive element is disposed upstream of a catalyst component within the housing of the emissions control device and the target temperature is a targeted light off temperature associated with the catalyst component. In one aspect, obtaining the first measurement involves obtaining the first measurement from a temperature sensing element within the housing of the emissions control device, wherein the temperature sensing element is upstream of at least one of the resistive element and the catalyst component.

A vehicle system is provided that includes an energy source, an emissions control device including a heating element coupled to the energy source and at least one catalyst component, a temperature sensing element to obtain a first measurement indicative of a current temperature associated with the emissions control device, and a control module coupled to the heating element and the energy source. The control module is configurable to detect a potential startup condition for an engine upstream of the emissions control device, obtain a second measurement indicative of a current state of the energy source, determine an amount of electrical energy to be applied to the heating element based at least in part on a difference between the current temperature and a target temperature for the at least one catalyst component, and automatically enable current flow from the energy source to the heating element for a duration of time in a manner that is influenced by the amount of electrical energy to be applied to the heating element and the current state of the energy source. In one aspect, the control module is configurable to determine a duty cycle for operating the heating element based at least in part on the current state of the energy source and automatically enable the current flow by operating a switching arrangement between the energy source and the heating element in accordance with the duty cycle determined based at least in part on the current state of the energy source. In another aspect, the control module is configurable to determine the duty cycle to minimize the duration of time for achieving the amount of electrical energy applied to the heating element based at least in part on a current voltage of the energy source. In one implementation, the control module is configurable to maximize the duty cycle based at least in part on an overheating threshold temperature associated with the heating element.

In another implementation, the vehicle system includes an auxiliary air injection device upstream of the emissions control device to provide a fluid flow through the emissions control device, wherein the control module is coupled to the auxiliary air injection device and configurable to automatically enable the auxiliary air injection device to provide the fluid flow after enabling the current flow from the energy source to the heating element. In one implementation, the control module is configurable to verify a temperature associated with the heating element is greater than a threshold prior to automatically enabling the auxiliary air injection device. In another implementation, the control module is configurable to determine a duty cycle for operating the auxiliary air injection device based at least in part on the current temperature and operate the auxiliary air injection device with the duty cycle.

An apparatus for a non-transitory computer-readable medium is also provided. The non-transitory computer-readable medium has executable instructions encoded or stored thereon that, when executed by a processor, cause the processor to provide an aftertreatment system preheating service configurable to obtain a first measurement indicative of a current temperature associated with an aftertreatment system downstream an engine of a vehicle, obtain a second measurement indicative of a current state of an energy source coupled to a heating element integrated with the aftertreatment system, determine an amount of electrical energy to be applied to the heating element based at least in part on a difference between the current temperature associated with the aftertreatment system and a target temperature for the aftertreatment system, and automatically enable current flow from the energy source to the heating element for a duration of time prior to ignition of the engine in a manner that is influenced by the amount of electrical energy to be applied to the heating element and the current state of the energy source. In one implementation, the aftertreatment system preheating service is configurable to verify a temperature associated with the heating element is greater than a threshold after enabling the current flow, and after verifying the temperature associated with the heating element is greater than the threshold, determine a duty cycle for operating an auxiliary air injection device based at least in part on the current temperature associated with the aftertreatment system and automatically operate the auxiliary air injection device with the duty cycle.

DETAILED DESCRIPTION

FIG.1depicts a layout of an exemplary vehicle system100having an exhaust gas aftertreatment system102that includes a pair of emissions control devices104,106downstream of an engine108. In this regard,FIG.1depicts an implementation of an engine108having a V-type cylinder arrangement (e.g., a V8 internal combustion engine (ICE)) having separate exhaust manifolds110,112, where each exhaust manifold110,112is in fluid communication with a respective one of the emissions control devices104,106via a respective duct or conduit114,116for directing exhaust gas flow exiting the respective manifold110,112to the inlet or intake of a respective emissions control device104,106. It should be appreciated that the subject matter described herein is not limited to any particular type or configuration of engine or any particular type or configuration of vehicle; however, for purposes of explanation, the subject matter will be described in the context of an internal combustion engine (ICE) used for propulsion of an automotive vehicle, such as, for example, a V8 engine suitable for use in a passenger car, sedan, van, truck, sport utility vehicle (SUV), recreational vehicle (RV) or the like.

In exemplary implementations, the emissions control devices104,106are realized as duplicate instances of a catalytic converter including an electrically heated catalyst. In the illustrated implementation inFIG.1, the emissions control devices104,106include respective instances of a heating element120integrated with or otherwise contained within the housing of the respective emissions control devices104,106upstream of respective instances of catalyst components (or catalysts)122,124. Each catalyst component122,124may include or otherwise be realized as a substrate having a chemical compound, composition or other coating applied to the substrate that is configured to chemically react with compounds or constituents within the exhaust gas flow to convert those compounds or exhaust gas constituents into other substances, thereby detoxifying the exhaust gas flow prior to emission. Depending on the implementation, the respective catalyst components122,124may be identical to one another or different from one another. For example, in some implementations, the first stage catalyst components122may be realized as 3-way catalysts while the second stage catalyst components124are realized as 4-way catalysts, or vice versa. As described in greater detail below, the heating elements120are operated prior to ignition or starting of the engine108to proactively increase the temperature of the catalyst components122,124in anticipation of a startup event, and thereby improve the performance and efficiency of the emissions control devices104,106with respect to so-called cold start emissions.

In exemplary implementations, the aftertreatment system102also includes respective instances of an auxiliary air injection device126that is upstream of the emissions control devices104,106via an auxiliary duct or conduit between the outlet of a respective auxiliary air injection device126and the inlet or intake of the respective emissions control device104,106. In this regard, exemplary implementations include a respective valve128disposed within an auxiliary conduit between the respective auxiliary air injection device126and the inlet of the respective emissions control device104,106to selectively enable or disable fluid flow between the auxiliary air injection device126and the emissions control device104,106. In exemplary implementations, the auxiliary air injection device126is realized as an air compressor or similar air pump that is operable to compress and direct ambient air into the respective emissions control device104,106via the auxiliary conduit and valve128. As described in greater detail below, the auxiliary air injection devices126are operated after activation of the heating elements120but prior to ignition or starting of the engine108to provide fluid flow through the emissions control devices104,106that heat the catalyst components122,124by virtue of the upstream heating element120heating the fluid flow before reaching the catalyst components122,124. In this regard, the operation of the heating elements120and the auxiliary air injection devices126may be cooperatively configured to minimize the duration of time required to heat the catalyst components122,124to temperatures that are greater than or equal to the threshold light off temperature for achieving a desired level of efficiency of the catalyst components122,124.

Still referring toFIG.1, in exemplary implementations, the emissions control devices104,106include temperature sensing elements130(or temperature sensors) that are integrated with, disposed within or otherwise contained within the housing of the respective emissions control devices104,106to obtain temperature measurement values indicative of the current temperature associated with the aftertreatment system102, that is, the temperature of the gas flow within the respective emissions control devices104,106. Additionally, the vehicle system100may include temperature sensing elements (or temperature sensors) configured to obtain temperature measurement values indicative of the current temperature associated with the exhaust gas flow. In this regard, depending on the implementation, the temperature sensing elements may be integrated with, disposed within or otherwise contained within the exhaust manifolds110,112and/or the exhaust conduits114,116to obtain a measurement of the exhaust gas flow upstream of the emissions control devices104,106.

Although not illustrated inFIG.1, as described in greater detail below, in exemplary implementations, a control module or other computing device is coupled to the heating elements120, the auxiliary air injection devices126, the valves128and the temperature sensing elements130and is configurable to operate the heating elements120, the auxiliary air injection devices126and the valves128in a manner that is influenced by the temperature measurements obtained via the temperature sensing elements130to efficiently preheat the emissions control devices104,106prior to startup of the engine108. In this regard, the control module or computing device that operates the heating elements120, the auxiliary air injection devices126and the valves128may be implemented or realized using any sort of electronic component onboard the vehicle that includes at least one processor and data storage element, including, but not limited to, a system on a chip, integrated circuit or another electronics module. The processor can include or be realized as any custom made or commercially available processor, a central processing unit (CPU), a graphics processing unit (GPU), an auxiliary processor among several processors associated with the control module, a semiconductor-based microprocessor (in the form of a microchip or chip set), a macroprocessor, any combination thereof, or generally any device for executing instructions. The data storage element includes or is otherwise realized as a non-transitory computer readable storage device or media, which may include volatile and nonvolatile storage in read-only memory (ROM), random-access memory (RAM), and keep-alive memory (KAM). For example, the data storage element may be implemented using any of a number of known memory devices such as PROMs (programmable read-only memory), EPROMs (electrically PROM), EEPROMs (electrically erasable PROM), flash memory, or any other electric, magnetic, optical, or combination memory devices capable of storing data, some of which represent executable instructions, used by the processor. The instructions may include one or more separate programs, each of which comprises an ordered listing of executable instructions for implementing logical functions. The instructions, when executed by the processor, cause the processor to support or otherwise provide an aftertreatment system preheating service and perform logic, calculations, methods and/or algorithms for supporting the subject matter described herein.

FIG.2depicts an exemplary implementation of a control system200suitable for use with the vehicle system100ofFIG.1to support preheating of the aftertreatment system102. The control system200includes a control module202that includes, incorporates or is otherwise coupled to a switching arrangement204that is operable to enable electrical current flow to a heating element206integrated with an emissions control device (e.g., heating element120) from an energy source208associated with the vehicle. In this regard, the energy source208generally represents a battery (or battery pack) onboard the vehicle that supplies power to a so-called low voltage electrical grid onboard the vehicle, such as, for example, a 12 Volt battery, an 18 Volt battery, and/or the like. However, it should be appreciated the subject matter is not limited to any particular type of energy source208and may be implemented in an equivalent manner in the context of any type of energy source, including, but not limited to, a high voltage battery, an ultracapacitor, a fuel cell or the output of a rectifier, DC-to-DC converter or any other power converter. That said, for purposes of explanation, the subject matter will be described herein in the context of the energy source208being realized as a low voltage battery.

In exemplary implementations, the heating element206includes or is otherwise realized using one or more resistors or similar resistive elements capable of dissipating electrical current or power from the energy source208, and thereby, generating heat that elevates the temperature of the heating element206. That said, the heating element206is not limited to any particular type of electrical components, circuitry or configurations, and may vary depending on the implementation.

The switching arrangement204generally represents one or more transistors or other switching elements coupled or otherwise arranged electrically in series between the energy source208and the heating element206to enable or disable current flow between the energy source208and the heating element206, and thereby control activation of the heating element206. It should be noted that althoughFIG.2depicts the switching arrangement204as separate from the control module202, in practice, the switching arrangement204may be integrated or otherwise combined with the control module202.

As described above, the control module202can be implemented or realized using any sort of electronic component onboard the vehicle that includes at least one processor and data storage element, where the data storage element stores or otherwise maintains executable instructions that, when executed by the processor, cause the processor to support or otherwise provide an aftertreatment system preheating service and support the subject matter described herein. As illustrated inFIG.2, the control module202is communicatively coupled to one or more temperature sensing elements210(or temperature sensors) that are configured to provide temperature measurement values indicative of the current temperature associated with the emissions control devices of the aftertreatment system (e.g., temperature sensors130). Additionally, the control module202is coupled to other sensing elements212to provide measurement values indicative of other characteristics or conditions associated with the vehicle system, such as, for example, temperature sensors to provide measurements indicative of the exhaust gas temperature, temperature sensors to provide measurements indicative of the ambient air temperature external to the vehicle, and/or the like along with voltage sensors, current sensors, state of charge (SoC) sensors, or other sensing elements configured to provide measurement values indicative of the current state or condition of the energy source208. The control module202is coupled to an auxiliary air injection device214(e.g., auxiliary air injection device126) and controls operation of the heating element206(via switching arrangement204) and the auxiliary air injection device214to efficiently preheat emission control devices of an aftertreatment system (e.g., emissions control devices104,106of the aftertreatment system102) based on measurement values from the sensors210,212indicative of the current state of the aftertreatment system and/or the vehicle system, as described in greater detail below.

FIG.3depicts an exemplary implementation of an aftertreatment preheating process300that may be implemented or otherwise performed by an aftertreatment system preheating service at a control module of a vehicle system to efficiently preheat the catalyst or other components associated with emissions control devices prior to ignition of an internal combustion engine and perform additional tasks, functions, and/or operations described herein. For illustrative purposes, the following description may refer to elements mentioned above in connection withFIGS.1-2. While portions of the aftertreatment preheating process300may be performed by different elements of a vehicle system, for purposes of explanation, the subject matter may be primarily described herein in the context of the aftertreatment preheating process300being primarily performed by an aftertreatment system preheating service at a vehicle control module202that is coupled to the sensing elements130,210,212and controls operation of the heating elements120,206, the auxiliary air injection devices126,214and/or the valves128.

Referring toFIG.3with continued reference toFIGS.1-2, the aftertreatment preheating process300is initiated or otherwise performed in response to detecting a potential startup condition that is indicative of anticipated ignition of the internal combustion engine. For example, as described in U.S. Pat. No. 10,167,795, the potential startup condition could include a vehicle door opening event (e.g., a user opening one of the vehicle trunk, vehicle driver door, vehicle passenger door, etc.), a seat sensor event (e.g., detection of a user occupying the driver seat), a seat belt sensor event (e.g., detection of a driver seat belt, passenger seat belt or the like being engaged), a fob proximity detection event (e.g., when a key fob, a cellular telephone, or other device capable of communicating proximity to the vehicle is within a threshold range of the vehicle), a remote command (e.g., remote start) or the like.

After detecting the potential startup condition, the aftertreatment preheating process300verifies or otherwise confirms one or more enablement criteria are satisfied before attempting to preheat the aftertreatment system at302. For example, the control module202may analyze measurement values from one or more sensing elements212indicative of the current state or current condition of the energy source208to verify the current state of charge associated with the energy source208is greater than an enable threshold state of charge. In this manner, when the current state of charge is less than the enable threshold, the aftertreatment preheating process300exits or terminates to avoid depletion of the energy source208to ensure adequate state of charge remains to support other functionality (e.g., starting the engine108).

In some implementations, the control module202also tracks or otherwise monitors a number of preheating cycles that have been performed between successive operations of the engine108. In this regard, each time the control module202operates the heating element120,206to preheat the aftertreatment system102, the control module202may increment the value of a counter that is reset when the engine108is started. When the value of the counter is greater than a threshold number of preheating cycles, the aftertreatment preheating process300similarly exits or terminates to avoid depletion of the energy source208or potentially unnecessary operation of the heating elements120,206and the air injection device126,214, for example, when a user keeps approaching the vehicle or entering and exiting the vehicle without starting the engine108.

Additionally, in some implementations, the control module202also tracks or otherwise monitors a duration of time that has elapsed since the engine108was most recently operated to ensure the engine off time is greater than a threshold duration of time within which it is unlikely that both the temperature of the catalyst components122,124will fall below the light off temperature or a threshold temperature required to achieve a desired level of performance and that the user will want to restart the engine108within that period of time. The control module202may also verify or otherwise confirm that the temperature associated with the emissions control devices104,106is below the light off temperature or another threshold catalyst temperature required to achieve a desired performance of the catalyst components122,124. In other words, various implementations of the aftertreatment preheating process300may only attempt to preheat the aftertreatment system102when the state of charge of the energy source208is greater than a threshold, the number of successive preheating cycles is less than a threshold, the engine time off is greater than a threshold, and the current temperature associated with the aftertreatment system102is less than the light off temperature or other temperature threshold.

When the enablement criteria for a preheating cycle are satisfied, the aftertreatment preheating process300calculates or otherwise determines an amount of electrical energy to be applied to the heating element to raise the catalyst temperature based on current measurement values at304and then automatically operates a switching arrangement to activate or otherwise operate the heating element in accordance with the determined amount of electrical energy at306. In this regard, based on the difference between the current temperature measurement values indicative of the current temperature of the catalyst components122,124obtained from the temperature sensing elements130,210and the targeted light off temperature for the catalyst components122,124, the control module202may calculate or otherwise determine an amount of electrical power to be applied to the heating element120,206and a corresponding duration of time for which to apply the electrical power to raise the temperature of the catalyst components122,124from the current temperature to the targeted light off temperature at the end of that duration of time. The control module202then automatically operates or otherwise activates the switching arrangement204to thereby operate or activate the heating elements120,206to cause the heating elements120,206to dissipate or otherwise consume the determined amount of electrical energy over the determined duration of time.

In some implementations, the duration of time is identified or determined based on the type of potential startup condition that was detected, such that different potential startup conditions may utilize different amounts of electrical power to achieve the targeted light off temperature prior to starting the engine108. For example, detecting an occupant in the driver seat of the vehicle may entail a shorter preheating cycle duration (e.g., because starting the engine108is more imminent) than a key fob detection event or a remote start command event where more immediate starting of the engine108is less likely. Based upon the anticipated available duration of time for preheating, the control module202may calculate or otherwise determine an amount of electrical power to be applied to the heating element120,206within that anticipated available duration of time based on the difference between the current temperature associated with the aftertreatment system102and the targeted light off temperature. In this regard, for longer duration preheating cycles, higher initial aftertreatment system temperatures and/or lower targeted light off temperatures, the control module202may determine a reduced amount of power is required, while shorter duration preheating cycles, lower initial aftertreatment system temperatures and/or higher targeted light off temperatures may result in an increased amount of power being required.

In exemplary implementations, based on the amount of power required, the control module202determines a corresponding duty cycle at which to operate the switching arrangement204or may otherwise operate the energy source208and/or the heating elements120,206to achieve the desired power consumption over the anticipated available duration of time, resulting in cumulative consumption of the determined amount of electrical energy required to raise the temperature of the catalyst components122,124from the current temperature to the targeted light off temperature. In this manner, the duration of the preheating cycle may be optimized and/or minimized depending on the particular startup condition to increase the likelihood of the preheating cycle completing prior to ignition of the engine108, with the power consumption being similarly optimized and/or minimized to conserve availability of the energy source208and/or reduce wear or stress on the heating elements120,206and/or the switching arrangement204.

Still referring toFIG.3, the aftertreatment preheating process300determines whether to operate an auxiliary air injection device at308. In response to determining the auxiliary air injection device should be operated, the aftertreatment preheating process300calculates or otherwise determines commands for operating the auxiliary air injection device to raise the catalyst temperature to the targeted light off temperature within the determined duration for the preheating cycle at310and then automatically operates or otherwise activates the auxiliary air injection device in accordance with the determined commands at312. In this regard, depending on the potential startup condition, the current temperature of the emissions control devices104,106and/or potentially other factors, the control module202may determine that the auxiliary air injection devices126,214should be operated to generate fluid flow through the emissions control devices104,106to convectively heat the catalyst components122,124within the emissions control devices104,106that are downstream of the heating element120,206. For example, when the duty cycle associated with the operation of the switching arrangement204and/or the heating elements120,206is greater than a threshold (e.g., a duty cycle greater than 90%), the control module202may determine that the auxiliary air injection devices126,214should be operated to prevent overheating of the heating elements120,206and/or to increase heat transfer to the downstream catalyst components122,124to increase the likelihood of reaching the targeted light off temperature prior to ignition. In this regard, when the duration of the preheating cycle is relatively short, the auxiliary air injection devices126,214may be operated to increase the rate at which the downstream catalyst components122,124are heated, and thereby, increase the likelihood of the downstream catalyst components122,124achieving the targeted light off temperature (e.g., if the engine108is prematurely started before completion of the preheating cycle).

Similar to the heating elements120,206and the switching arrangement204, in exemplary implementations, the control module202calculates or otherwise determines a duty cycle for using pulse-width modulated (PWM) commands to operate the auxiliary air injection devices126,214based at least in part on the current temperature associated with the emissions control devices104,106and may vary the duty cycle for operating the auxiliary air injection devices126,214, and thereby vary the rate of fluid flow past the heating elements120,206during the preheating cycle. For example, when the measured temperature of the emissions control devices104,106obtained via the integrated sensing elements130,210is relatively lower, the control module202may operate the auxiliary air injection devices126,214with a lower duty cycle (e.g., to limit heat transfer and allow the temperature of the heating element120,206to increase) than when the measured temperature of the emissions control devices104,106is greater, at which point the control module202may operate the auxiliary air injection devices126,214with an increased duty cycle to increase fluid flow, and thereby, increase convective heat transfer from the heating element120,206to the downstream catalyst components122,124.

Still referring toFIG.3, the aftertreatment preheating process300continues by operating the heating element and/or auxiliary air injection device until detecting or otherwise identifying a termination condition at314and then deactivating the preheating components at316. In this regard, depending on the current measurements or other data or information obtained via the various sensing elements130,210,212, the control module202may maintain operation of the heating element120,206and the auxiliary air injection device214for the duration of the preheating cycle and/or until one or more termination criteria are satisfied prior to the preheating cycle elapsing. For example, in response to detecting a current temperature associated with the aftertreatment system102and/or the exhaust gas flow that is greater than the targeted light off temperature, the control module202may terminate operation of the heating element120,206and the auxiliary air injection device214. In some implementations, the control module202may terminate operation of the heating element120,206and the auxiliary air injection device214in response to detection ignition of the engine108. That said, in other implementations, the control module202may maintain operation of at least one of the heating element120,206and the auxiliary air injection device214after ignition of the engine108until the termination criteria are satisfied. For example, when the current temperature of the exhaust gas obtained via sensing elements is greater than the ambient air temperature, the control module202may terminate operation of the auxiliary air injection device126,214and close the valves128once the exhaust gas becomes more effective at heating the catalyst components122,124.

FIG.4depicts an exemplary implementation of an electrical preheating process400that may be implemented or otherwise performed in connection with the aftertreatment preheating process300(e.g., at304) to determine how to operate an electrical heating element for preheating catalysts or other components associated with emissions control devices and perform additional tasks, functions, and/or operations described herein. For illustrative purposes, the following description may refer to elements mentioned above in connection withFIGS.1-2. For purposes of explanation, the subject matter may be primarily described herein in the context of the electrical preheating process400being primarily performed by the aftertreatment system preheating service at the vehicle control module202.

The electrical preheating process400initializes or begins after detecting a potential startup condition and verifying enablement criteria have been satisfied for preheating the aftertreatment system (e.g., at302). The electrical preheating process400identifies or otherwise obtains one or more measurement values indicative of the current temperature associated with the aftertreatment system at402and corresponding target temperature values for the aftertreatment system at404. In this manner, the difference between the current temperature of the emissions control devices104,106obtained via the sensing elements130,210and the targeted light off temperature for the catalyst components122,124influences the duration and manner in which the electrical heating element120,206is operated. For example, the aftertreatment system preheating service at the vehicle control module202may utilize the difference in temperature between the measured current temperature associated with the emissions control devices104,106and the targeted light off temperature to calculate or otherwise determine an amount of thermal energy transfer required to achieve the targeted light off temperature.

The electrical preheating process400also identifies or otherwise obtains one or more measurement values indicative of the current state of the energy source at406. In this regard, the aftertreatment system preheating service at the vehicle control module202may obtain measurements indicative of the current voltage and/or the current state of charge associated with the energy source208via one or more sensing elements212. Based on the current voltage and/or the current state of charge associated with the energy source208, the aftertreatment system preheating service at the vehicle control module202varies one or more of the duty cycle for operating the switching arrangement204and/or the duration of the preheating cycle for which the switching arrangement204is operated to achieve a desired power flow for achieving the desired amount of thermal energy transfer within a particular amount of time. In exemplary implementations, electrical preheating process400also identifies or otherwise obtains information characterizing or quantifying the impedance associated with the electrical heating element at408along with information characterizing or quantifying one or more overheating threshold temperatures associated with the electrical heating element at410. In this regard, the overheating threshold temperatures represent a maximum temperature threshold above which the heating element120,206may be susceptible to damage due to thermal stress.

At412, the electrical preheating process400calculates or otherwise determines commands for operating the electrical heating element with a particular duty cycle for a particular duration of time based at least in part on the difference between the current temperature of the aftertreatment system and the targeted temperature for the aftertreatment system in a manner that is influenced by one or more of the current energy source conditions, the impedance of the heating element and the overheating threshold(s) associated with the heating element. For example, the aftertreatment system preheating service may utilize the impedance of the heating element120,206and the overheating temperature threshold(s) to calculate or otherwise determine a maximum current flow through the heating element120,206that prevents overheating. Based on the maximum current flow and the current voltage of the energy source208, the aftertreatment system preheating service may calculate or otherwise determine a maximum duty cycle for operating the switching arrangement204to achieve a resulting current flow through the heating element120,206that is less than or equal to the maximum current flow. In this manner, the aftertreatment system preheating service determines a duty cycle for operating the switching arrangement204that maximizes heating of the catalyst components122,124while avoiding overheating the heating element120,206. Based on the required amount of thermal energy transfer for reaching the targeted light off temperature, the aftertreatment system preheating service may then calculate or otherwise determine a preheating cycle duration for which the determined duty cycle should be applied until achieving the amount of heat transfer required to reach the targeted light off temperature. In this regard, some implementations of the electrical preheating process400may optimize preheating by maximizing the duty cycle and minimizing the preheating cycle duration given the current energy source conditions without overheating.

In yet other implementations, the aftertreatment system preheating service may identify or otherwise determine the preheating cycle duration based on the type of detected startup condition that triggered the aftertreatment preheating process300, and then optimize the duty cycle or energy transfer rate for that particular preheating cycle duration. For example, certain types of potential startup conditions (e.g., driver seat occupancy or driver seat belt engagement) may be more indicative of an imminent ignition event that requires a shorter preheating cycle, while other potential startup conditions (e.g., proximity detection of a key fob) may have a more relaxed preheating cycle duration. Based on the particular preheating cycle duration assigned to the detected startup condition, the aftertreatment system preheating service may divide the estimated amount of thermal energy transfer required based on the difference between the current temperature of the aftertreatment system and the targeted light off temperature by the assigned preheating cycle duration to arrive at an amount of power consumption for the heating element120,206. Based on the targeted amount of power consumption for the heating element120,206, a corresponding duty cycle for the switching arrangement204may be determined based on the current voltage and/or current state of charge of the energy source208to achieve the desired power flow to the heating element120,206. In such implementations, when the resulting duty cycle is anticipated to result in a temperature of the heating element120,206exceeding an overheating threshold temperature, the aftertreatment system preheating service may automatically operate the auxiliary air injection device126,214to avoid overheating, as described in greater detail below.

As described above in the context ofFIGS.1-3, after performing the electrical preheating process400at304to determine the appropriate duty cycle and duration for operating the electrical heating element120,206, the aftertreatment system preheating service at the control module202automatically operates the switching arrangement204with the determined duty cycle for the determined preheating cycle duration (e.g., at306and314) to achieve the desired rate of heat transfer to the catalyst components122,124to achieve the targeted light off temperature prior to ignition of the engine108. In this manner, the electrical preheating process400optimizes the preheating by either minimizing the preheating cycle duration or otherwise optimizing the duty cycle of the heating element120,206to facilitate achieving the targeted light off temperature within a limited duration of time.

FIG.5depicts an exemplary implementation of an auxiliary preheating process500that may be implemented or otherwise performed in connection with the aftertreatment preheating process300(e.g., at308,310,312and314) to determine whether and how to operate an auxiliary air injection device in connection with an electrical heating element for preheating catalysts or other components associated with emissions control devices and perform additional tasks, functions, and/or operations described herein. For illustrative purposes, the following description may refer to elements mentioned above in connection withFIGS.1-2. For purposes of explanation, the subject matter may be primarily described herein in the context of the auxiliary preheating process500being primarily performed by the aftertreatment system preheating service at the vehicle control module202.

The illustrated auxiliary preheating process500initializes or begins after detecting a potential startup condition and verifying enablement criteria have been satisfied for preheating the aftertreatment system (e.g., at302). The auxiliary preheating process500identifies or otherwise obtains one or more measurements indicative of the current temperature associated with the aftertreatment system at502and determines whether or not to enable the auxiliary air injection device at504based at least in part on the current temperature of the aftertreatment system. In this regard, the aftertreatment system preheating service delays enabling the auxiliary air injection device126,214until the heating element120,206has generated or produced enough heat such that ambient fluid flow past the heating element120,206will adequately transfer heat to the downstream catalyst components122,124. For example, in some implementations, the auxiliary preheating process500may verify the current temperature associated with the emissions control devices104,106obtained via the temperature sensing elements130,210is greater than at least a threshold temperature before enabling the auxiliary air injection device126,214. In some implementations, the aftertreatment system preheating service may utilize the impedance of the heating element120,206and the determined duty cycle for operating the heating element120,206to model or otherwise estimate a duration of time after initiating operation of the heating element120,206that is required for the temperature of the heating element120,206to reach a threshold temperature, and automatically enable operation of the auxiliary air injection device126,214when that amount of time has elapsed. In this manner, the aftertreatment system preheating service attempts to ensure operation of the auxiliary air injection device126,214will effectively heat the downstream catalyst components122,124(e.g., rather than cooling the heating element120,206).

After determining the auxiliary air injection device should be enabled, the auxiliary preheating process500automatically operates one or more valves to enable fluid flow from the auxiliary air injection device to the aftertreatment system at506. The auxiliary preheating process500identifies or otherwise obtains one or more measurements indicative of the current temperature associated with the ambient air to be injected at508and then calculates or otherwise determines a duty cycle for PWM commands to be utilized to operate the auxiliary air injection device based at least in part on the current ambient air temperature and the difference between the current temperature associated with the aftertreatment system and the targeted temperature at510. In this regard, the aftertreatment system preheating service may vary the PWM duty cycle utilized to operate the auxiliary air injection device126,214to pulse or vary the fluid flow through the emissions control devices104,106in a manner that is influenced by the current ambient air temperature and the current temperature of the heating element120,206and/or the aftertreatment system to optimize heat transfer to the catalyst components122,124. For example, at cooler ambient air temperatures, the aftertreatment system preheating service may utilize a lower PWM duty cycle at lower measurements values for the current temperature of the aftertreatment system to reduce the likelihood of the ambient air flow cooling the aftertreatment system, while, conversely, when the ambient air temperatures are higher and/or the current temperature of the aftertreatment system is closer to the overheating threshold for the heating element120,206, the aftertreatment system preheating service may increase the PWM duty cycle to increase the volume of fluid flow to cool the heating element120,206and increase heat transfer to the downstream catalyst components122,124. In this regard, the PWM duty cycle for operating the auxiliary air injection device126,214may be optimized to achieve a desired relationship between cooling the heating element120,206and heating the downstream catalyst components122,124that minimizes preheating cycle or otherwise optimizes heat transfer within the preheating cycle.

After determining PWM commands for operating the auxiliary air injection device, the auxiliary heating process500automatically operates the auxiliary air injection device with the determined PWM duty cycle in accordance with the determined PWM commands at512until detecting or otherwise identifying a termination condition for ceasing operation of the auxiliary air injection device at514. In this regard, depending on the implementation, various different criteria for terminating operation of the auxiliary air injection device126,214independently from the operation of the heating element120,206may be defined. For example, in some implementations, the aftertreatment system preheating service may automatically disable or terminate operation of the auxiliary air injection device126,214in response to a startup event or ignition of the engine108. In other implementations, the aftertreatment system preheating service maintains operation of the auxiliary air injection device126,214after a startup event and monitors the temperature of the exhaust gas until terminating operation of the auxiliary air injection device126,214in response to detecting the measured temperature of the exhaust gas within the conduits114,116exceeds the ambient air temperature. Additionally, in some implementations, the aftertreatment system preheating service may automatically disable or terminate operation of the auxiliary air injection device126,214when the amount of elapsed time since initiating operation of the heating element120,206has reached or exceeded the determined preheating cycle duration for the particular type of potential startup condition that was detected. Prior to a termination condition, the loop defined by504,506,508,510,512and514may repeat during the duration of the preheating cycle to dynamically vary the PWM duty cycle and corresponding commands for operating the auxiliary air injection device126,214based on the current temperature measurements obtained via the temperature sensing elements130,210. In this regard, the PWM duty cycle, and thereby, the rate of fluid flow, may dynamically vary to increase or decrease the amount of fluid flow past the heating elements120,206and through the downstream catalyst components122,124depending on the current thermal condition of the emissions control devices104,106of the aftertreatment system102.

FIG.6depicts another layout of an exemplary vehicle system600having an exhaust gas aftertreatment system602that includes multiple emissions control devices504,506,508downstream of an engine108. In this regard,FIG.6depicts an implementation having dual first stage emissions control devices604,606associated with the respective exhaust conduits114,116from the engine108, where the respective ducts or conduits614,616for directing exhaust gas flow exiting the respective emissions control devices604,606merge at or before the inlet or intake of a second stage emissions control device608downstream of the first stage emissions control devices604,606. Various elements depicted inFIG.6are similar to counterpart elements described above in the context ofFIG.1and will not be redundantly described in the context ofFIG.6.

In the implementation ofFIG.6, the heating element120is integrated with or otherwise contained within the housing of the downstream second stage emissions control device608. In exemplary implementations, the first stage emissions control devices604,606are realized as duplicate instances of a catalytic converter including instances of a first catalyst component122, while the second stage emissions control device608includes a second catalyst component124. In a similar manner as described above, the heating elements120is operated prior to ignition or starting of the engine108to proactively increase the temperature of the catalyst components124of the second stage emissions control device608in anticipation of a startup event, and thereby improve the performance and efficiency of the aftertreatment system602.

In the implementation ofFIG.6, the aftertreatment system102includes a single instance of an auxiliary air injection device126(and associated valve128) that is upstream of the second stage emissions control device608via an auxiliary duct or conduit between the outlet of the auxiliary air injection device126and the inlet or intake of the second stage emissions control device608. As described above, the auxiliary air injection device126may be operated after activation of the heating element120but prior to ignition or starting of the engine108to provide fluid flow through the second stage emissions control device608that heats the catalyst component124by virtue of the upstream heating element120heating the fluid flow before reaching the catalyst component124.

It should be noted that in other implementations, the exhaust conduits114,116may be merged upstream of a single instance of an emissions control device104,106, such that only a single (or individual) instance of an auxiliary air injection device126(and associated valve128) may be present in connection with a single (or individual) instance of the emissions control device104,106. In this regard, the subject matter described herein is not limited to any particular layout or topology for the vehicle system or the aftertreatment system.

While at least one exemplary aspect has been presented in the foregoing detailed description, it should be appreciated that a vast number of variations exist. It should also be appreciated that the exemplary aspect or exemplary aspects are only examples, and are not intended to limit the scope, applicability, or configuration of the disclosure in any way. Rather, the foregoing detailed description will provide those skilled in the art with a convenient road map for implementing the exemplary aspect or exemplary aspects. It should be understood that various changes can be made in the function and arrangement of elements without departing from the scope of the disclosure as set forth in the appended claims and the legal equivalents thereof.