Patent Description:
Pre-heating of aftertreatment systems is becoming increasingly important for optimizing emission performance and fuel economy of combustion engines, such as in vehicles. For example, an exhaust aftertreatment system (EATS) can be electrically heated prior to an engine start in order to enhance nitrogen oxide (NOx) conversion and to reduce cold start emissions. If the EATS is warm when the engine is started, it is possible to run the engine in a fuel economic mode which reduces fuel consumption. If the EATS is cold or not sufficiently warm when the engine is started, the fuel consumption may be high and the engine may produce exhaust gases with an excessive amount of particles and NOx which cannot be removed from the exhaust gases properly. Furthermore, driving with a cold EATS may increase an overall strain on the engine which may reduce the engine lifetime and/or performance. When the EATS is pre-heated for a too long time before vehicle departure, energy and fuel are wasted for keeping the EATS warm during the time the vehicle is not driving. When the EATS is not heated at all, or not heated sufficiently before the vehicle departure, the engine of the vehicle is cold started, thereby producing excess cold start emissions and operating with poor fuel consumption.

Hence, there is an ongoing strive to improve pre-heating of aftertreatment systems, and thereby improving fuel economy and reducing cold start emissions. <CIT> discloses a pre-heating of an aftertreatment system in response to a remote signal.

An object of the invention is to provide an in at least some aspect improved method for reducing waste of fuel and energy, and/or for reducing cold start emissions in exhaust gases produced by combustion engines.

According to a first aspect, the above object is achieved by a method according to claim <NUM>.

Hence, there is provided a method performed by a control unit in connection with a pre-heating process of an aftertreatment system for a combustion engine. The method comprises:.

By defining one or more success criteria and ensuring that they are fulfilled, the aftertreatment system is pre-heated accurately and thus reduces cold start emissions and waste of fuel and energy. The aftertreatment system may now operate in an efficient manner, and as a consequence, a performance increase of the combustion engine may be triggered. This is since when the aftertreatment system is pre-heated, the combustion engine is enabled to operate using the performance increase without producing increased exhaust emissions. In other words, the triggered performance increase may correspond to a performance benefit caused by pre-heating the aftertreatment system. Furthermore, the performance increase may incentivize a user, e.g. a driver, to schedule and complete pre-heating of the aftertreatment system before the actual start time of the combustion engine or the actual vehicle departure time. Additionally, when it is needed to achieve a performance target, the performance increase may be necessary to trigger and hence, to achieve the performance target, the aftertreatment system needs to be pre-heated which thus reduces cold start emissions.

Optionally, the one or more success criteria may be one or more predefined success criteria.

Optionally, the one or more success criteria further comprise.

Optionally, triggering the performance increase may comprise triggering any one or more out of:.

Optionally, the pre-heating statistics comprises any one or more out of:.

Optionally, the pre-heating statistics may further comprise information about a share of pre-heating processes of the aftertreatment system fulfilling the one or more success criteria at the one or more previous starts of the combustion engine. The pre-heating statistics may be able to track to which extent pre-heating of the aftertreatment system has been successfully completed during the one or more previous starts of the combustion engine.

Optionally, the method may further comprise logging whether or not the one or more success criteria are fulfilled.

Optionally, logging whether or not the one or more success criteria are fulfilled may further comprise logging any one or more out of:.

Optionally, obtaining the scheduled start time may comprise receiving the scheduled start time from a wireless device. The wireless device may be a mobile phone.

According to a second aspect, there is provided a control unit configured to perform the method according to the first aspect. The control unit may be an electronic control unit.

According to a third aspect, there is provided a vehicle comprising a control unit according to the second aspect, a combustion engine, and an aftertreatment system.

Optionally, the aftertreatment system is arranged to reduce particles and/or NOx emissions of exhaust gases produced by the combustion engine.

Optionally, the vehicle is any one out of a truck, a car, a bus, and a construction equipment vehicle, such as an excavator, wheel loader, articulated hauler, rigid hauler, asphalt paver, compactor, pipelayer or demolition equipment.

According to a fourth aspect, there is provided a computer program comprising program code means for performing the method of the first aspect, when said program is run on a control unit according to the second aspect.

According to a fifth aspect, there is provided a computer readable medium carrying a computer program comprising program code means for performing the method of the first aspect, when said program is run on a control unit according to the second aspect.

is a schematic overview of a vehicle <NUM> in accordance with embodiments herein. The vehicle <NUM> comprises a combustion engine <NUM> for driving the vehicle <NUM>. The vehicle <NUM> comprises an exhaust aftertreatment system <NUM> for reducing harmful exhaust emissions of the combustion engine <NUM>, e.g. reducing particles and NOx of exhaust gases produced by the combustion engine <NUM> and e.g. released as cleaned exhaust gases through an exhaust pipe (not shown). The aftertreatment system <NUM> may also be referred to as an EATS. In other words, the aftertreatment system <NUM> may be a device that cleans exhaust gases produced by the combustion engine <NUM> to ensure that harmful emissions are minimized or at least reduced. The aftertreatment system <NUM> may reduce harmful exhaust emissions by any suitable mechanism, e.g. by converting Carbon Monoxide (CO), hydrocarbons (HC), NOx and other potentially harmful chemicals, this may e.g. involve converting NOx using a reductant, such as urea, in a Selective Catalytic Reduction (SCR) unit. The aftertreatment system <NUM> may additionally or alternatively further clean exhaust gases by removing soot in a particulate filter unit, such as a Diesel Particulate Filter (DPF) unit and/or by converting CO/HC in an oxidation catalyst unit, such as a Diesel Oxidation Catalyst (DOC) unit. When the aftertreatment system <NUM> is warm, a more efficient handling of emissions produced by the combustion engine <NUM> is achieved. A warm aftertreatment system <NUM> may additionally enable the combustion engine <NUM> to operate in a more fuelefficient manner and may also reduce degradation of components of the vehicle <NUM>. When the aftertreatment system <NUM> is too cold, e.g. lower than a threshold temperature, the aftertreatment system <NUM> may not clean exhaust gases at all or at best at a minimum efficiency. This is due to that the cleaning of exhaust gases by the aftertreatment system <NUM> is highly dependent on the temperature of the aftertreatment system <NUM>. For example, when the temperature of the aftertreatment system <NUM> is below <NUM> degrees Celsius (C), the NOx conversion within the SCR unit is typically non-existing. When the temperature of the aftertreatment system <NUM> is <NUM>, about <NUM>% of NOx in the exhaust gases may be converted. For most efficient conversion of exhaust gases, the aftertreatment system <NUM> needs to be heated to above <NUM>° C. For example, when the aftertreatment system <NUM> is heated to a temperature between <NUM> and <NUM>, <NUM>-<NUM>%, or sometimes up to <NUM>% of all NOx may be converted in the exhaust gases produced by the combustion engine <NUM>.

To ensure that the aftertreatment system <NUM> is sufficiently warm, e.g. between <NUM>-<NUM>, in time before starting the combustion engine <NUM>, the aftertreatment system <NUM> may be pre-heated using a pre-heating unit <NUM>. The pre-heating unit <NUM> may heat the aftertreatment system <NUM> using any suitable mechanism using any suitable energy source. For example, the pre-heating unit <NUM> may be arranged to pre-heat the aftertreatment system <NUM> using e.g. electrical energy from a battery in the vehicle <NUM>. The battery may be arranged to be charged using braking energy, e.g. generated by braking one or more wheels <NUM> and/or by engine braking. In this way, the energy of pre-heating the aftertreatment system <NUM> would be emission neutral. The energy could also come from an electrical grid, e.g. by the vehicle <NUM> being connected to an electricity outlet. The energy for charging the battery may also be provided from the combustion engine <NUM>. The vehicle <NUM> is in the scenario of <FIG> illustrated as a truck, but the vehicle <NUM> may also be any other suitable vehicle such as a car, a bus, a construction equipment vehicle, such as an excavator, wheel loader, articulated hauler, rigid hauler, asphalt paver, compactor, pipelayer or demolition equipment, or any other suitable vehicle comprising a combustion engine and an aftertreatment system, such as the combustion engine <NUM> and the aftertreatment system <NUM>.

Embodiments herein may be performed by a control unit <NUM>. The control unit <NUM> may be comprised in the vehicle <NUM> but may also be comprised in any other suitable location. The control unit <NUM> may be communicatively connected with any one or more out of the aftertreatment system <NUM>, the combustion engine <NUM>, and the pre-heating unit <NUM>. The control unit <NUM> may for example be arranged to schedule and/or perform pre-heating of the aftertreatment system <NUM>. The control unit <NUM> may further be arranged to trigger a performance increase of the combustion engine <NUM> when a pre-heating process of the aftertreatment system <NUM> fulfils one or more success criteria. The control unit <NUM> may further be able to obtain and/or log any suitable parameter or statistics related to the operation of the vehicle <NUM> and/or relating to a pre-heating process of the aftertreatment system <NUM>.

The control unit <NUM> may be arranged to receive input from a user <NUM>, e.g. a driver, e.g. via a user interface and/or via a wireless device <NUM> e.g. operated by the user <NUM>. The wireless device <NUM> may be any suitable wireless device that can communicate with the control unit <NUM> using any suitable means. The wireless device <NUM> may e.g. be any one out of a mobile phone, a user equipment (UE), a computer, a laptop, another vehicle, or any other suitable device with networking or other remote communication capabilities. The input may be any suitable input, e.g. relating to a scheduled start time of the combustion engine <NUM> or a scheduled departure time of the vehicle <NUM>.

A storage medium <NUM>, e.g. a database, may be arranged in connection with the control unit <NUM>, e.g. for logging any one out of: pre-heating statistics, time schedules for pre-heating the aftertreatment system <NUM>, and any other suitable parameters related to a pre-heating process of the aftertreatment system <NUM>. The storage medium <NUM> may be comprised in the vehicle <NUM>, e.g. directly connected with the control unit <NUM>, or arranged at a remote location, e.g. in a cloud environment.

<FIG> illustrates example embodiments of a method performed by the control unit <NUM> in connection with a pre-heating process of the aftertreatment system <NUM> for the combustion engine <NUM>. The method described in relation to <FIG>. may in some embodiments be a part of the pre-heating process of the aftertreatment system <NUM>. The method comprises the following actions described below, which actions may be taken in any suitable order. Optional actions are indicated by dashed boxes in <FIG>.

Action <NUM>. The method may start by obtaining a scheduled start time of the combustion engine <NUM>. The start time of the combustion engine <NUM> may correspond to a scheduled departure time of the vehicle <NUM> or be determined from the scheduled departure time. For example, if the scheduled departure time is known, the scheduled start time may be obtained by assuming that the scheduled start time coincides with the scheduled departure time, or that it occurs at a predetermined time before the scheduled departure time. The scheduled start time may be inputted by the user <NUM>. In some embodiments, the user <NUM> inputs the scheduled start time in a user interface of the control unit <NUM>, e.g. arranged in the vehicle <NUM>. In some embodiments, obtaining the scheduled start time comprises receiving the scheduled start time from the wireless device <NUM>, e.g. wherein the scheduled start time is inputted on the wireless device <NUM> by the user <NUM>. The scheduled start time may be for a specific time or may comprise a series of times, e.g. a schedule comprising recurring times such as a fixed time every weekday. For example, the user <NUM> may proactively enter information about when in time the user <NUM> is to depart with the vehicle <NUM>, i.e. the above-mentioned scheduled start time.

Action <NUM>. The method proceeds by scheduling a pre-heating of the aftertreatment system <NUM> to be completed before the scheduled start time. The pre-heating of the aftertreatment system <NUM> may thus be initiated at a suitable time before the scheduled start time. The pre-heating may be scheduled to pre-heat the aftertreatment system <NUM> to a temperature above <NUM>, e.g. to a temperature of <NUM>-<NUM>.

Action <NUM>. The method further comprises detecting a start of the combustion engine <NUM> at an actual start time. The actual start time may be a departure time of the vehicle <NUM>. In this way it is possible to determine how accurate the pre-heating of the aftertreatment system <NUM> performed.

Action <NUM>. The method comprises, in response to the detected start of the combustion engine <NUM>, and using the actual and scheduled start time, determining whether the scheduled pre-heating of the aftertreatment system <NUM> fulfils one or more success criteria. The one or more success criteria may be pre-defined and comprise the actual start time is later than or coincides with the scheduled start time. The one or more success criteria may further comprise a temperature of the aftertreatment system <NUM> is above a predetermined threshold temperature at the actual start time, e.g. above <NUM>.

When the actual start time is later than or coincides with the scheduled start time, it may be assumed that the pre-heating of the aftertreatment system <NUM> has been completed before the actual start time.

When the one or more success criteria is/are fulfilled, it may be assumed that the aftertreatment system <NUM> is pre-heated correctly and will reduce cold start emissions when the combustion engine <NUM> starts.

To avoid wasting resources, e.g. fuel and energy, for keeping the aftertreatment system <NUM> warm for an excessive time before departure of the vehicle <NUM>, the one or more success criteria may also be defined so as to be considered fulfilled when the actual start time of the combustion engine <NUM> is within a predefined time range after a pre-heating completion time. The pre-heating completion time may be the time when the pre-heating of the aftertreatment system <NUM> has completed successfully, e.g. when the temperature of the aftertreatment system <NUM> has exceeded the predetermined threshold temperature. The pre-heating completion time may, e.g., coincide with or occur before the scheduled start time. The time range may be set so that the aftertreatment system <NUM> is still warm when the combustion engine <NUM> is started, even if the actual start time is after the pre-heating completion time. The time range may also be set to limit a time for keeping the aftertreatment system <NUM> warm between a completed pre-heating of the aftertreatment system <NUM> and the actual start time.

Action <NUM>. In some embodiments, the method comprises logging, e.g. to the storage medium <NUM>, whether or not the one or more success criteria are fulfilled. In this way, it may be possible to further determine how well pre-heating of the aftertreatment system <NUM> is performing over time. In some embodiments, logging whether or not the one or more success criteria are fulfilled further comprises logging any one or more out of:.

method comprises obtaining pre-heating statistics indicating whether or not the one or more success criteria were fulfilled at one or more previous starts of the combustion engine <NUM>. The pre-heating statistics may e.g. be obtained from the storage medium <NUM>.

In some embodiments, the pre-heating statistics comprise any one or more out of:.

In some embodiments, the pre-heating statistics further comprise information of a share of pre-heating processes of the aftertreatment system <NUM> fulfilling the one or more success criteria at the one or more previous starts of the combustion engine <NUM>.

In other words, the pre-heating statistics may be able to track to which extent pre-heating of the aftertreatment system <NUM> has been successfully completed during the one or more previous starts of the combustion engine <NUM>.

Action <NUM>. The method comprises, when the one or more success criteria are fulfilled, triggering a performance increase of the combustion engine <NUM>. The performance increase may be possible to trigger since the aftertreatment system <NUM> is pre-heated. Due to the pre-heating of the aftertreatment system <NUM>, the combustion engine <NUM> may operate under better conditions which thus makes the combustion engine <NUM> capable of the increased performance without producing excessive exhaust emissions. The triggered performance increase may incentivize the user <NUM> to pre-heat the aftertreatment system <NUM>. For example, the user <NUM> may need to operate the vehicle <NUM> at a target performance. To achieve the target performance, the vehicle <NUM> needs to operate using the performance increase, and thus, the aftertreatment system <NUM> needs to be scheduled for pre-heating, which thus reduces harmful exhaust cold-start emissions when operating the vehicle <NUM>.

In some embodiments, triggering the performance increase comprises triggering any one or more out of:.

Alternatively or additionally, any other suitable performance increases relating to the combustion engine <NUM> and/or the vehicle <NUM> may be triggered.

Triggering the performance increase is based on the obtained pre-heating statistics. In this way, triggering the performance increase may be conditioned on that the one or more success criteria is/are fulfilled often and/or on a regular basis, e.g. by more than a predetermined success threshold. In other words, the performance increase may only be triggered if cold start emissions are minimized. When the aftertreatment system <NUM> is pre-heated and when the pre-heating statistics indicate that the one or more success criteria is/are fulfilled often and/or on a regular basis, it may be assumed that the combustion engine <NUM> is in a good condition and is capable of triggering the increased performance without producing excessive exhaust emissions. This further incentivizes the user <NUM> to keep pre-heating the aftertreatment system <NUM>.

Above actions and embodiments will now be exemplified by embodiments below. Any embodiment or action above or below may when suitable be combined in any suitable manner.

Some embodiments herein relate to giving a performance increase incentive either for available engine power or maximum engine speed, when the user <NUM> has done a good job at proactively and correctly scheduling times for departure, e.g. a scheduled start time as in action <NUM> above. The maximum engine speed may e.g. limit a maximum speed at which the vehicle <NUM> can travel.

In some embodiments, the user <NUM> may want to depart before the scheduled start time. In these embodiments the performance increase may still be triggered, e.g. as in action <NUM> above, if the user <NUM> waits with starting the combustion engine <NUM> until the aftertreatment system <NUM> has had time to heat up sufficiently after the user <NUM> has powered on the vehicle <NUM>. In this way, the aftertreatment system <NUM> is enabled to clean exhaust gases efficiently directly when the combustion engine <NUM> is started.

The enabled performance increase of embodiments herein, e.g. as described above in action <NUM>, may act as an incentive for the user <NUM> to keep planning start times proactively as much as possible and/or to make sure to wait until the aftertreatment system <NUM> is warm before starting the combustion engine <NUM>.

An example scenario of embodiments herein may involve the following steps:.

Embodiments herein may relate to maintaining statistics, e.g. in the storage medium <NUM>, of how often and/or how consistently the planned departure timing data, if any, corresponds to the actual vehicle departure time(s). In some embodiments this may be implemented by any suitable logic implemented in a control unit, e.g. the control unit <NUM>, e.g. using a temperature of the aftertreatment system <NUM> at start of the combustion engine <NUM>, and/or any other suitable input. This may e.g. be part of pre-heating statistics in action <NUM> above. Some embodiments herein may also maintain statistics, e.g. in the storage medium <NUM>, related to whether or not the user <NUM> waits long enough to allow the aftertreatment system <NUM> to pre-heat before departing when powering up the vehicle <NUM> if not having entered predictive departure data. This may e.g. be part of pre-heating statistics in action <NUM> above. In some further embodiments herein, when pre-heating the aftertreatment system <NUM>, any other suitable units comprised in the vehicle <NUM> may also be pre-heated. For example, the combustion engine <NUM> may be pre-heated alongside pre-heating the aftertreatment system <NUM>. In this way further benefits may be realized such as improving the lifetime and/or performance of the combustion engine <NUM>.

To perform the method actions described herein, the control unit <NUM> may be configured to perform the above actions <NUM>-<NUM>. The control unit <NUM> may for example comprise an arrangement depicted in <FIG>. The control unit <NUM> is in connection with a pre-heating process of an aftertreatment system <NUM> for a combustion engine <NUM>. For example, the control unit <NUM> may control the pre-heating process, e.g. using the pre-heating unit <NUM>. The control unit <NUM> may comprise an input and output interface <NUM> configured to communicate with the entities of embodiments herein, such as e.g. any one or more out of the aftertreatment system <NUM>, the combustion engine <NUM>, the pre-heating unit <NUM>, the wireless device <NUM>, the storage medium <NUM>, and any other suitable device or component comprised in the vehicle <NUM>.

The input and output interface <NUM> may comprise a wireless and/or wired receiver (not shown) and a wireless and/or wired transmitter (not shown), e.g. for communication with and/or control of any of the above named entities.

The control unit <NUM> may be configured to, e.g. by means of an obtaining unit <NUM> in the control unit <NUM>, obtain a scheduled start time of the combustion engine <NUM>.

The control unit <NUM> may be configured to, e.g. by means of the obtaining unit <NUM> in the control unit <NUM>, obtain pre-heating statistics indicating whether or not the one or more success criteria was fulfilled at one or more previous starts of the combustion engine <NUM>.

The control unit <NUM> may be configured to, e.g. by means of a scheduling unit <NUM> in the control unit <NUM>, schedule a pre-heating of the aftertreatment system <NUM> to be completed before the scheduled start time.

The control unit <NUM> may be configured to, e.g. by means of a detecting unit <NUM> in the control unit <NUM>, detect a start of the combustion engine <NUM> at an actual start time.

The control unit <NUM> may be configured to, e.g. by means of a determining unit <NUM> in the control unit <NUM>, in response to the detected start of the combustion engine <NUM>, and using the actual and scheduled start time, determine whether the scheduled pre-heating of the aftertreatment system <NUM> fulfils one or more success criteria.

The control unit <NUM> may be configured to, e.g. by means of a logging unit <NUM> in the control unit <NUM>, log whether or not the one or more success criteria are fulfilled.

The control unit <NUM> may be configured to, e.g. by means of a triggering unit <NUM> in the control unit <NUM>, when the one or more success criteria are fulfilled, trigger a performance increase of the combustion engine <NUM>.

The embodiments herein may be implemented through a processor or one or more processors, such as the processor <NUM> of a processing circuitry in the control unit <NUM> depicted in <FIG>, together with computer program code for performing the functions and actions of the embodiments herein. The program code mentioned above may also be provided as a computer program medium, for instance in the form of a data computer readable medium carrying computer program code for performing the embodiments herein when being loaded into the control unit <NUM>. One such computer readable medium may be in the form of a memory stick. The computer program code may furthermore be provided as pure program code on a server and downloaded to the control unit <NUM>.

The control unit <NUM> may further comprise a memory <NUM> comprising one or more memory units. The memory <NUM> comprises instructions executable by the processor in control unit <NUM>. The memory <NUM> is arranged to be used to store e.g. information, indications, data, configurations, functions, models, pre-heating statistics, success criteria, and applications to perform the methods herein when being executed in the control unit <NUM>. The memory <NUM> may in some embodiments comprise the storage medium <NUM>.

In some embodiments, a computer program <NUM> comprises instructions, which when executed by the at least one processor <NUM>, cause the at least one processor of the control unit <NUM> to perform the actions <NUM>-<NUM> above.

In some embodiments, a computer-readable storage medium <NUM> comprises the respective computer program <NUM>. The computer-readable storage medium <NUM> may comprise program code for performing the steps of actions <NUM>-<NUM> above when said program product is run on the at least one processor <NUM>.

Those skilled in the art will appreciate that the units in the control unit <NUM> described above may refer to a combination of analogue and digital circuits, and/or one or more processors configured with software and/or firmware, e.g. stored in the control unit <NUM>, that when executed by the respective one or more processors such as the processors described above. One or more of these processors, as well as the other digital hardware, may be included in a single Application-Specific Integrated Circuitry (ASIC), or several processors and various digital hardware may be distributed among several separate components, whether individually packaged or assembled into a system-on-a-chip (SoC).

Claim 1:
A method performed by a control unit (<NUM>) in connection with a pre-heating process of an aftertreatment system (<NUM>) for a combustion engine (<NUM>), the method comprising:
- obtaining (<NUM>) a scheduled start time of the combustion engine (<NUM>),
- scheduling (<NUM>) a pre-heating of the aftertreatment system (<NUM>) to be completed before the scheduled start time,
- detecting (<NUM>) a start of the combustion engine (<NUM>) at an actual start time,
- in response to the detected start of the combustion engine (<NUM>), and using the actual and scheduled start times, determining (<NUM>) whether the scheduled pre-heating of the aftertreatment system (<NUM>) fulfils one or more success criteria, wherein the one or more success criteria comprise that the actual start time is later than or coincides with the scheduled start time,
- obtaining pre-heating (<NUM>) statistics indicating whether or not the one or more success criteria was fulfilled at one or more previous starts of the combustion engine (<NUM>),
- when the one or more success criteria are fulfilled, triggering (<NUM>) a performance increase of the combustion engine (<NUM>) based on the obtained pre-heating statistics.