EP4650579A1

EP4650579A1 - System and method for operating an internal combustion engine system during cold start

Info

Publication number: EP4650579A1
Application number: EP24175394.6A
Authority: EP
Inventors: Johan CARLÉN ANDERSSON; Fredrik Rahm
Original assignee: Volvo Truck Corp
Current assignee: Volvo Truck Corp
Priority date: 2024-05-13
Filing date: 2024-05-13
Publication date: 2025-11-19

Abstract

The present disclosure relates to a method for operating an internal combustion engine system (200) for a vehicle (1), the internal combustion engine system (200) comprising an internal combustion engine (201), an electric machine (202) arranged to selectively rotate the combustion engine (201), an exhaust aftertreatment system, EATS, (203) and an EATS heater (204) arranged upstream of the EATS, the method comprising:
detect a cold start event when the internal combustion engine is unfired;
upon detection of a cold start event, control the internal combustion engine system (200) to a cold start mode, wherein in said cold start mode the EATS heater (204) is controlled to heat the EATS (203) and the electric machine (202) is controlled to rotate the unfired internal combustion engine (201), thereby pumping air from the internal combustion engine (201) to the EATS (203) via the EATS heater (204).

Description

TECHNICAL FIELD

The disclosure relates generally to exhaust aftertreatment. In particular aspects, the disclosure relates to a computer system and a computer-implemented method for operating an internal combustion engine system, an internal combustion engine system, and a vehicle. The disclosure can be applied to heavy-duty vehicles, such as trucks, buses, and construction equipment, among other vehicle types. In some non-limiting examples, the disclosure may be applied to hybrid vehicles, with an electric drive and an internal combustion engine. Although the disclosure may be described with respect to a particular vehicle, the disclosure is not restricted to any particular vehicle.

BACKGROUND

Increasingly stricter emission legislation puts high demands on emission performance, not only during the predominant operating conditions, but also during the more infrequent operating conditions such as cold starts. Cold starts may be problematic, since the exhaust aftertreatment system (EATS), in particular the selective catalytic reduction (SCR) component, does not operate efficiently at low temperatures, which may lead to increased emissions. Existing methods of pre-heating the combustion engine and the EATS are often time- and/or energy-consuming or require dedicated components.
Hence, there is a need for improved methods and systems for operating an internal combustion engine system comprising an EATS during cold start. In particular, there is a need for systems and methods allowing for cost-efficient and fast emission control during cold start events.

SUMMARY

According to a first aspect of the disclosure, there is provided a computer system for operating an internal combustion engine system for a vehicle, the internal combustion engine system comprising an internal combustion engine, an electric machine arranged to selectively rotate the combustion engine, an exhaust aftertreatment system, EATS, and an EATS heater arranged upstream of the EATS, the computer system comprising processing circuitry configured to:

detect a cold start event when the internal combustion engine is unfired;
upon detection of a cold start event, control the internal combustion engine system to a cold start mode, wherein in said cold start mode the EATS heater is controlled to heat the EATS and the electric machine is controlled to rotate the unfired internal combustion engine, thereby pumping air from the internal combustion engine to the EATS via the EATS heater. The first aspect of the disclosure may seek to improve the emission performance of the vehicle. In particular, the first aspect of the disclosure may seek to improve the emission performance of the vehicle during cold start events. The first aspect seeks to increase the performance of the EATS, which may be highly temperature dependent. For example, the efficiency of a selective catalytic reduction (SCR) component often incorporated in modern EATS may be very low before reaching an operating temperature of around 200°C-300°C. Thus, it is beneficial to warm up the EATS before the internal combustion engine is started. The time needed for the warming up the EATS should be as short as possible, in order to avoid discomfort associated with waiting times. The first aspect of the present disclosure may achieve a decreased time for warming up the EATS before the combustion engine is operated in a fired mode by pumping hot air warmed up by the EATS heater, which is arranged upstream of the EATS, through the EATS. The pumping action is achieved by rotating the combustion engine using an electric machine. A technical benefit may include decreased engine emissions during cold start, such as NOx, CO, or particulate matter (PM). Another benefit may be shortened waiting times before the vehicle can be operated. Still, another technical benefit may include that breaches of emission legislation limits during cold start of the vehicle may be avoided.

Optionally in some examples, including in at least one preferred example, the internal combustion engine comprises at least one cylinder and a variable valve system arranged to control at least one respective intake valve and at least one respective exhaust valve of the at least one respective cylinder, and the processing circuitry is further configured to:

control the variable valve system to be operated in a pumping mode, said pumping mode comprising an intake stroke and an exhaust stroke, wherein during at least parts of said intake stroke, the at least one respective intake valve is controlled to an open state, and wherein during at least parts of said exhaust stroke, the at least one respective exhaust valve is controlled to an open state.

Optionally in some examples, including in at least one preferred example, during said pumping mode, the respective intake valve is controlled to an open state approximately between a top dead center (TDC) position and a bottom dead center (BDC) position of a respective piston during said intake stroke, and the respective exhaust valve is controlled to an open state approximately between the BDC position and the TDC position of the respective piston during said exhaust stroke. A technical benefit may include an increased pumping volume of air, drawn into the respective cylinder and pushed out towards the EATS, at each respective cylinder stroke, thereby the flow of air may be maximized.
Optionally in some examples, including in at least one preferred example, the intake stroke is directly followed by the exhaust stroke, and vice versa. Hence, the compression stroke and the power stroke usually present in a four-stroke operated internal combustion engine may be skipped, since they are not necessary during the operation of the internal combustion engine for pumping air. In other words, the internal combustion engine may be operated in an unfired two-stroke mode with only an intake stroke and an exhaust stoke. A technical benefit may include increased air flow during the cold start mode. Further, the flow towards the EATS may become more uniform over time since pressure pulses from the compression and expansion may be avoided. A technical effect may further be an improved heating of the EATS due to the increased air flow.
Optionally in some examples, including in at least one preferred example, the processing circuitry is further configured to:
control the speed of the electric machine during the cold start mode based on one or more of:

a temperature of the EATS;
a temperature of the EATS heater;
an ambient temperature;
a stand-still time and/or a running history of the vehicle.

Optionally in some examples, including in at least one preferred example, the internal combustion engine system comprises one or more temperature sensors arranged to measure a temperature of the EATS and/or the EATS heater. A technical benefit may include an improved control of the internal combustion engine during the cold start mode enabling a more energy-efficient warm up of the EATS.
Optionally in some examples, including in at least one preferred example, the processing circuitry is further configured to:

calculate the temperature of the EATS and/or the temperature of the EATS heater based on the ambient temperature and a heat-transfer model for the internal combustion engine system. A technical benefit may include a more accurate temperature indication since measuring inside the EATS and/or the EATS heater is difficult.

Optionally in some examples, including in at least one preferred example, the speed of the electric machine during the cold start mode is controlled according to a predetermined speed map over time. For example, the predetermined speed map over time may include a first time period with a relatively low speed, followed by a ramping up of the speed of the electric machine during a second time period, followed by a third time period with a constant high speed, and so on. A technical benefit may include a simple and robust control of the electric machine is provided.
Optionally in some examples, including in at least one preferred example, the processing circuitry is further configured to:

detect that the EATS has reached a sufficient operation temperature exceeding an operating temperature threshold; and
upon detection of a sufficient operation temperature of the EATS, abandon the cold start mode and start normal fired operation of the internal combustion engine. Thereby, an end time point for the cold start mode may be determined reliably, while at the same time ensuring that the EATS has reached a temperature sufficient for emission control.

According to a second aspect of the disclosure, there is provided an internal combustion engine system comprising an internal combustion engine, an electric machine, an exhaust aftertreatment system, EATS, an EATS heater and the computer system according to the first aspect. Advantages and advantageous features of the internal combustion engine system according to the second aspect are largely analogous to advantages and advantageous features of the computer system according to the first aspect.
Optionally in some examples, including in at least one preferred example, the combustion engine comprises at least one cylinder and a variable valve system arranged to control at least one respective intake valve and at least one respective exhaust valve of the at least one respective cylinder.
Optionally in some examples, including in at least one preferred example, the EATS heater is an electric heater arranged upstream of the EATS. Thereby, an environmentally friendly heating of the EATS may be achieved.
Optionally in some examples, including in at least one preferred example, the EATS heater is a fuel burner arranged upstream of the EATS. Thereby, a heating of the EATS may be provided which is independent of any electric energy supply.
Optionally in some examples, including in at least one preferred example, the vehicle comprises an intake heater arranged upstream of the combustion engine and wherein the processing circuitry is further configured to:
control the intake heater to heat the intake air during the cold start mode. A technical benefit may include an improved warm up of the combustion engine, which may also contribute to the warm-up of the EATS.
According to a third aspect of the disclosure, there is provided a vehicle comprising an internal combustion engine system according to the second aspect. Advantages and advantageous features of the vehicle according to the third aspect are largely analogous to advantages and advantageous features of the computer system according to the first aspect.
According to a fourth aspect, there is provided a computer-implemented method for operating an internal combustion engine system for a vehicle, the internal combustion engine system comprising an internal combustion engine, an electric machine arranged to selectively rotate the combustion engine, an exhaust aftertreatment system, EATS, and an EATS heater arranged upstream of the EATS, the method comprising:

detecting, by processing circuitry of a computer system, a cold start event, when the internal combustion engine is unfired;
upon detection of a cold start event, controlling, by the processing circuitry, the vehicle to a cold start mode, wherein in said cold start mode the EATS heater is controlled to heat the EATS and the electric machine is controlled to rotate the unfired internal combustion engine, thereby pumping air from the combustion engine to the EATS via the EATS heater. Advantages and advantageous features of the method according to the fourth aspect are largely analogous to advantages and advantageous features of the computer system according to the first aspect.

Optionally in some examples, including in at least one preferred example, the combustion engine comprises at least one cylinder and a variable valve system arranged to control at least one respective intake valve and at least one respective exhaust valve of the at least one respective cylinder, and wherein the method further comprises:

controlling, by the processing circuitry, the variable valve system to be operated in a pumping mode, said pumping mode comprising an intake stroke and an exhaust stroke, wherein during at least parts of said intake stroke, the at least one respective intake valve is controlled to an open state, and wherein during at least parts of said exhaust stroke, the at least one respective exhaust valve is controlled to an open state.

Optionally in some examples, including in at least one preferred example, the intake stroke is directly followed by the exhaust stroke, and vice versa.
Optionally in some examples, including in at least one preferred example, the method further comprises:

detecting, by the processing circuitry, that the EATS has reached a sufficient operation temperature exceeding an operating temperature threshold; and
upon detection of a sufficient operation temperature of the EATS, abandoning, by the processing circuitry, the cold start mode and starting normal fired operation of the internal combustion engine.

According to a fifth aspect, there is provided a computer program product comprising program code for performing, when executed by the processing circuitry, the method of the fourth aspect.
According to a sixth aspect, there is provided a non-transitory computer-readable storage medium comprising instructions, which when executed by the processing circuitry, cause the processing circuitry to perform the method of the fourth aspect.
The disclosed aspects, examples (including any preferred examples), and/or accompanying claims may be suitably combined with each other as would be apparent to anyone of ordinary skill in the art. Additional features and advantages are disclosed in the following description, claims, and drawings, and in part will be readily apparent therefrom to those skilled in the art or recognized by practicing the disclosure as described herein.
There are also disclosed herein computer systems, control units, code modules, computer-implemented methods, computer readable media, and computer program products associated with the above discussed technical benefits.

BRIEF DESCRIPTION OF THE DRAWINGS

Examples are described in more detail below with reference to the appended drawings.

FIG. 1 is a schematic side view of a vehicle according to an example.
FIG. 2 schematically shows an internal combustion engine system according to examples.
FIG. 3 is a flow chart illustrating a method according to an example.
FIG. 4 is a schematic diagram of an exemplary computer system for implementing examples disclosed herein, according to an example.

DETAILED DESCRIPTION

The detailed description set forth below provides information and examples of the disclosed technology with sufficient detail to enable those skilled in the art to practice the disclosure.
An aim of the present disclosure is to alleviate at least one drawback of the prior art, or at least to provide a suitable alternative. In particular, an aim of the present disclosure is to provide an improved emission control during cold start events. In particular aspects, the disclosure aims for bringing the EATS of a vehicle to a sufficient operation control in a shorter time and/or using less energy.
FIG. 1 schematically depicts a vehicle 1 in the form of a heavy-duty towing truck. The vehicle 1 comprises an internal combustion engine system 200 with an internal combustion engine (not shown) and an electric machine (not shown) in the form of a motor/generator, wherein both the combustion engine and the electric machine may be used for propulsion of the vehicle 1 or wherein the electric machine is a starter motor only intended for engine start up. A computer system 400 is provided for operating the vehicle 1, such as for operating the internal engine combustion system 200.
FIG. 2 shows an internal combustion engine system 200 of a vehicle 1, such as of the vehicle 1 illustrated in FIG. 1. The internal combustion engine system 200 comprises an internal combustion engine 201, an electric machine 202 arranged to selectively rotate the combustion engine 201, an exhaust aftertreatment system, EATS, 203 and an EATS heater 204 arranged upstream of the EATS. The internal combustion engine 201 depicted in Fig. 2 is equipped with four cylinders 213, each of which has its respective intake valves 211 and exhaust valves 212. However, any other numbers of cylinders may be used depending on the engine configuration. The combustion engine system 200 may further comprise a variable valve system 210, for variably controlling the intake 211 and exhaust valves 212. As non-limiting examples, the variable valve system 210 may be actuated electrically, pneumatically or by way of a cam shaft. The variable valve system 210 may allow for an adapted valve timing, with the aim of pumping air from the internal combustion engine 201 towards the EATS 203 during engine start up. In one example the variable valve system 210 of an engine brake system may be used during the cold start mode.
Although the illustrated engine combustion system 200 comprises a single electric machine 202, it may in other examples comprise two or more electric machines. The combustion engine 201 may be a diesel engine configured to use diesel as a fuel, but it may in other examples be configured to use other fuels, such as bio-fuel, gasoline, or hydrogen. The electric machine 202 may be an electric motor for propulsion of the vehicle 1. In that case the vehicle may be a hybrid vehicle. In other examples, the electric machine may be a starter motor normally used for starting the internal combustion engine 201.
By the electric machine 202 being arranged to selectively rotate the combustion engine 201 means herein that the electric machine is arranged to selectively rotate the combustion engine 201 such that a piston is moving back and forth in each respective cylinder. For example, the electric machine 202 may be arranged to rotate a crankshaft (not shown) such that the piston is moved in the respective cylinder.
The EATS 203 is arranged in an exhaust flow path from the combustion engine 201. The EATS 203 may comprise a number of components (not shown) for reducing hazardous emissions from the combustion engine 201. As nonlimiting examples, the EATS may comprise an oxidation catalyst component (not shown), such as a Diesel Oxidation Catalyst (DOC) component (not shown), a particulate filter (PF) (not shown), such as a Diesel Particulate Filter (not shown), and a Selective Catalytic Reduction (SCR) component (not shown).
The illustrated internal combustion engine system 200 further comprises an EATS heater 204 arranged upstream of the EATS 203. "Upstream" herein means in a direction counter to the flow of exhaust gas from the internal combustion engine 201 to the EATS 203. The EATS heater 204 may be an electrical heating element configured to be heated by means of electricity or may be a fuel burner. The EATS heater 204 may comprise a resistive heating element, or an induction heating element, or a Positive Temperature Coefficient, PTC, based element. The EATS heater 204 may comprise a heated component positioned in the fluid flow path, such as a lattice, a grating, a coil, or a plate.
Furthermore, although not illustrated, one or more sensors, e.g., at least one temperature sensor, may be provided in the internal combustion engine system 200. The temperature sensor(s) may, purely by way of example, be arranged to measure a temperature of the SCR component, and/or of the exhaust gases upstream of the SCR component. Further temperature sensors may be arranged for monitoring the temperature of the internal combustion engine 201 or related parts, the intake air or the ambient temperature. The temperatures at different points of the internal combustion engine system 200, such as inside the SCR component or the EATS heater, may also be obtained by a heat transfer model, used to estimate the respective temperatures based on an operation history of the internal combustion engine 201, the EATS heater, an intake heater, ambient temperatures, or temperatures measured at other positions of the internal combustion engine system 200. The heat transfer model may also include thermal masses of the different EATS components.
As mentioned before, some of the EATS components, in particular the SCR component, are not efficiently working before reaching their operating temperatures. An SCR component, e.g., may start to convert NOx after reaching an operating temperature of around 200°C. Thereafter, the conversion efficiency increases until it reaches a maximum at around 300°C. Thus, the EATS 203 is working far from optimally during cold starts. For improving the cold start performance of the vehicle 1, an electronic control unit 150 is provided for controlling, by way of example, operation of the combustion engine 201, the electric machine 202, and, optionally, the variable valve system 210. The electronic control unit 150 may form part of the computer system 400 as illustrated in FIG. 1. The electronic control unit 150 may preferably be located within the vehicle 1.
A computer-implemented method for operating a vehicle 1, such as the vehicle 1 illustrated in FIG. 1 comprising the internal combustion engine system 200 illustrated in FIG. 2, is illustrated in FIG. 3 . The method may be carried out by processing circuity of a computer system 400, such as within the control unit 150 illustrated in FIG. 2. The method comprises the actions illustrated in FIG. 3, wherein optional actions are illustrated with dashed lines.
Action S1: Detecting a cold start event when the internal combustion engine 201 is unfired. The electronic control unit 150 comprises processing circuitry configured to detect a cold start event. A cold start event may be detected depending on a temperature indicative of a current engine temperature, an ambient temperature, and/or a history of vehicle operation, e.g., indicating that the internal combustion engine has not been operated in a fired operation mode for a certain amount of time.
Action S2: Upon detection of a cold start event, controlling the vehicle 1 to a cold start mode, wherein in said cold start mode the EATS heater 204 is controlled to heat the EATS 203 and the electric machine 202 is controlled to rotate the unfired internal combustion engine 201, thereby pumping air from the combustion engine 201 to the EATS 203 via the EATS heater 204. When rotating the unfired internal combustion engine 201 using the electric machine 202, even without further modification of the valve timing, air is drawn into the cylinders during an intake stroke and expelled during an exhaust stroke. Thus, a pumping action may be achieved which pushes air from the internal combustion engine 201 and through the EATS 203. The speed of the electric machine 202 during the cold start mode may be controlled based on a feedback control taking into account states of the vehicle 1, the internal combustion engine system 200 and/or the EATS 203. For example, the speed of the electric machine 202, and consequently the speed of the internal combustion engine 201 may be controlled based on a temperature of the EATS 203, a temperature of the EATS heater 204, an ambient temperature, a stand-still time, and/or a running history of the vehicle 1. Hence, the speed of the electric machine 202 may be controlled during the cold start mode such that an optimal heat transfer to the EATS 203 is provided, while at the same time not using unnecessarily much energy to rotate the combustion engine 201. As a non-limiting example, the speed of the electric machine 202 may be controlled to a relatively low speed while the temperature of the EATS heater 204 is low to avoid pumping cold air towards the EATS 203 and unnecessary energy consumption for rotating the internal combustion engine 201. As another example, the speed of the electric machine 202 during the cold start mode may be controlled to a relatively high speed when the vehicle 1 has been operated within a certain time period, e.g., 5 or 10 minutes, which may indicate that the combustion engine 201 and related parts of the exhaust system are still warm from the previous operation. Another way of operating the electric machine 202 during the cold start mode may be to control the speed of the electric machine 202 in a feed-forward manner, i.e., by controlling it according to a predetermined speed map over time. For example, the speed of the electric machine may start relatively low for a first time period, followed by a second time period where the speed of the electric machine 202 is ramped up to a relatively high speed, followed by a third time period with a constant relatively high speed, and so on. The speed map may include any number of different speed levels for different time periods appropriate for an optimized heat up of the EATS 203 with the aim of minimizing the energy used to operate the electric machine 202.
For improving the pumping efficiency, the method may optionally comprise the following action S3:
Action S3: controlling the variable valve system 210 to be operated in a pumping mode, said pumping mode comprising an intake stroke and an exhaust stroke, wherein during at least parts of said intake stroke, the at least one respective intake valve 211 is controlled to an open state, and wherein during at least parts of said exhaust stroke, the at least one respective exhaust valve 212 is controlled to an open state. The valve timing in the pumping mode may be tuned to maximize the amount of air pumped by the internal combustion engine 201. For example, the intake valves 211 may be opened earlier and/or faster than in normal fired operation. In some examples, the intake valves 211 may be controlled to open approximately at a top dead center position of the respective cylinder 213 and to close at a bottom dead center position of the respective cylinder 213. Accordingly, the exhaust valves 212 may be controlled to open approximately at the bottom dead center position of the respective cylinder and to close at the top dead center position of the respective cylinder. Thereby, flow losses may be avoided and a more efficient pumping mode may be achieved. In an example, the intake stroke may be directly followed by the exhaust stroke and vice versa. In other words, the compression stroke and the power stroke of a normal fired operation are skipped. Thereby, flow resistances for compressing and expanding air in the cylinders are avoided and a more efficient pumping action of the internal combustion engine 201 may be achieved.
Optionally, the method may further comprise the following actions:

Action S4: Detecting, by the processing circuitry, that the EATS 203 has reached a sufficient operation temperature exceeding an operating temperature threshold. By detecting that a sufficient operation temperature has been reached, it may be ensured that the vehicle may be driven by the internal combustion engine 201 without causing excessive engine emissions. The temperature of the EATS 203 may be detected or indicated by appropriate temperature sensors at the EATS 203 or other suitable positions. Alternatively or additionally, the temperature of the EATS 203 may be calculated based on a heat transfer model of the EATS. The heat transfer model may be based on one or more of an ambient temperature, a thermal mass of the EATS and/or other components of the internal combustion engine system, operating states or operating history of the internal combustion engine 201, and operating states and operating history of the EATS heater 204.
Action S5: upon detection of a sufficient operation temperature of the EATS 203, abandoning, by the processing circuitry 402, the cold start mode and starting normal fired operation of the internal combustion engine 201. When a sufficient operation temperature has been reached, the vehicle 1 can be operated in the normal fired operation without the risk of increased emissions.

FIG. 4 is a schematic diagram of a computer system 400 for implementing examples disclosed herein. The computer system 400 is adapted to execute instructions from a computer-readable medium to perform these and/or any of the functions or processing described herein. The computer system 400 may be connected (e.g., networked) to other machines in a LAN (Local Area Network), LIN (Local Interconnect Network), automotive network communication protocol (e.g., FlexRay), an intranet, an extranet, or the Internet. While only a single device is illustrated, the computer system 400 may include any collection of devices that individually or jointly execute a set (or multiple sets) of instructions to perform any one or more of the methodologies discussed herein. Accordingly, any reference in the disclosure and/or claims to a computer system, computing system, computer device, computing device, control system, control unit, electronic control unit (ECU), processor device, processing circuitry, etc., includes reference to one or more such devices to individually or jointly execute a set (or multiple sets) of instructions to perform any one or more of the methodologies discussed herein. For example, control system may include a single control unit or a plurality of control units connected or otherwise communicatively coupled to each other, such that any performed function may be distributed between the control units as desired. Further, such devices may communicate with each other or other devices by various system architectures, such as directly or via a Controller Area Network (CAN) bus, etc.
The computer system 400 may comprise at least one computing device or electronic device capable of including firmware, hardware, and/or executing software instructions to implement the functionality described herein. The computer system 400 may include processing circuitry 402 (e.g., processing circuitry including one or more processor devices or control units, such as the control unit 150 illustrated in FIG. 2), a memory 404, and a system bus 406. The computer system 400 may include at least one computing device having the processing circuitry 402. The system bus 406 provides an interface for system components including, but not limited to, the memory 404 and the processing circuitry 402. The processing circuitry 402 may include any number of hardware components for conducting data or signal processing or for executing computer code stored in memory 404. The processing circuitry 402 may, for example, include a general-purpose processor, an application specific processor, a Digital Signal Processor (DSP), an Application Specific Integrated Circuit (ASIC), a Field Programmable Gate Array (FPGA), a circuit containing processing components, a group of distributed processing components, a group of distributed computers configured for processing, or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described herein. The processing circuitry 402 may further include computer executable code that controls operation of the programmable device.
The system bus 406 may be any of several types of bus structures that may further interconnect to a memory bus (with or without a memory controller), a peripheral bus, and/or a local bus using any of a variety of bus architectures. The memory 404 may be one or more devices for storing data and/or computer code for completing or facilitating methods described herein. The memory 404 may include database components, object code components, script components, or other types of information structure for supporting the various activities herein. Any distributed or local memory device may be utilized with the systems and methods of this description. The memory 404 may be communicably connected to the processing circuitry 402 (e.g., via a circuit or any other wired, wireless, or network connection) and may include computer code for executing one or more processes described herein. The memory 404 may include non-volatile memory 408 (e.g., read-only memory (ROM), erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), etc.), and volatile memory 410 (e.g., random-access memory (RAM)), or any other medium which can be used to carry or store desired program code in the form of machine-executable instructions or data structures and which can be accessed by a computer or other machine with processing circuitry 402. A basic input/output system (BIOS) 412 may be stored in the non-volatile memory 408 and can include the basic routines that help to transfer information between elements within the computer system 400.
The computer system 400 may further include or be coupled to a non-transitory computer-readable storage medium such as the storage device 414, which may comprise, for example, an internal or external hard disk drive (HDD) (e.g., enhanced integrated drive electronics (EIDE) or serial advanced technology attachment (SATA)), HDD (e.g., EIDE or SATA) for storage, flash memory, or the like. The storage device 414 and other drives associated with computer-readable media and computer-usable media may provide non-volatile storage of data, data structures, computer-executable instructions, and the like.
Computer-code which is hard or soft coded may be provided in the form of one or more modules. The module(s) can be implemented as software and/or hard-coded in circuitry to implement the functionality described herein in whole or in part. The modules may be stored in the storage device 414 and/or in the volatile memory 410, which may include an operating system 416 and/or one or more program modules 418. All or a portion of the examples disclosed herein may be implemented as a computer program 420 stored on a transitory or non-transitory computer-usable or computer-readable storage medium (e.g., single medium or multiple media), such as the storage device 414, which includes complex programming instructions (e.g., complex computer-readable program code) to cause the processing circuitry 402 to carry out actions described herein. Thus, the computer-readable program code of the computer program 420 can comprise software instructions for implementing the functionality of the examples described herein when executed by the processing circuitry 402. In some examples, the storage device 414 may be a computer program product (e.g., readable storage medium) storing the computer program 420 thereon, where at least a portion of a computer program 420 may be loadable (e.g., into a processor) for implementing the functionality of the examples described herein when executed by the processing circuitry 402. The processing circuitry 402 may serve as a controller or control system for the computer system 400 that is to implement the functionality described herein.
The computer system 400 may include an input device interface 422 configured to receive input and selections to be communicated to the computer system 400 when executing instructions, such as from a keyboard, mouse, touch-sensitive surface, etc. Such input devices may be connected to the processing circuitry 402 through the input device interface 422 coupled to the system bus 406 but can be connected through other interfaces, such as a parallel port, an Institute of Electrical and Electronic Engineers (IEEE) 1394 serial port, a Universal Serial Bus (USB) port, an IR interface, and the like. The computer system 400 may include an output device interface 424 configured to forward output, such as to a display, a video display unit (e.g., a liquid crystal display (LCD) or a cathode ray tube (CRT)). The computer system 400 may include a communications interface 426 suitable for communicating with a network as appropriate or desired.
The operational actions described in any of the exemplary aspects herein are described to provide examples and discussion. The actions may be performed by hardware components, may be embodied in machine-executable instructions to cause a processor to perform the actions, or may be performed by a combination of hardware and software. Although a specific order of method actions may be shown or described, the order of the actions may differ. In addition, two or more actions may be performed concurrently or with partial concurrence.
The terminology used herein is for the purpose of describing particular aspects only and is not intended to be limiting of the disclosure. As used herein, the singular forms "a," "an," and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items. It will be further understood that the terms "comprises," "comprising," "includes," and/or "including" when used herein specify the presence of stated features, integers, actions, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, actions, steps, operations, elements, components, and/or groups thereof.
It will be understood that, although the terms first, second, etc., may be used herein to describe various elements, these elements should not be limited by these terms. These terms are only used to distinguish one element from another. For example, a first element could be termed a second element, and, similarly, a second element could be termed a first element without departing from the scope of the present disclosure.
Relative terms such as "below" or "above" or "upper" or "lower" or "horizontal" or "vertical" may be used herein to describe a relationship of one element to another element as illustrated in the Figures. It will be understood that these terms and those discussed above are intended to encompass different orientations of the device in addition to the orientation depicted in the Figures. It will be understood that when an element is referred to as being "connected" or "coupled" to another element, it can be directly connected or coupled to the other element, or intervening elements may be present. In contrast, when an element is referred to as being "directly connected" or "directly coupled" to another element, there are no intervening elements present.
Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs. It will be further understood that terms used herein should be interpreted as having a meaning consistent with their meaning in the context of this specification and the relevant art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.
It is to be understood that the present disclosure is not limited to the aspects described above and illustrated in the drawings; rather, the skilled person will recognize that many changes and modifications may be made within the scope of the present disclosure and appended claims. In the drawings and specification, there have been disclosed aspects for purposes of illustration only and not for purposes of limitation, the scope of the disclosure being set forth in the following claims.
In the following, possible features and feature combinations of the present disclosure are presented as a list of numbered Examples.
Example 1: A computer system (400) for operating an internal combustion engine system (200) for a vehicle (1), the internal combustion engine system (200) comprising an internal combustion engine (201), an electric machine (202) arranged to selectively rotate the combustion engine (201), an exhaust aftertreatment system, EATS, (203) and an EATS heater (204) arranged upstream of the EATS, the computer system (400) comprising processing circuitry (402) configured to:

detect a cold start event when the internal combustion engine is unfired;
upon detection of a cold start event, control the internal combustion engine system (200) to a cold start mode, wherein in said cold start mode the EATS heater (204) is controlled to heat the EATS (203) and the electric machine (202) is controlled to rotate the unfired internal combustion engine (201), thereby pumping air from the internal combustion engine (201) to the EATS (203) via the EATS heater (204).

Example 2: The computer system of example 1, wherein the internal combustion engine comprises at least one cylinder (213) and a variable valve system (210) arranged to control at least one respective intake valve (211) and at least one respective exhaust valve (212) of the at least one respective cylinder (213), and wherein the processing circuitry (402) is further configured to

control the variable valve system (210) to be operated in a pumping mode, said pumping mode comprising an intake stroke and an exhaust stroke, wherein during at least parts of said intake stroke, the at least one respective intake valve (211) is controlled to an open state, and wherein during at least parts of said exhaust stroke, the at least one respective exhaust valve (212) is controlled to an open state.

Example 3: The computer system of example 2, wherein during said pumping mode, the respective intake valve (211) is controlled to an open state approximately between a top dead center (TDC) position and a bottom dead center (BDC) position of a respective piston during said intake stroke, and
the respective exhaust valve (212) is controlled to an open state approximately between the BDC position and the TDC position of the respective piston during said exhaust stroke.
Example 4: The computer system of any of examples 2-3, wherein the intake stroke is directly followed by the exhaust stroke, and vice versa.
Example 5: The computer system of any of examples 1-4, wherein the processing circuitry (402) is further configured to:
control the speed of the electric machine (202) during the cold start mode based on one or more of:

a temperature of the EATS (203);
a temperature of the EATS heater (204);
an ambient temperature;
a stand-still time and/or a running history of the vehicle (1).

Example 6: The computer system of example 5, wherein the internal combustion engine system (200) comprises one or more temperature sensors arranged to measure a temperature of the EATS (203) and/or the EATS heater (204).
Example 7: The computer system of example 5, wherein the processing circuitry (402) is further configured to:

calculate the temperature of the EATS and/or the temperature of the EATS heater based on the ambient temperature and a heat-transfer model for the internal combustion engine system (200).

Example 8: The computer system of any of examples 1-4, wherein the speed of the electric machine (202) during the cold start mode is controlled according to a predetermined speed map over time.
Example 9: The computer system of any of examples 1-8, wherein the processing circuitry (402) is further configured to:

detect that the EATS (203) has reached a sufficient operation temperature exceeding an operating temperature threshold;
upon detection of a sufficient operation temperature of the EATS (203), abandon the cold start mode and start normal fired operation of the internal combustion engine.

Example 10: The internal combustion engine system of any of examples 1-9, wherein the vehicle (1) comprises an intake heater arranged upstream of the combustion engine and wherein the processing circuitry is further configured to:
control the intake heater to heat the intake air during the cold start mode.
Example 11: An internal combustion engine system (1) comprising an internal combustion engine, an electric machine, an exhaust aftertreatment system, EATS, an EATS heater and the computer system of any of examples 1-10.
Example 12: The internal combustion engine system of example 11, wherein the combustion engine comprises at least one cylinder and a variable valve system arranged to control at least one respective intake valve and at least one respective exhaust valve of the at least one respective cylinder.
Example 13: The internal combustion engine system of any of examples 11-12, wherein the EATS heater (204) is an electric heater arranged upstream of the EATS (203).
Examples 14: The internal combustion engine system of any of examples 11-12, wherein the EATS heater (204) is a fuel burner arranged upstream of the EATS (203).
Example 15: A vehicle comprising an internal combustion engine system according to any one of examples 10-14.
Example 16: A computer-implemented method for operating an internal combustion engine system (200) for a vehicle (1), the internal combustion engine system comprising an internal combustion engine (201), an electric machine (202) arranged to selectively rotate the combustion engine (201), an exhaust aftertreatment system, EATS, (203) and an EATS heater (204) arranged upstream of the EATS (203), comprising:

detecting (S1), by processing circuitry (402) of a computer system (400), a cold start event, when the internal combustion engine is unfired; and
upon detection of a cold start event, controlling (S2), by the processing circuitry (402), the vehicle (1) to a cold start mode, wherein in said cold start mode the EATS heater (204) is controlled to heat the EATS (203) and the electric machine (202) is controlled to rotate the unfired internal combustion engine (201), thereby pumping air from the combustion engine (201) to the EATS (203) via the EATS heater (204).

Example 17: The method of example 16, wherein the combustion engine comprises at least one cylinder (213) and a variable valve system (210) arranged to control at least one respective intake valve (211) and at least one respective exhaust valve (212) of the at least one respective cylinder (213), and wherein the method further comprises

controlling (S3), by the processing circuitry (402), the variable valve system (210) to be operated in a pumping mode, said pumping mode comprising an intake stroke and an exhaust stroke, wherein during at least parts of said intake stroke, the at least one respective intake valve (211) is controlled to an open state, and wherein during at least parts of said exhaust stroke, the at least one respective exhaust valve (212) is controlled to an open state.

Example 18: The method of example 17, wherein the intake stroke is directly followed by the exhaust stroke, and vice versa.
Example 19: The method of any of examples 16 or 17, further comprising: detecting (S4), by the processing circuitry, that the EATS (203) has reached a sufficient operation temperature exceeding an operating temperature threshold; upon detection of a sufficient operation temperature of the EATS (203), abandoning (S5), by the processing circuitry (402), the cold start mode and starting normal fired operation of the internal combustion engine (201).
Example 20: A computer program product comprising program code for performing, when executed by the processing circuitry, the method of any of claims 16-19.
Example 21: A non-transitory computer-readable storage medium comprising instructions, which when executed by the processing circuitry, cause the processing circuitry to perform the method of any of examples 16-19.

Claims

A computer system (400) for operating an internal combustion engine system (200) for a vehicle (1), the internal combustion engine system (200) comprising an internal combustion engine (201), an electric machine (202) arranged to selectively rotate the combustion engine (201), an exhaust aftertreatment system, EATS, (203) and an EATS heater (204) arranged upstream of the EATS, the computer system (400) comprising processing circuitry (402) configured to:
detect a cold start event when the internal combustion engine is unfired;

upon detection of a cold start event, control the internal combustion engine system (200) to a cold start mode, wherein in said cold start mode the EATS heater (204) is controlled to heat the EATS (203) and the electric machine (202) is controlled to rotate the unfired internal combustion engine (201), thereby pumping air from the internal combustion engine (201) to the EATS (203) via the EATS heater (204).
The computer system of claim 1, wherein the internal combustion engine comprises at least one cylinder (213) and a variable valve system (210) arranged to control at least one respective intake valve (211) and at least one respective exhaust valve (212) of the at least one respective cylinder (213), and wherein the processing circuitry (402) is further configured to
- control the variable valve system (210) to be operated in a pumping mode, said pumping mode comprising an intake stroke and an exhaust stroke, wherein during at least parts of said intake stroke, the at least one respective intake valve (211) is controlled to an open state, and wherein during at least parts of said exhaust stroke, the at least one respective exhaust valve (212) is controlled to an open state.
The computer system of claim 2, wherein during said pumping mode, the respective intake valve (211) is controlled to an open state approximately between a top dead center (TDC) position and a bottom dead center (BDC) position of a respective piston during said intake stroke, and
the respective exhaust valve (212) is controlled to an open state approximately between the BDC position and the TDC position of the respective piston during said exhaust stroke.
The computer system of any of claims 2-3, wherein the intake stroke is directly followed by the exhaust stroke, and vice versa.
The computer system of any of claims 1-4, wherein the processing circuitry (402) is further configured to:
control the speed of the electric machine (202) during the cold start mode based on one or more of:
- a temperature of the EATS (203);

- a temperature of the EATS heater (204);

- an ambient temperature;

- a stand-still time and/or a running history of the vehicle (1).
The computer system of any of claims 1-4, wherein the speed of the electric machine (202) during the cold start mode is controlled according to a predetermined speed map over time.
The computer system of any of claims 1-6, wherein the processing circuitry (402) is further configured to:
detect that the EATS (203) has reached a sufficient operation temperature exceeding an operating temperature threshold;

upon detection of a sufficient operation temperature of the EATS (203), abandon the cold start mode and start normal fired operation of the internal combustion engine.
An internal combustion engine system (1) comprising an internal combustion engine, an electric machine, an exhaust aftertreatment system, EATS, an EATS heater and the computer system of any of claims 1-7.
The internal combustion engine system of claim 8, wherein the combustion engine comprises at least one cylinder and a variable valve system arranged to control at least one respective intake valve and at least one respective exhaust valve of the at least one respective cylinder.
A vehicle comprising an internal combustion engine system according to any one of claims 8-9.
A computer-implemented method for operating an internal combustion engine system (200) for a vehicle (1), the internal combustion engine system comprising an internal combustion engine (201), an electric machine (202) arranged to selectively rotate the combustion engine (201), an exhaust aftertreatment system, EATS, (203) and an EATS heater (204) arranged upstream of the EATS (203), comprising:
Detecting (S1), by processing circuitry (402) of a computer system (400), a cold start event, when the internal combustion engine is unfired;

upon detection of a cold start event, controlling (S2), by the processing circuitry (402), the vehicle (1) to a cold start mode, wherein in said cold start mode the EATS heater (204) is controlled to heat the EATS (203) and the electric machine (202) is controlled to rotate the unfired internal combustion engine (201), thereby pumping air from the combustion engine (201) to the EATS (203) via the EATS heater (204).
The method of claim 11, wherein the combustion engine comprises at least one cylinder (213) and a variable valve system (210) arranged to control at least one respective intake valve (211) and at least one respective exhaust valve (212) of the at least one respective cylinder (213), and wherein the method further comprises
- controlling (S3), by the processing circuitry (402), the variable valve system (210) to be operated in a pumping mode, said pumping mode comprising an intake stroke and an exhaust stroke, wherein during at least parts of said intake stroke, the at least one respective intake valve (211) is controlled to an open state, and wherein during at least parts of said exhaust stroke, the at least one respective exhaust valve (212) is controlled to an open state, wherein the intake stroke is directly followed by the exhaust stroke, and vice versa.
The method of any of claim 11 or 12, further comprising:
Detecting (S4), by the processing circuitry, that the EATS (203) has reached a sufficient operation temperature exceeding an operating temperature threshold;

upon detection of a sufficient operation temperature of the EATS (203), abandoning (S5), by the processing circuitry (402), the cold start mode and starting normal fired operation of the internal combustion engine (201).
A computer program product comprising program code for performing, when executed by the processing circuitry, the method of any of claims 11-13.
A non-transitory computer-readable storage medium comprising instructions, which when executed by the processing circuitry, cause the processing circuitry to perform the method of any of claims 11-13.