A computer system and a method for controlling an internal combustion engine

Abstract

A computer system (600) configured to control an internal combustion engine (2) comprising: a first and a second group of engine cylinders (10, 20), an exhaust manifold (4) comprising a first exhaust manifold portion (14) and a second exhaust manifold portion (24), the first exhaust manifold portion being fluidly connectable to an inlet manifold (3) via a valve (15) to enable recirculation of exhaust gases from the first group of engine cylinders, an exhaust aftertreatment system (5) fluidly connected to the exhaust manifold via a pressure regulating device (6), and a fuel injection system (7). The computer system is configured to: - control the valve to be closed, - control the pressure regulating device to create a back pressure, and - control the fuel injection system to inject fuel into the groups of engine cylinders such that combustion is phased earlier in one of the groups than in the other.

Description

[0001] A COMPUTER SYSTEM AND A METHOD FOR CONTROLLING AN INTERNAL COMBUSTION ENGINE

[0002] TECHNICAL FIELD

[0003] [1] The disclosure relates generally to control of internal combustion engines in vehicles. In particular aspects, the disclosure relates to a computer system and a method for controlling an internal combustion engine. The disclosure can be applied to heavy-duty vehicles, such as trucks, buses, and construction equipment, among other vehicle types. Although the disclosure may be described with respect to a particular vehicle, the disclosure is not restricted to any particular vehicle.

[0004] BACKGROUND

[0005] [2] In a vehicle driven by an internal combustion engine, in particular a diesel engine, an exhaust aftertreatment system (EATS) including a selective catalytic reduction (SCR) unit is provided for reducing emissions of, e.g., nitrogen oxides (NOx). The EATS is also provided with a particulate filter (PF) such as a diesel particulate filter (DPF) that traps particulate matter.

[0006] [3] It is desirable to control the temperature within the EATS for several reasons. For example, to maintain NOx emissions at an acceptable level, the temperature of the EATS should be kept within optimal boundaries during operation of the vehicle. In connection with starting of the engine, it is therefore desirable to quickly reach this temperature interval to reduce cold start emissions. Another situation in which it is desirable to increase the temperature within the EATS is when active regeneration of the PF is needed. In such an active regeneration event, soot particles in the PF are burnt in a controlled process when the vehicle is parked.

[0007] SUMMARY

[0008] [4] According to a first aspect of the disclosure, a computer system comprising processing circuitry configured to control an internal combustion engine is provided. The internal combustion engine comprises: a first and a second group of engine cylinders, an inlet manifold, an exhaust manifold comprising a first exhaust manifold portion fluidly connected to the first group of engine cylinders and a second exhaust manifold portion fluidly connected to the second group of engine cylinders, the first exhaust manifold portion being fluidly connectable to the inlet manifold via a first valve to enable recirculation of exhaust gases from the first group of engine cylinders, an exhaust aftertreatment system fluidly connected to the exhaust manifold via a pressure regulating device, a fuel injection system configured to inject fuel into the first and second groups of engine cylinders, the processing circuitry being configured to: control the first valve to a closed valve position, control the pressure regulating device to create a back pressure within the exhaust manifold, and control the fuel injection system to inject fuel into the first and second groups of engine cylinders such that combustion is phased earlier in one of the groups of engine cylinders than in the other group of engine cylinders.

[0009] [5] The first aspect of the disclosure may seek to provide an in at least some aspect improved computer system for controlling an internal combustion engine. In particular, it may seek to provide such a system that may be used to heat up the exhaust system of the engine, and components of the exhaust aftertreatment system, EATS. A technical benefit may include achievement of operating conditions suitable for active regeneration of the particulate filter, PF, in vehicles that rarely operate at an engine power that results is sufficient temperatures for passive PF regeneration. Another technical benefit may include reduced cold start emissions thanks to that optimal temperature conditions for NOx reduction within a selective catalytic reduction, SCR, unit of the aftertreatment system may be reached relatively fast.

[0010] [6] Optionally in some examples, including in at least one preferred example, the processing circuitry is configured to control the fuel injection system to inject the fuel such that combustion is phased earlier in the first group of engine cylinders than in the second group of engine cylinders. A technical benefit may include that advantageous conditions for active PF regeneration may be achieved, as well as an efficient warming of the engine during cold start.

[0011] [7] Optionally in some examples, including in at least one preferred example, the processing circuitry is further configured to control the fuel injection system to inject a smaller amount of fuel into the first group of engine cylinders than into the second group of engine cylinders. By injecting less fuel into the first group of engine cylinders, a pressure reduction in the first exhaust manifold portion may be possible, reducing the risk of unwanted leakage of exhaust gases from the first exhaust manifold portion via the first valve. By injecting more fuel into the second group of engine cylinders, the temperature of the exhaust gases forced into the EATS can be increased, thereby improving the conditions for PF regeneration.

[0012] [8] Optionally in some examples, including in at least one preferred example, the processing circuitry is configured to control the fuel injection system to inject fuel into the first group of engine cylinders with a fuel injection timing resulting in at least 50 percent of the fuel injected to each engine cylinder being burnt before a top dead centre of the respective engine cylinder. This may result in a quick heating and additional NOx generation suitable for active regeneration of the PF.

[0013] [9] Optionally in some examples, including in at least one preferred example, the processing circuitry is configured to control the fuel injection system to inject fuel into the first group of engine cylinders with a fuel injection timing selected to achieve an engine braking effect. This may be achieved by an earlier fuel injection into the first group of cylinders. A technical benefit may be that the engine temperature may be further increased without increasing a rotational speed of the engine, which is advantageous for the PF regeneration.

[0014]

[0010] Optionally in some examples, including in at least one preferred example, the processing circuitry is further configured to detect that a regeneration condition applies, and in response thereto initiate regeneration of a particulate filter of the exhaust aftertreatment system by performing said control of the first valve, the pressure regulating device, and the fuel injection system. Hence, an active regeneration of the PF may be achieved when needed.

[0015]

[0011] Optionally in some examples, including in at least one preferred example, the processing circuitry is further configured to detect that a cold start condition applies, and in response thereto initiate warming of the exhaust aftertreatment system by performing said control of the first valve, the pressure regulating device, and the fuel injection system, j

[0016]

[0012] Optionally in some examples, including in at least one preferred example, the processing circuitry is further configured to: monitor a temperature within the internal combustion engine, detect that a predetermined temperature criterion is met, and in response thereto control the first valve to an open position.

[0017]

[0013] According to a second aspect of the disclosure, an internal combustion engine is provided. It comprises: a first and a second group of engine cylinders, an inlet manifold, an exhaust manifold comprising a first exhaust manifold portion fluidly connected to the first group of engine cylinders and a second exhaust manifold portion fluidly connected to the second group of engine cylinders, the first exhaust manifold portion being fluidly connectable to the inlet manifold via a first valve to enable recirculation of exhaust gases from the first group of engine cylinders, an exhaust aftertreatment system fluidly connected to the exhaust manifold via a pressure regulating device, a fuel injection system configured to inject fuel into the first and second groups of engine cylinders, and a computer system of the first aspect.

[0018]

[0014] The second aspect of the disclosure may seek to provide an in at least some aspect improved internal combustion engine. A technical benefit may include an engine in which operating conditions suitable for active regeneration of the PF may be obtained, suitable for vehicles that rarely operate at an engine power that results is sufficient temperatures for passive PF regeneration. Another technical benefit may include reduced cold start emissions thanks to that optimal temperature conditions for NOx reduction within the SCR unit of the aftertreatment system may be reached relatively fast.

[0019]

[0015] Optionally in some examples, including in at least one preferred example, the engine further comprises a cooler arranged to cool the exhaust gases recirculated from the first group of engine cylinders. Cooling of the recirculated exhaust gases may be advantageous during normal operation of the engine.

[0016] Optionally in some examples, including in at least one preferred example, the second exhaust manifold portion is fluidly connectable to the inlet manifold via a second valve to enable recirculation of hot exhaust gases from the second group of engine cylinders. The recirculation of hot exhaust gases may contribute to a quick heating of the engine and of the EATS during cold starts.

[0020]

[0017] According to a third aspect of the disclosure, a vehicle comprising the internal combustion engine of the second aspect is provided.

[0021]

[0018] Optionally in some examples, including in at least one preferred example, the vehicle may be a heavy-duty vehicle such as a bus, a truck, or a working machine.

[0022]

[0019] According to a fourth aspect of the disclosure, a computer-implemented method for controlling an internal combustion engine is provided. The internal combustion engine comprises: a first and a second group of engine cylinders, an inlet manifold, an exhaust manifold comprising a first exhaust manifold portion fluidly connected to the first group of engine cylinders and a second exhaust manifold portion fluidly connected to the second group of engine cylinders, the first exhaust manifold portion being fluidly connectable to the inlet manifold via a first valve to enable recirculation of exhaust gases from the first group of engine cylinders, an exhaust aftertreatment system fluidly connected to the exhaust manifold via a pressure regulating device, a fuel injection system configured to inject fuel into the first and second groups of engine cylinders, the method comprising: controlling, by processing circuitry of a computer system, the first valve to a closed valve position, and controlling, by the processing circuitry, the pressure regulating device to create a back pressure within the exhaust manifold, and controlling, by the processing circuitry, the fuel injection system to inject fuel into the first and second groups of engine cylinders such that combustion is phased earlier in one of the groups of engine cylinders than in the other group of engine cylinders.

[0020] Advantages and technical benefits of the method according to the fourth aspect largely correspond to those of the computer system according to the first aspect.

[0023]

[0021] Optionally in some examples, including in at least one preferred example, the controlling of the fuel injection system comprises controlling it to inject the fuel such that combustion is phased earlier in the first group of engine cylinders than in the second group of engine cylinders.

[0024]

[0022] Optionally in some examples, including in at least one preferred example, the controlling of the fuel injection system further comprises controlling it to inject a smaller amount of fuel into the first group of engine cylinders than into the second group of engine cylinders.

[0025]

[0023] Optionally in some examples, including in at least one preferred example, the controlling of the fuel injection system further comprises controlling it to inject fuel into the first group of engine cylinders with a fuel injection timing resulting in at least 50 percent of the fuel injected to each engine cylinder being burnt before a top dead centre of the respective engine cylinder.

[0026]

[0024] Optionally in some examples, including in at least one preferred example, the controlling of the fuel injection system comprises controlling it to inject fuel into the first group of engine cylinders with a fuel injection timing selected to achieve an engine braking effect.

[0027]

[0025] Optionally in some examples, including in at least one preferred example, the method further comprises detecting, by the processing circuitry, that a regeneration condition applies, and in response thereto initiating regeneration of a particulate filter of the exhaust aftertreatment system by performing said control of the first valve, the pressure regulating device, and the fuel injection system.

[0028]

[0026] Optionally in some examples, including in at least one preferred example, the method further comprises detecting, by the processing circuitry, that a cold start condition applies, and in response thereto initiating warming of the exhaust aftertreatment system by performing said control of the first valve, the pressure regulating device, and the fuel injection system.

[0029]

[0027] Optionally in some examples, including in at least one preferred example, the method further comprises: monitoring, by the processing circuitry, a temperature within the internal combustion engine, detecting, by the processing circuitry, that a predetermined temperature criterion is met, and in response thereto controlling the first valve to an open position.

[0030]

[0028] 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.

[0031]

[0029] 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.

[0032] BRIEF DESCRIPTION OF THE DRAWINGS

[0033]

[0030] Examples are described in more detail below with reference to the appended drawings. The drawings are schematic and not drawn to scale.

[0034]

[0031] FIG. 1 is an exemplary vehicle according to an example.

[0035]

[0032] FIG. 2 schematically illustrates an internal combustion engine according to a first example.

[0036]

[0033] FIG. 3 is a flow chart of an exemplary method according to an example.

[0037]

[0034] FIG. 4 schematically illustrates an internal combustion engine according to a second example.

[0038]

[0035] FIG. 5 is a flow chart of an exemplary method according to another example.

[0039]

[0036] FIG. 6 is a schematic diagram of an exemplary computer system for implementing examples disclosed herein, according to an example.

[0040] DETAILED DESCRIPTION

[0041]

[0037] 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.

[0042]

[0038] A heavy-duty vehicle 1 in the form of a towing truck is schematically illustrated in FIG. 1. The vehicle 1 is driven by an internal combustion engine 2, such as a diesel engine, configured to provide propulsion power to drive one or more pairs of driven wheels. To reduce emissions in the exhaust gases from the engine 2, an exhaust aftertreatment system (EATS) 5 including at least a selective catalytic reduction (SCR) unit and a particulate filter (PF) is provided. The EATS 5 may also comprise other aftertreatment units such as an oxidation catalyst unit (DOC) and a pre-SCR unit. The SCR unit is configured to reduce emissions of nitrogen oxides (NOx) by using a reductant comprising ammonia, NH3. Urea may typically be used as the reductant. For the SCR unit to function optimally and to maintain NOx emissions at an acceptable level, a temperature of the EATS 5 must be kept within optimal boundaries during operation of the vehicle 1. If the EATS temperature is too low or too high, the SCR unit is unable to convert the NOx optimally, which may result in NOx spikes in the emissions from the vehicle 1. Furthermore, at too low temperatures, urea deposits may form in the SCR unit, leading to an increased pressure drop over the SCR unit that may increase emissions as well as fuel consumption. Therefore, in connection with starting of the engine 2, it is important to quickly bring the EATS 5 to the temperature range at which the SCR unit functions optimally and thereby reduce cold start emissions.

[0043]

[0039] Another situation in which it is desirable to increase the temperature within the EATS 5 is when active regeneration of the PF is needed. In such an active regeneration event, soot particles in the PF are burnt in a controlled process when the vehicle 1 is parked. For efficient active regeneration, it is further desirable that the exhaust gases from the engine 2 comprises relatively large amounts of NOx.

[0044]

[0040] The present disclosure provides methods and means for actively controlling the engine 2 such that the temperature of the EATS 5 may be increased to the desired temperature ranges during, for example, cold starts and active regeneration events. For this purpose, a computer system 600 comprising processing circuitry configured to control the engine 2 is provided. Although the computer system 600 is in FIG. 1 illustrated as located onboard the vehicle 1, at least a part of the computer system, such as comprising the processing circuitry, may in other embodiments be located remote from the vehicle, such as on a cloud or server and configured to communicate with an on-board control unit. The computer system 600 may e.g. comprise an electronic engine control unit of the vehicle 1.

[0045]

[0041] FIG. 2 illustrates an internal combustion engine 2 according to a first example, herein also referred to as an engine 2, that may be used in a vehicle 1 such as the one illustrated in FIG. 1, and that may be controlled by the computer system 600. The engine 2 may be configured for combustion of fuel such as diesel, biofuel, hydrogen, methane, etc. The engine 2 comprises an inlet manifold 3 via which air and recirculated exhaust gases are provided to a first group of engine cylinders 10 and a second group of engine cylinders 20. In the illustrated first example, each group comprises three engine cylinders, although in other examples, a different number of engine cylinders may be provided in each group. Preferably, the first and second groups 10, 20 comprise the same number of engine cylinders. A fuel injection system 7, configured to inject fuel into the first and second groups of engine cylinders 10, 20, is further provided.

[0046]

[0042] Exhaust gases from the first and second groups of engine cylinders 10, 20 are directed to an exhaust manifold 4 comprising a first exhaust manifold portion 14, fluidly connected to the first group of engine cylinders 10, and a second exhaust manifold portion 24, fluidly connected to the second group of engine cylinders 20.

[0047]

[0043] The EATS 5, herein comprising a DOC unit, an SCR unit and a PF unit, is fluidly connected to the exhaust manifold 4 via a pressure regulating device 6. The first and second exhaust manifold portions 14, 24 are fluidly separated from one another. They are both fluidly connected to the EATS 5 via the pressure regulating device 6, wherein the pressure regulating device 6 may include a turbocharger. The pressure regulating device 6 may, e.g., comprise a twin entry variable geometry turbocharger. It regulates the pressure within the exhaust manifold 4. By closing the turbocharger, the pressure within the exhaust manifold 4, including both the first and the second exhaust manifold portions 14, 24, is increased.

[0048]

[0044] The first exhaust manifold portion 14 is fluidly connectable to the inlet manifold 3 via a first valve 15 provided in an exhaust gas recirculation conduit 16 to enable recirculation of exhaust gases from the first group of engine cylinders 10. A cooler 8 is arranged in the exhaust gas recirculation conduit 16 to cool the exhaust gases recirculated from the first group of engine cylinders 10 during normal operation of the vehicle 1. The first valve 15 may typically be a butterfly valve, which results in a low pressure drop during normal operation of the vehicle 1 and hence efficient recirculation of exhaust gases from the first group of engine cylinders 10. In the illustrated first example, no corresponding valve is provided for recirculation of exhaust gases from the second group of engine cylinders 24. Thus, all exhaust gases from the second group of engine cylinders 20 are led via the pressure regulating device 6 to the EATS 5.

[0045] The computer system 600 comprises processing circuitry configured to control at least the fuel injection system 7, the pressure regulating device 6 and the first valve 15 as indicated by the dotted lines in FIG. 2. In a temperature increasing operation, the processing circuitry is configured to control the engine 2 using a method schematically illustrated in FIG. 3. According to the proposed method, the processing circuitry is in an action SI configured to control the first valve 15 to a closed valve position and in an action S2 configured to control the pressure regulating device 6 to create a back pressure within the exhaust manifold 4. It is further, in an action S3, configured to control the fuel injection system 7 to inject fuel into the first and second groups of engine cylinders 10, 20 such that combustion is phased earlier in one of the groups of engine cylinders 10, 20 than in the other group of engine cylinders 10, 20. In the first example illustrated in FIG. 2, the processing circuitry is configured to control the fuel injection system 7 to inject the fuel such that combustion is phased earlier in the first group of engine cylinders 10 than in the second group of engine cylinders 20. This is particularly useful for PF regeneration and may also be applicable for warming of the engine 2 at cold start.

[0049]

[0046] The back pressure created within the exhaust manifold 4 by the pressure regulating device 6 will generally increase the temperature of the exhaust gases. The hot exhaust gases in the second exhaust manifold portion 24 will always be forced to leave the exhaust manifold 4 via the pressure regulating device 6 and the EATS 5. With the first valve 15 closed, exhaust gases in the first exhaust manifold portion 14 will also be forced to leave the exhaust manifold 4 via the EATS 5. However, when the first valve 15 is not entirely gas proof, which is typically the case for a butterfly valve, the back pressure may lead to leakage of exhaust gases from the first manifold portion 14 via the first valve 15. The leaked exhaust gases are recirculated to the inlet manifold 3. This recirculation may reduce the engine temperature and prevent it from reaching a level suitable for active regeneration of the PF. The leakage of recirculation exhaust gas to the engine 2 will also lead to reduced engine out NOx emissions and by this reducing the amount of NO2 created during combustion and in the DOC unit, and by this it will also increase the active soot regeneration time. Hence, if a regeneration of the PF is to be carried out, the recirculation must be minimized. According to the present disclosure, this is achieved by reducing the pressure in at least the first exhaust manifold portion 14 by early injection of fuel into the first group of engine cylinders 10. The reduced pressure will lead to a reduced risk of leakage via the first valve 15. At the same time, the different timings of fuel injection into the first and second groups of engine cylinders 10, 20 will reduce the engine efficiency and increase the engine temperature. The early fuel injection into the first group of engine cylinders 10 will furthermore increase the amount of NOx gases created during the combustion, which is advantageous for PF regeneration.

[0050]

[0047] The processing circuitry may further be configured to control the fuel injection system 7 to inject a smaller amount of fuel into the first group of engine cylinders 10 than into the second group of engine cylinders 20. For example, about 40% of the total fuel may be injected into the first group of engine cylinders 10, and about 60% of the total fuel may be injected into the second group of engine cylinders 20. By injecting less fuel into the first group of engine cylinders 10, a further pressure reduction in the first exhaust manifold portion 14 is possible, hence further reducing the risk for leakage of exhaust gases via the first valve 15. By injecting more fuel into the second group of engine cylinders 20, the temperature of the exhaust gases and the engine out NOx forced into the EATS 5 can be increased, thereby improving the conditions for PF regeneration.

[0051]

[0048] During an active PF regeneration event, the processing circuitry may be configured to control the fuel injection system 7 to inject fuel into the first group of engine cylinders 10 with a fuel injection timing of a main fuel injection resulting in at least 50 % of the fuel injected to each engine cylinder 10 being burnt before a top dead centre (TDC) of the respective engine cylinder 10. For example, the processing circuitry may be configured to control the fuel injection system 7 to inject fuel into the first group of engine cylinders 10 with a fuel injection timing selected to achieve an engine braking effect. Merely by way of example, for an internal combustion engine operating at 1400 rpm in a parked vehicle, the main fuel injection into the first group of engine cylinders 10 may be started at about 9 crank angle degrees (CAD) before TDC or earlier, creating a braking effect. The additional braking effect will increase the engine temperature and the engine out NOx, and hence the temperature of the EATS 5 and the NOx fed to the EATS 5, without increasing a rotational speed of the engine 2. If no braking effect is desired, the main fuel injection into the first group of engine cylinders 10 may be started later than when a braking effect is desired, such as at less than 9 CAD before TDC, e.g., at 6-8 CAD before TDC.

[0052]

[0049] The processing circuitry may be configured to detect that a regeneration condition applies, and in response thereto initiate active regeneration of the PF by performing said control of the first valve 15, the pressure regulating device 6, and the fuel injection system 7. The vehicle 1 should be stationary during the active regeneration event. The processing circuitry may be configured to detect that the regeneration condition applies when a driver requests regeneration using a user interface, such as by pushing a button or by selecting the appropriate item from a menu presented on a touchscreen or similar. The need for regeneration of the PF may be detected based on sensor data relating to a differential pressure over the PF. The processing circuitry may determine that regeneration is needed based on sensor data, inform the driver accordingly via a user interface, and initiate the regeneration in response to the subsequent driver request.

[0053]

[0050] As previously mentioned, the proposed method may also be used to heat the engine 2 during cold starts to quickly achieve a suitable operating temperature for the SCR unit of the EATS 5. Hence, the processing circuitry may be configured to detect that a cold start condition applies, e.g., based on temperature data from a temperature sensor (not shown), and in response thereto initiate warming of the EATS 5 by performing the actions illustrated in FIG. 3. In this case, the processing circuitry may further be configured to monitor a temperature within the internal combustion engine 2, such as the temperature of the exhaust gases, or of a coolant used to cool the recirculated exhaust gases within the cooler 8, or within the EATS 5. Once the processing circuitry detects that a predetermined temperature criterion is met, it controls the first valve 15 to an open position, hence allowing recirculation of exhaust gases. The temperature criterion may typically be considered met when a temperature threshold is reached. The temperature threshold may be a temperature value corresponding to, or being close to, a dew point of the exhaust gases. However, the threshold may in some examples be set to a temperature below the dew point.

[0054]

[0051] An internal combustion engine 2’ according to a second example is schematically illustrated in FIG. 4. The engine 2’ according to the second example only differs from the engine 2 according to the first example illustrated in FIG. 2 in that a second valve 25 is provided for recirculation of exhaust gases from the second group of engine cylinders 20 to the inlet manifold 3. A conduit 26 from the second exhaust manifold portion 24 is fluidly connected to the exhaust gas recirculation conduit 16 downstream of the cooler 8, i.e., the exhaust gases recirculated from the second exhaust manifold portion 24 will be warmer than the exhaust gases recirculated from the first exhaust manifold portion 14.

[0052] In the engine 2 according to the second example, during cold start, the processing circuit may be configured to perform the following actions, illustrated in FIG. 5:

[0055]

[0053] SI 1 : Controlling the first valve 15 to a closed position and the second valve 25 to an open position.

[0056]

[0054] S12: Controlling, the pressure regulating device 6 to create a back pressure within the exhaust manifold 4.

[0057]

[0055] S13: Controlling the fuel injection system 7 to inject fuel into the first and second groups of engine cylinders 10, 20 such that combustion is phased earlier in one of the groups of engine cylinders 10, 20 than in the other group of engine cylinders 10, 20.

[0058]

[0056] By said control of the first and second valves 15, 25 and the pressure regulating device 6, hot exhaust gases from the second exhaust manifold 24 will be able to recirculate via the second valve 25, while only a small amount of exhaust gases from the first exhaust manifold portion 14 will leak to the exhaust gas recirculation conduit 16 via the first valve 15 while most of the exhaust gases from the first exhaust manifold portion 14 will be led to the EATS 5 via the pressure regulating device 6. Hence, hot exhaust gases will efficiently warm up the engine 2 such that the EATS 5 quickly reaches an optimal temperature interval for NOx conversion within the SCR unit.

[0059]

[0057] In the second example, combustion may be phased earlier in either one of the first and second groups of engine cylinders 10, 20. When combustion is phased earlier in the first group of engine cylinders 10, less than 50% of the total fuel amount may in some cases be injected into the first group of engine cylinders 10, and more than 50% into the second group of engine cylinders 20. The first group of engine cylinders 10 will hereby primarily be used for quick heating of the EATS 5, while the hot exhaust gases from the second group of engine cylinders 20 are recirculated with the purpose of minimizing NOx emissions. However, in other cases, more fuel may be injected into the group of engine cylinders in which the combustion is phased early.

[0060]

[0058] In some cases, with the engine 2’ according to the second example, the processing circuitry may be configured to control the fuel injection system 7 to inject fuel into the first and second group of cylinders 10, 20 such that combustion is similarly phased in both groups of engine cylinders 10, 20, but such that different amounts of fuel are injected. This may be sufficient for reaching a desired temperature for NOx reduction within the SCR unit of the EATS 5 during cold start of the engine 2’.

[0059] The processing circuitry may in the second example further be configured to monitor a temperature within the internal combustion engine 2as previously described. Once the processing circuitry detects that a predetermined temperature criterion is met, it controls the first valve 15 to an open position, hence allowing recirculation of exhaust gases via the cooler 8. At the same time, it controls the second valve 25 to a closed position, while continuing to control the pressure regulating device 6 to create a back pressure. The temperature criterion may typically be considered met when a temperature threshold is reached. The temperature threshold may be a temperature value corresponding to, or being close to, a dew point of the exhaust gases. However, the threshold may in some examples be set to a temperature below the dew point.

[0061]

[0060] The methods and means described herein may in some examples be used together with an electric heater (not shown) arranged to heat the EATS 5 during cold starts and / or active PF regeneration events. In other examples, the methods and means may be used without any electric heater.

[0062]

[0061] FIG. 6 is a schematic diagram of a computer system 600 for implementing examples disclosed herein. The computer system 600 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 600 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 600 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.

[0063]

[0062] The computer system 600 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 600 may include processing circuitry 602 (e.g., processing circuitry including one or more processor devices or control units), a memory 604, and a system bus 606. The computer system 600 may include at least one computing device having the processing circuitry 602. The system bus 606 provides an interface for system components including, but not limited to, the memory 604 and the processing circuitry 602. The processing circuitry 602 may include any number of hardware components for conducting data or signal processing or for executing computer code stored in memory 604. The processing circuitry 602 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 602 may further include computer executable code that controls operation of the programmable device.

[0064]

[0063] The system bus 606 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 604 may be one or more devices for storing data and / or computer code for completing or facilitating methods described herein. The memory 604 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 604 may be communicably connected to the processing circuitry 602 (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 604 may include non-volatile memory 608 (e.g., read-only memory (ROM), erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), etc.), and volatile memory 610 (e.g., randomaccess 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 602. A basic input / output system (BIOS) 612 may be stored in the non-volatile memory 608 and can include the basic routines that help to transfer information between elements within the computer system 600.

[0065]

[0064] The computer system 600 may further include or be coupled to a non-transitory computer-readable storage medium such as the storage device 614, 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 614 and other drives associated with computer-readable media and computer-usable media may provide nonvolatile storage of data, data structures, computer-executable instructions, and the like.

[0066]

[0065] 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 614 and / or in the volatile memory 610, which may include an operating system 616 and / or one or more program modules 618. All or a portion of the examples disclosed herein may be implemented as a computer program 620 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 614, which includes complex programming instructions (e.g., complex computer-readable program code) to cause the processing circuitry 602 to carry out actions described herein. Thus, the computer-readable program code of the computer program 620 can comprise software instructions for implementing the functionality of the examples described herein when executed by the processing circuitry 602. In some examples, the storage device 614 may be a computer program product (e.g., readable storage medium) storing the computer program 620 thereon, where at least a portion of a computer program 620 may be loadable (e.g., into a processor) for implementing the functionality of the examples described herein when executed by the processing circuitry 602. The processing circuitry 602 may serve as a controller or control system for the computer system 600 that is to implement the functionality described herein.

[0066] The computer system 600 may include an input device interface 622 configured to receive input and selections to be communicated to the computer system 600 when executing instructions, such as from a keyboard, mouse, touch-sensitive surface, etc. Such input devices may be connected to the processing circuitry 602 through the input device interface 622 coupled to the system bus 606 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 600 may include an output device interface 624 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 600 may include a communications interface 626 suitable for communicating with a network as appropriate or desired.

[0067]

[0067] 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.

[0068]

[0068] 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.

[0069]

[0069] 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.

[0070] 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.

[0070]

[0071] 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.

[0071]

[0072] 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.

Claims

ClaimsWhat is claimed is:

1. A computer system (600) comprising processing circuitry (602) configured to control an internal combustion engine (2), the internal combustion engine (2) comprising: a first and a second group of engine cylinders (10, 20), an inlet manifold (3), an exhaust manifold (4) comprising a first exhaust manifold portion (14) fluidly connected to the first group of engine cylinders (10) and a second exhaust manifold portion (24) fluidly connected to the second group of engine cylinders (20), the first exhaust manifold portion (14) being fluidly connectable to the inlet manifold (3) via a first valve (15) to enable recirculation of exhaust gases from the first group of engine cylinders (10), an exhaust aftertreatment system (5) fluidly connected to the exhaust manifold (4) via a pressure regulating device (6), a fuel injection system (7) configured to inject fuel into the first and second groups of engine cylinders (10, 20), the processing circuitry being configured to: control the first valve (15) to a closed valve position, control the pressure regulating device (6) to create a back pressure within the exhaust manifold (4), and control the fuel injection system (7) to inject fuel into the first and second groups of engine cylinders (10, 20) such that combustion is phased earlier in one of the groups of engine cylinders (10, 20) than in the other group of engine cylinders (10, 20).

2. The computer system of claim 1, wherein the processing circuitry is configured to control the fuel injection system (7) to inject the fuel such that combustion is phased earlier in the first group of engine cylinders (10) than in the second group of engine cylinders (20).

3. The computer system of claim 2, wherein the processing circuitry is further configured to control the fuel injection system (7) to inject a smaller amount of fuel into the first group of engine cylinders (10) than into the second group of engine cylinders (20).

4. The computer system of any of claims 2-3, wherein the processing circuitry is configured to control the fuel injection system (7) to inject fuel into the first group of engine cylinders (10) with a fuel injection timing resulting in at least 50 percent of the fuel injected to each engine cylinder (10) being burnt before a top dead centre of the respective engine cylinder (10).

5. The computer system of any of claims 2-4, wherein the processing circuitry is configured to control the fuel injection system (7) to inject fuel into the first group of engine cylinders (10) with a fuel injection timing selected to achieve an engine braking effect.

6. The computer system of any of claims 2-4, wherein the processing circuitry is further configured to detect that a regeneration condition applies, and in response thereto initiate regeneration of a particulate filter (PF) of the exhaust aftertreatment system (5) by performing said control of the first valve (15), the pressure regulating device (6), and the fuel injection system (7).

7. The computer system of any of claims 1-5, wherein the processing circuitry is further configured to detect that a cold start condition applies, and in response thereto initiate warming of the exhaust aftertreatment system (5) by performing said control of the first valve (15), the pressure regulating device (6), and the fuel injection system (7).

8. The computer system of claim 7, wherein the processing circuitry is further configured to: monitor a temperature within the internal combustion engine (2), detect that a predetermined temperature criterion is met, and in response thereto control the first valve (15) to an open position.

9. An internal combustion engine (2) comprising: a first and a second group of engine cylinders (10, 20), an inlet manifold (3), an exhaust manifold (4) comprising a first exhaust manifold portion (14) fluidly connected to the first group of engine cylinders (10) and a second exhaust manifold portion(24) fluidly connected to the second group of engine cylinders (20), the first exhaust manifold portion (14) being fluidly connectable to the inlet manifold (3) via a first valve (15) to enable recirculation of exhaust gases from the first group of engine cylinders (10), an exhaust aftertreatment system (5) fluidly connected to the exhaust manifold (4) via a pressure regulating device (6), a fuel injection system (7) configured to inject fuel into the first and second groups of engine cylinders (10, 20), and a computer system (600) of any one of the preceding claims.

10. The internal combustion engine of claim 9, further comprising a cooler (8) arranged to cool the exhaust gases recirculated from the first group of engine cylinders (10).

11. The internal combustion engine of claim 10, wherein the second exhaust manifold portion (24) is fluidly connectable to the inlet manifold (3) via a second valve (25) to enable recirculation of hot exhaust gases from the second group of engine cylinders (20).

12. A vehicle (1) comprising the internal combustion engine (2) of any of claims 9-11.

13. A computer-implemented method for controlling an internal combustion engine (2), the internal combustion engine (2) comprising: a first and a second group of engine cylinders (10, 20), an inlet manifold (3), an exhaust manifold (4) comprising a first exhaust manifold portion (14) fluidly connected to the first group of engine cylinders (10) and a second exhaust manifold portion (24) fluidly connected to the second group of engine cylinders (20), the first exhaust manifold portion (14) being fluidly connectable to the inlet manifold (3) via a first valve (15) to enable recirculation of exhaust gases from the first group of engine cylinders (10), an exhaust aftertreatment system (5) fluidly connected to the exhaust manifold (4) via a pressure regulating device (6), a fuel injection system (7) configured to inject fuel into the first and second groups of engine cylinders (10, 20), the method comprising:controlling (SI), by processing circuitry (602) of a computer system (600), the first valve (15) to a closed valve position, controlling (S2), by the processing circuitry (602), the pressure regulating device (6) to create a back pressure within the exhaust manifold (4), and controlling (S3), by the processing circuitry (602), the fuel injection system (7) to inject fuel into the first and second groups of engine cylinders (10, 20) such that combustion is phased earlier in one of the groups of engine cylinders (10, 20) than in the other group of engine cylinders (10, 20).

14. The method of claim 13, wherein the controlling of the fuel injection system (7) comprises controlling it to inject the fuel such that combustion is phased earlier in the first group of engine cylinders (10) than in the second group of engine cylinders (20).

15. The method of claim 14, wherein the controlling of the fuel injection system (7) further comprises controlling it to inject a smaller amount of fuel into the first group of engine cylinders (20) than into the second group of engine cylinders (10).

16. The method of any of claims 14-15, wherein the controlling of the fuel injection system (7) further comprises controlling it to inject fuel into the first group of engine cylinders (10) with a fuel injection timing resulting in at least 50 percent of the fuel injected to each engine cylinder (10) being burnt before a top dead centre of the respective engine cylinder (10).

17. The method of any of claims 14-16, wherein the controlling of the fuel injection system (7) comprises controlling it to inject fuel into the first group of engine cylinders (10) with a fuel injection timing selected to achieve an engine braking effect.

18. The method of any of claims 14-17, further comprising detecting, by the processing circuitry, that a regeneration condition applies, and in response thereto initiating regeneration of a particulate filter of the exhaust aftertreatment system by performing said control of the first valve (15), the pressure regulating device (6), and the fuel injection system (7).

19. The method of any of claims 13-18, further comprising detecting, by the processing circuitry, that a cold start condition applies, and in response thereto initiating warming of the exhaust aftertreatment system (5) by performing said control of the first valve (15), the pressure regulating device (6), and the fuel injection system (7).

20. The method of claim 19, further comprising: monitoring, by the processing circuitry, a temperature within the internal combustion engine (2), detecting, by the processing circuitry, that a predetermined temperature criterion is met, and in response thereto controlling the first valve (15) to an open position.

21. A computer program product comprising program code for performing, when executed by the processing circuitry (602), the method of any of claims 13-20.

22. A non-transitory computer-readable storage medium comprising instructions, which when executed by the processing circuitry, cause the processing circuitry (602) to perform the method of any of claims 13-20.

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