Method of operating an internal combustion engine, computer program, computer readable medium, control device, and vehicle

Abstract

A method (100) of operating an internal combustion engine (1) of a vehicle (2) is disclosed, wherein the engine (1) comprises one or more combustion chambers (4) and a component (41) configured to limit an airflow to the one or more combustion chambers (4) during a motoring phase of the engine (1). The method (100) comprises the step of determining (104), based on at least one of a current weight estimate (wE) of the vehicle (2) and a current overall transmission ratio (tr) between the engine (1) and drive wheels (27) of the vehicle (2), whether to operate the engine (1) in a fuel cut allowance mode (AM) or in a fuel cut limitation mode (LM) during the motoring phase of the engine (1). The present disclosure also relates to a computer program, a computer readable medium, a control device (21) and a vehicle (2).

Description

Technical Field

[0001] This disclosure relates to a method of operating an internal combustion engine of a vehicle. This disclosure also relates to a computer program, a computer-readable medium, a control device configured to control the operation of an internal combustion engine of a vehicle, and a vehicle including the control device. Background Technology

[0002] An internal combustion engine is used to power a vehicle, typically via its drivetrain and drive wheels. In many vehicles, the drivetrain includes a transmission that can be controlled between at least two different gears to provide at least two different gear ratios between the engine and the vehicle's drive wheels.

[0003] An internal combustion engine, such as a four-stroke internal combustion engine, includes one or more cylinders and a piston arranged in each cylinder. The piston is connected to the engine's crankshaft via a corresponding connecting rod and typically includes one or more piston rings to seal the area between the piston and the cylinder. The piston is arranged to reciprocate within the cylinder as the crankshaft rotates. The crankshaft is typically housed in the engine's crankcase, which includes crankshaft bearings lubricated to the crankshaft, bearings between the piston rod and the crankshaft, bearings between the piston and the cylinder, and the area between the cylinder and the piston.

[0004] An engine typically also includes one or more intake valves and one or more exhaust valves, as well as one or more fuel supply devices. The intake and exhaust valves are controlled by corresponding valve control devices, which typically include one or more camshafts rotatably connected to the engine's crankshaft via belts, chains, gears, pushrods, etc. A four-stroke internal combustion engine completes four individual strokes in two crankshaft revolutions. A stroke refers to the complete travel of the piston along the cylinder in any direction. The uppermost position of the piston in the cylinder is usually called top dead center (TDC), and the lowermost position is usually called bottom dead center (BDC).

[0005] The strokes are completed in the following order: intake stroke, compression stroke, expansion stroke, and exhaust stroke. During the operation of a conventional four-stroke internal combustion engine, the intake valve control device keeps the intake valves open during the piston's intake stroke to allow air or an air-fuel mixture to enter the cylinder. During the compression stroke, all valves should be closed to allow compression of the air or air-fuel mixture in the cylinder. If the engine is in a power-generating state, the fuel in the cylinder is typically ignited by the ignition device near the end of the compression stroke. The combustion of fuel in the cylinder significantly increases the pressure and temperature within the cylinder. Combustion typically continues for most of the subsequent expansion stroke. The increased pressure and temperature in the cylinder gained through combustion are partially converted into mechanical work supplied to the crankshaft during the expansion stroke.

[0006] Obviously, during the expansion stroke, all valves should remain closed to allow the increased pressure and temperature to be converted into mechanical work. Because most combustion typically occurs during the expansion stroke, it is often also called the combustion stroke. In the subsequent exhaust stroke, the exhaust valve control unit opens the cylinder's exhaust valve to allow exhaust gases to escape from the cylinder into the exhaust system. The exhaust stroke is then followed by the intake stroke.

[0007] A common concern when designing internal combustion engines is their emissions levels and fuel consumption. Due to environmental concerns, almost all vehicles currently sold include some form of exhaust aftertreatment system. Examples include catalytic converters, particulate filters, and selective catalytic reduction (SCR) devices.

[0008] The conversion efficiency of these exhaust aftertreatment systems is highly dependent on the high temperature of the exhaust gases. Therefore, the conversion efficiency of exhaust aftertreatment systems may be problematic during the engine's motoring phase.

[0009] The term "drag phase" refers to a scenario where the engine crankshaft rotates under external torque. This external torque may originate from, for example, the vehicle's inertia during downhill coasting or when the vehicle is decelerating (where the vehicle is in gear and the engine clutch is engaged). Typically, no fuel is supplied to the combustion chamber during the drag phase. Pumped air through the engine's combustion chamber and frictional losses within the engine generate a negative crankshaft torque, which in turn generates braking torque at the vehicle's drive wheels via the vehicle's drivetrain.

[0010] Many internal combustion engines include components configured to restrict airflow to one or more combustion chambers during the engine's drag phase. Airflow to one or more combustion chambers can be restricted, for example, during the engine's drag phase to suppress temperature drops in the exhaust aftertreatment system during this phase. Such components may include, for example, a throttle valve and / or a camshaft phasing assembly, the throttle valve being controllable to restrict airflow to one or more combustion chambers, and the camshaft phasing assembly being configured to phase-shift control of the engine's intake and / or exhaust valves to restrict airflow to one or more combustion chambers.

[0011] Another problem that can arise during the drag phase is insufficient pressure in the combustion chamber due to restricted airflow. Insufficient pressure can cause lubricant to be delivered to the combustion chamber via the piston rings. When combustion is subsequently initiated, this lubricant is burned off, resulting in particulate emissions from the engine. Particulate emissions from the engine can be classified in two different ways (by particulate mass and particulate number, abbreviated as PM and PN, respectively). Particulate emissions primarily consist of soot / smoke. Additionally, the delivery of lubricant via the piston rings to the engine's combustion chamber increases lubricant consumption.

[0012] One way to reduce lubricant delivery across the piston rings to the combustion chamber during the drag phase is to add fuel to the combustion chamber during this phase. The combustion of the added fuel increases the pressure in the combustion chamber, thereby reversing the pressure balance across the piston rings and reducing lubricant delivery to the combustion chamber.

[0013] However, adding fuel to the combustion chamber can generate positive crankshaft torque, which can reduce braking torque at the vehicle's drive wheels, or even generate positive thrust torque at the drive wheels. This reduction in braking torque and the generation of thrust torque can be felt by the vehicle's driver and may reduce the vehicle's driving experience and drivability. Similarly, this reduction in braking torque or the generation of thrust torque may cause control problems for at least partially autonomous driving systems. That is, if the driver or at least partially autonomous driving systems request the vehicle to decelerate, adding fuel to the combustion chamber will reduce the rate of deceleration, i.e., its rate of deceleration.

[0014] When a driver requests deceleration by releasing the accelerator pedal, the rate of deceleration may be unexpected and give the impression that the vehicle is unresponsive and / or not slowing down as quickly as expected. Furthermore, in such situations, the driver may need to apply the wheel brakes for better deceleration. Similarly, if at least partially autonomous driving systems initiate deceleration, fuel injection into the combustion chamber may force the system to utilize other means of slowing the vehicle, such as the wheel brakes.

[0015] Furthermore, adding fuel to the combustion chamber during the dragging phase can cause drivetrain vibrations. Drivetrain vibrations can lead to jerking during vehicle operation, significantly reducing the driving experience. This jerking not only makes the ride uncomfortable for vehicle occupants but can also interfere with the ability to smoothly control the vehicle, affecting safety and handling.

[0016] Another way to address the issue of lubricant delivery to the combustion chamber during the back-end phase is to implement new hardware solutions or to redesign and / or structurally modify individual engine components, such as the piston ring assembly. However, such solutions typically require extensive testing and evaluation processes, which increases the cost of the final product, and is generally advantageous if the product (such as a combustion engine or vehicle) has conditions and / or characteristics suitable for cost-effective production. Summary of the Invention

[0017] The object of this invention is to overcome or at least mitigate at least some of the problems and disadvantages described above. This object is achieved through the subject matter of the appended independent claims.

[0018] According to a first aspect of this disclosure, the objective is achieved by a method of operating an internal combustion engine of a vehicle, wherein the engine is configured to power the vehicle via the vehicle's drive wheels, and wherein the engine includes one or more combustion chambers and components configured to restrict airflow to the one or more combustion chambers during a reversing phase of the engine. The method includes the following steps: - Based on at least one of the current weight estimate of the vehicle and the current total gear ratio between the engine and the drive wheels of the vehicle, determine whether the engine is operated in a fuel cut-off permitted mode or a fuel cut-off restricted mode during the engine's dragging phase.

[0019] Therefore, a method is provided that can reduce lubricant delivery to the engine's combustion chamber while avoiding a significant reduction in vehicle drivability, handling smoothness, and driving experience. This is because, as the inventors of this disclosure recognize, each of the vehicle's current weight and current overall gear ratio has a significant impact on the negative effects of engine operation in fuel cut-off limiting mode on vehicle drivability, handling smoothness, and driving experience. Such negative effects may include, for example, an undesirable and / or unexpected reduction in vehicle deceleration rate, drivetrain oscillations, jerking, and impaired vehicle drivability.

[0020] Therefore, by determining whether the engine is operated in a fuel cut-off permitted mode or a fuel cut-off restricted mode during the engine's drag phase based on at least one of the vehicle's current weight estimate and the current total gear ratio between the engine and the vehicle's drive wheels, a method is provided that can effectively reduce the delivery of lubricant to the engine's combustion chamber while ensuring drivability, smooth operation, and overall driving experience.

[0021] As another result, a method is provided that can reduce particulate emissions and excessive lubricant consumption from the engine, while ensuring drivability, smooth operation, and overall driving experience.

[0022] In addition, a cost-effective method is provided because it avoids the need to implement new hardware solutions and redesign and restructure individual engine components in order to reduce the delivery of lubricant to the engine's combustion chamber while ensuring vehicle drivability, handling smoothness and overall driving experience.

[0023] Therefore, a method is provided that overcomes or at least mitigates some of the problems and disadvantages mentioned above. Thus, the aforementioned objective is achieved.

[0024] As mentioned in this article, a fuel cut-off permission mode can be an operating mode that allows fuel cut-off (i.e., stopping the supply of fuel to one or more combustion chambers of an internal combustion engine).

[0025] Similarly, as mentioned in this article, a fuel cut-off limiting mode can be an operating mode for limiting fuel cut-off (i.e., stopping the supply of fuel to one or more combustion chambers of an internal combustion engine).

[0026] Optionally, the method includes the following steps: - Set parameters based on the current weight estimate and the current overall gear ratio. - If this parameter is equal to or below the threshold, the engine operates in a fuel cut-off permitted mode during the dragging phase, and - If this parameter is higher than the threshold, the engine will operate in fuel cut-off mode during the engine's drag phase.

[0027] This provides a method that can effectively reduce lubricant delivery to the engine's combustion chamber while further ensuring drivability, smooth operation, and overall driving experience. This is because the parameters are set based on the current weight estimate and the current overall gear ratio, and because the choice between operating the engine in fuel cut-off permitted mode or fuel cut-off restricted mode is based on the value of the parameters.

[0028] Optionally, the steps for setting parameters include the following: - Set parameters based on the ratio between the current weight estimate and the current total gear ratio.

[0029] Therefore, a method is provided that can effectively reduce the delivery of lubricant to the engine's combustion chamber while further ensuring drivability, handling smoothness, and overall driving experience. This is because, as the inventors of this disclosure recognize, the ratio between the current weight estimate and the current total gear ratio has a significant impact on the negative effects of engine operation in fuel cut-off limiting mode on vehicle drivability, handling smoothness, and driving experience.

[0030] More specifically, as the inventors of this disclosure recognize, a smaller ratio between the current weight estimate and the current total gear ratio generally results in a greater negative impact on engine operation in fuel cut-off limiting mode compared to a larger ratio between the current weight estimate and the current total gear ratio, and vice versa.

[0031] Therefore, by setting parameters based on the ratio between the current weight estimate and the current total gear ratio, a method is provided that can effectively reduce the delivery of lubricant to the engine's combustion chamber, while further ensuring drivability, smooth operation, and overall driving experience.

[0032] Optionally, the method includes the following steps during operation in a fuel cut-off permitted mode: - During non-restricted time periods, it is permissible to stop the supply of fuel to one or more combustion chambers.

[0033] Thus, for example, in the case of a low estimated current weight of the vehicle and / or a high current overall gear ratio between the engine and the vehicle's drive wheels, drivability, handling smoothness, and overall driving experience can be maintained. Furthermore, for example, in the case of a low estimated current weight of the vehicle and / or a high current overall gear ratio between the engine and the vehicle's drive wheels, low fuel consumption of the internal combustion engine can be ensured.

[0034] Optionally, the method includes the following steps: - Set the duration of the fuel cut-off period, and during operation in the fuel cut-off limiting mode: - Stop fuel supply to the one or more combustion chambers during the fuel cut-off period, and - After the fuel cut-off period, fuel supply to the one or more combustion chambers is initiated.

[0035] This further ensures effective prevention of lubricant delivery to the engine's combustion chamber. This is because the method includes the step of initiating fuel supply to one or more combustion chambers after a fuel cut-off period during operation in a fuel cut-off restricted mode. Furthermore, by stopping fuel supply to one or more combustion chambers during the fuel cut-off period, relatively low fuel consumption of the internal combustion engine can be ensured.

[0036] Optionally, the step of setting the duration of the fuel cut-off period includes the following steps: - Set the duration of the fuel cut-off period based on the engine's current speed.

[0037] Therefore, an adaptive method is provided that can effectively prevent lubricant from being delivered into the combustion chamber of an engine.

[0038] Optionally, the step of setting the duration of the fuel cut-off period includes the following steps: - The duration increases with increasing rotational speed; and - The duration decreases as the rotational speed decreases.

[0039] Therefore, an adaptive method is provided that can effectively prevent lubricant delivery to the engine's combustion chamber and minimize particulate emissions, while ensuring drivability, smooth operation, and overall driving experience. This is because, as the inventors of this disclosure recognize, fuel supply to one or more combustion chambers at lower engine speeds has a greater impact on the formation of particulate emissions from the engine compared to higher engine speeds.

[0040] Optionally, the step of setting the duration of the fuel cut-off period includes the following steps: - Set the duration of the fuel cut-off period based on the current total gear ratio.

[0041] Therefore, an adaptive method is provided that can reduce the delivery of lubricant to the engine's combustion chamber while avoiding a significant reduction in vehicle drivability, handling smoothness, and driving experience.

[0042] Optionally, the step of setting the duration of the fuel cut-off period includes the following steps: - Set the duration of the fuel cut-off period based on the current total gear ratio, such that the duration of the fuel cut-off period increases as the total gear ratio decreases, and decreases as the total gear ratio increases.

[0043] Therefore, an adaptive method is provided that can effectively reduce lubricant delivery to the engine's combustion chamber while providing conditions for ensuring low engine fuel consumption and maintaining drivability, smooth operation, and overall driving experience. Since the duration of the fuel cut-off period increases with the decrease in the overall gear ratio, conditions for ensuring low engine fuel consumption are provided. Lower gear ratios are typically used at relatively high vehicle speeds, such as during highway driving. As the inventors of this disclosure recognize, problems with lubricant delivery to the engine's combustion chamber and particulate emission formation are less likely to occur during such driving periods compared to when the engine is operated at a higher overall gear ratio (e.g., during city driving, vehicle start-up, etc.).

[0044] Therefore, by setting the duration of the fuel cut-off period based on the current overall gear ratio, such that the duration of the fuel cut-off period increases as the overall gear ratio decreases and decreases as the overall gear ratio increases, an adaptive method is provided that can effectively reduce the delivery of lubricant to the engine's combustion chamber, while providing conditions for maintaining low fuel consumption of the engine and ensuring drivability, smooth operation, and overall driving experience.

[0045] Optionally, the method includes the following steps: - The duration of the fuel supply period is set based on the engine's current speed. And after the step of initiating fuel supply to one or more combustion chambers: - Supply fuel to one or more combustion chambers during the fuel supply period.

[0046] This ensures that lubricant is effectively prevented from being delivered to the engine's combustion chamber during operation of the internal combustion engine in fuel cut-off mode.

[0047] Optionally, the method includes the following steps: - During the second fuel cut-off period following the fuel supply period, fuel supply to one or more combustion chambers is stopped.

[0048] Therefore, an adaptive method is provided that can effectively reduce the delivery of lubricant to the engine's combustion chamber while providing conditions for maintaining low fuel consumption in the engine.

[0049] Optionally, the method includes the following steps: - The duration of the second fuel cut-off period is set based on at least one of the engine's current speed and the current total gear ratio.

[0050] Therefore, an adaptive method is provided that can effectively reduce the delivery of lubricant to the engine's combustion chamber while ensuring drivability, smooth operation, and overall driving experience.

[0051] Optionally, the vehicle includes a transmission controllable between at least two different gears to provide at least two different gear ratios between the engine and the vehicle's drive wheels, and the method includes the following steps: - The current overall gear ratio between the engine and the vehicle's drive wheels is obtained based on the current gear engaged in the transmission.

[0052] Therefore, the current total gear ratio between the engine and the drive wheels can be obtained in a simple and efficient manner.

[0053] According to a second aspect of this disclosure, this objective is achieved by a computer program comprising instructions to cause a control device according to the second aspect of this disclosure to perform steps of a method according to some embodiments of the first aspect of this disclosure. Since the computer program includes instructions to cause the control device to perform a method according to some embodiments described herein, a computer program is provided that provides conditions for overcoming or at least mitigating at least some of the disadvantages mentioned above. Thus, the above objective is achieved.

[0054] According to a third aspect of this disclosure, this objective is achieved by a computer-readable medium storing a computer program according to a second aspect of this disclosure. Since the computer-readable medium includes instructions for causing a control device to perform methods according to some embodiments described herein, a computer-readable medium is provided that provides conditions for overcoming or at least mitigating at least some of the disadvantages mentioned above. Thus, the above objective is achieved.

[0055] According to a fourth aspect of this disclosure, the objective is achieved by a control device configured to control the operation of an internal combustion engine of a vehicle, wherein the engine is configured to provide power to the vehicle via the vehicle's drive wheels, and wherein the engine includes one or more combustion chambers and components configured to restrict airflow to the one or more combustion chambers during a reversing phase of the engine. The control device is configured to: - Based on at least one of the current weight estimate of the vehicle and the current total gear ratio between the engine and the drive wheels of the vehicle, determine whether the engine is operated in a fuel cut-off permitted mode or a fuel cut-off restricted mode during the engine's dragging phase.

[0056] Therefore, a control device is provided that can reduce lubricant delivery to the engine's combustion chamber while avoiding a significant reduction in vehicle drivability, handling smoothness, and driving experience. This is because, as the inventors of this disclosure recognize, each of the vehicle's current weight and current overall gear ratio has a significant impact on the negative effects of engine operation in fuel cut-off limiting mode on vehicle drivability, handling smoothness, and driving experience. Such negative effects may include, for example, an undesirable and / or unexpected reduction in vehicle deceleration rate, drivetrain oscillations, jerking, and impaired vehicle drivability.

[0057] Therefore, by determining whether the engine is operated in a fuel cut-off permitted mode or a fuel cut-off restricted mode during the engine's drag phase based on at least one of the vehicle's current weight estimate and the current total gear ratio between the engine and the vehicle's drive wheels, a control device is provided that can effectively reduce the delivery of lubricant to the engine's combustion chamber while ensuring drivability, smooth operation, and overall driving experience.

[0058] As another result, a control device is provided that can reduce particulate emissions and excessive lubricant consumption from the engine, while ensuring drivability, smooth operation, and overall driving experience.

[0059] In addition, a cost-effective control device is provided because it avoids the need to implement new hardware solutions and redesign and restructure various engine components in order to reduce the delivery of lubricant to the engine's combustion chamber.

[0060] Therefore, a control device is provided that overcomes or at least mitigates some of the aforementioned problems and disadvantages. Thus, the aforementioned objective is achieved.

[0061] It should be understood that all the various embodiments described for this method can be combined with the control device as described herein. That is, the control device according to the fourth aspect of the invention can be configured to perform any of the method steps of the first aspect of the invention.

[0062] According to a fifth aspect of this disclosure, the objective is achieved by a vehicle including an internal combustion engine configured to power the vehicle via the vehicle's drive wheels, wherein the engine includes one or more combustion chambers and components configured to restrict airflow to the one or more combustion chambers during a reversing phase of the engine, and wherein the vehicle includes control devices according to a fourth aspect of this disclosure.

[0063] Since the vehicle includes the control device according to the fourth aspect of this disclosure, a vehicle is provided in which lubricant can be effectively prevented from being delivered to the combustion chamber of the engine, while ensuring the drivability, smooth operation and overall driving experience of the vehicle.

[0064] Therefore, a vehicle is provided that overcomes or at least mitigates some of the aforementioned problems and disadvantages. Thus, the aforementioned objective is achieved.

[0065] Optionally, the engine includes a spark-ignition engine. Thus, a vehicle is provided that includes a spark-ignition engine, wherein lubricant delivery to the engine's combustion chamber can be effectively prevented, while ensuring the vehicle's drivability, handling smoothness, and overall driving experience.

[0066] Alternatively, the vehicle is a heavy-duty road vehicle, such as a truck or a bus. Thus, a heavy-duty road vehicle having at least some of the advantages described above is provided.

[0067] Further features and advantages of the invention will become apparent when examined in light of the appended claims and the following detailed description. Attached Figure Description

[0068] Various aspects of this disclosure, including its specific features and advantages, will be readily understood from the exemplary embodiments discussed in the following detailed description and accompanying drawings, wherein: Figure 1 A vehicle according to some embodiments is illustrated schematically. Figure 2 It shows Figure 1 The diagram shows a cross-sectional view of the internal combustion engine of the vehicle. Figure 3 The diagram shows the upper graph, which illustrates the change in inlet / outlet speed over time during operation in the engine's fuel cut-off permissible mode. Figure 1 and Figure 2 The fuel injection rate in one or more combustion chambers of the engine shown; and the lower graph showing the time variation of the fuel injection rate during engine operation in fuel cut-off limiting mode. Figure 1 and Figure 2 The fuel injection rate in one or more combustion chambers of the engine shown. Figure 4 The method of operating the internal combustion engine of a vehicle is illustrated schematically, and Figure 5 A computer-readable medium is shown. Detailed Implementation

[0069] The various aspects of this disclosure will now be described more fully. Similar reference numerals always refer to similar elements. For the sake of brevity and / or clarity, well-known functions or constructions will not be described in detail.

[0070] Figure 1 Vehicle 2 is schematically illustrated according to some embodiments. According to the illustrated embodiment, vehicle 2 is a truck, i.e., a type of heavy-duty road vehicle and a type of heavy-duty commercial vehicle. According to other embodiments, as mentioned herein, vehicle 2 can be another type of heavy or lighter manned or unmanned vehicle for land-based propulsion, such as a truck, bus, construction vehicle, tractor, automobile, etc.

[0071] Vehicle 2 includes a transmission 3 and an internal combustion engine 1. The internal combustion engine 1 is operatively connected to the drive wheels 27 of vehicle 2 via the transmission 3. In other words, the internal combustion engine 1 is configured to provide power to vehicle 2 through the transmission 3 and the drive wheels 27 of vehicle 2.

[0072] According to the illustrated embodiment, vehicle 2 includes two drive wheels 27 constituting the rear wheels of vehicle 2. Vehicle 2 also includes two non-drive wheels 27', which, according to the illustrated embodiment, constitute the front wheels of vehicle 2. However, according to another embodiment, vehicle 2 may include a different configuration of drive wheels and non-drive wheels.

[0073] The transmission 3 can be controlled between at least two different gears to provide at least two different gear ratios between the internal combustion engine 1 and the drive wheels 27 of the vehicle 2. These at least two different gear ratios can also be referred to as at least two different gear stages or at least two different gear ratios. As mentioned herein, the transmission 3 can also be referred to as a gearbox. As mentioned herein, the gear ratio between the internal combustion engine 1 and the drive wheels 27 of the vehicle 2 can be equal to the gear ratio between the output shaft of the internal combustion engine 1 and the drive wheels 27 of the vehicle 2.

[0074] Transmission 3 can be an automatic manual transmission, often abbreviated as AMT. An automatic manual transmission combines the efficiency of a manual transmission with the convenience of an automatic transmission. Unlike traditional automatic transmissions that use torque converters and planetary gear sets, an automatic manual transmission is characterized by a gearbox with a gear layout and a mechanical gear engagement and disengagement process similar to that of a manual transmission.

[0075] Furthermore, the automatic manual transmission may include a clutch that is controllable to disengage the input shaft of the transmission from the output shaft of the internal combustion engine 1. The automatic manual transmission may also include multiple actuators that are controllable to perform clutch disengagement and gear shifting via a shift linkage mechanism, thereby eliminating the need for the driver to manually operate the clutch pedal or shift lever.

[0076] Furthermore, according to some embodiments, as mentioned herein, the transmission 3 can be a conventional type of automatic transmission, commonly abbreviated as AT, which includes a torque converter and a planetary gear set. In this type of automatic transmission, the torque converter acts as a hydraulic coupling, replacing a clutch, thereby allowing the internal combustion engine 1 to remain running when the vehicle is stationary. The torque converter also provides the ability to multiply torque during acceleration. The planetary gear set typically includes a central sun gear, planetary gears rotating around the sun gear, and ring gears surrounding the planetary gears to provide a range of selectable gears. Additionally, this type of automatic transmission is typically equipped with a hydraulic control system that manages the operation of the torque converter and the engagement of the planetary gear set.

[0077] According to the illustrated embodiment, vehicle 2 includes an internal combustion engine 1 as the sole power source for powering vehicle 2. However, according to another embodiment, in addition to the internal combustion engine 1, vehicle 2 may also include one or more electric propulsion machines for powering vehicle 2. According to such embodiments, vehicle 2 may also be referred to as a hybrid electric vehicle.

[0078] The vehicle 2 also includes a control device 21. According to the illustrated embodiment, the control device 21 is operatively connected to the internal combustion engine 1 and the transmission 3.

[0079] exist Figure 1The diagram indicates the forward direction of movement fd and the reverse direction of movement rd of vehicle 2. The reverse direction of movement rd is opposite to the forward direction of movement fd of vehicle 2. Each of the forward direction of movement fd and the reverse direction of movement rd is parallel to the longitudinal direction Id of vehicle 2.

[0080] Figure 2 It shows Figure 1 The diagram shows a cross-sectional view of the internal combustion engine 1 of vehicle 2. For the sake of brevity and clarity, the internal combustion engine 1 will be referred to as a "combustion engine" or simply "engine 1" in some places herein. Unless otherwise indicated, reference will also be made to the following text. Figure 1 and Figure 2 .

[0081] The engine 1 includes one or more combustion chambers 4, each combustion chamber being defined by a cylinder 10 and a piston 12 disposed within the cylinder 10. Figure 2 In the diagram, only one cylinder 10 of engine 1 is visible, and therefore only one combustion chamber 4 and one piston 12 are also visible. However, engine 1 may include more than one cylinder 10, each cylinder defining the combustion chamber 4 together with the piston 12 arranged in the cylinder 10. Engine 1 may, for example, include four, six, or eight cylinders 10.

[0082] Engine 1 includes a crankcase defining a crankcase volume V. For the sake of brevity and clarity, Figure 2 The crankcase of engine 1 is not shown. Engine 1 also includes a crankshaft 16. The crankshaft 16 is arranged at least partially in the crankcase volume V. Each piston 12 of engine 1 is connected to the crankshaft 16 via a corresponding connecting rod 13.

[0083] As the crankshaft 16 rotates, the piston 12 moves forward and backward in the corresponding cylinder 10 between top dead center and bottom dead center. The engine 1 includes an air inlet 14, shown as an intake duct in the illustrated example engine. Furthermore, the engine 1 includes an air filter unit 47 configured to filter the air flowing into the air inlet 14.

[0084] According to the illustrated embodiment, engine 1 is a four-stroke internal combustion engine 1, which includes at least one intake valve 18 disposed in each cylinder 10, the at least one intake valve 18 being connected to an air inlet 14. Engine 1 also includes an intake valve control device 22 configured to control each intake valve 18 based on the rotational position of crankshaft 16. Engine 1 also includes at least one exhaust valve 24 disposed in each cylinder 10, the at least one exhaust valve 24 being connected to an exhaust outlet 26 of engine 1.

[0085] Engine 1 also includes an exhaust valve control unit 28, which is configured to control each exhaust valve 24 based on the rotational position of crankshaft 16. Figure 2 In the diagram, at least one intake valve 18 and at least one exhaust valve 24 are shown in their respective closed positions. In the closed position, each valve 18, 24 abuts against its respective valve seat to seal the fluid connection between the combustion chamber 4 and the respective air inlet 14 and exhaust outlet 26.

[0086] The intake valve control device 22 is arranged to control at least one intake valve 18 between a closed position and an open position by displacing at least one intake valve 18 in the direction of entering the cylinder 10. This opens the fluid connection between the air inlet 14 and the combustion chamber 4. Similarly, the exhaust valve control device 28 is arranged to control at least one exhaust valve 24 between a closed position and an open position by displacing at least one exhaust valve 24 in the direction of entering the cylinder 10. This opens the fluid connection between the combustion chamber 4 and the exhaust outlet 26. When valves 18 and 24 are displaced from the closed position to the open position, valves 18 and 24 are lifted from their seats.

[0087] The exhaust valve control unit 28 and the intake valve control unit 22 may each include one or more camshafts rotatably connected to the crankshaft 16, wherein the camshafts include cam lobes arranged to move valves 18, 24 to an open position by pressing the valve stems of valves 18, 24 as the camshaft rotates. According to another embodiment, the exhaust valve control unit 28 and / or the intake valve control unit 22 may include electric, pneumatic, or hydraulic actuators arranged to control the valves based on the rotational position of the crankshaft 16. The rotational position of the crankshaft 16 can be obtained using data from the crank angle sensor 29.

[0088] According to the illustrated embodiment, engine 1 is a spark-ignition engine, specifically an Otto engine with a spark ignition device 34. According to the illustrated embodiment, the spark ignition device 34 is a spark plug. The spark ignition device 34 is configured to ignite the air-fuel mixture in the combustion chamber 4.

[0089] Engine 1 can be configured to operate on gasoline, alcohol, gaseous fuels, or combinations thereof. Alcohols (such as ethanol) can be derived from renewable biomass. Gaseous fuels, also referred to as fuel gases, can encompass any type of fuel that is gaseous under normal ambient temperature and pressure conditions, can be stored under pressure in a pressure vessel, and can be burned in internal combustion engine 1 to produce useful work. Examples of such gaseous fuels are compressed natural gas (CNG), liquefied natural gas (LNG), liquefied petroleum gas (LPG), hydrogen (H2), biogas, and syngas. Many gaseous fuels can be derived from renewable sources, such as renewable biomass.

[0090] According to another embodiment, as mentioned herein, the internal combustion engine 1 can be a compression ignition engine, such as a diesel engine. Therefore, the internal combustion engine 1 can be configured to operate with diesel or diesel-like fuels (such as biodiesel, biomass-to-liquid (BTL) diesel, or gas-to-liquid (GTL) diesel). Diesel-like fuels (such as biodiesel) can be obtained from renewable sources, such as vegetable oils that primarily comprise fatty acid methyl esters (FAME). Diesel-like fuels can be produced from many types of oils (such as rapeseed oil (rapeseed methyl ester, RME) and soybean oil (soybean methyl ester, SME)). Furthermore, as mentioned herein, the internal combustion engine 1 can be a dual-fuel engine configured to operate with two different fuels (such as gaseous fuels and liquid fuels).

[0091] The engine 1 also includes a fuel supply device 6. The fuel supply device 6 is configured to supply fuel to one or more combustion chambers 4 of the engine 1. Figure 2 In this design, the fuel supply device 6 is depicted as a fuel injector configured to inject fuel into the air inlet 14 of the engine 1. However, as an alternative or additional method, the fuel supply device 6 of the engine 1 may include one or more other types of fuel supply devices, such as one or more fuel injectors configured to inject fuel directly into the combustion chamber 4 of the engine 1. Figure 2 As seen, the control unit 21 of the engine 1 is operatively connected to the fuel supply unit 6.

[0092] As further explained below, engine 1 includes an assembly 41 configured to restrict airflow to one or more combustion chambers 4 during the reversing phase of engine 1. Assembly 41 may also be referred to as an intake airflow control assembly, an intake airflow restriction assembly, etc.

[0093] according to Figure 2 In the embodiment depicted, component 41 includes a throttle valve 5 and an actuator 30, wherein the actuator 30 is configured to control the position of the throttle valve 5. The throttle valve 5 can be controlled by the actuator 30 between an open position and a position at least partially closed. Figure 1 In the diagram, the throttle valve 5 is schematically depicted in a partially closed position, in which the throttle valve 5 restricts the airflow to one or more combustion chambers 4 of the engine 1.

[0094] In addition, according to Figure 2In the embodiment depicted, component 41 further includes an intake valve phase shifter 31 and an exhaust valve phase shifter 32. The intake valve phase shifter 31 is controllable to limit airflow to one or more combustion chambers 4 by phase shift control of at least one intake valve 18 relative to the crankshaft 16. Similarly, the exhaust valve phase shifter 32 is controllable to limit airflow to one or more combustion chambers 4 by phase shift control of at least one exhaust valve 24 relative to the crankshaft 16.

[0095] The exhaust valve phasing device 31 and the intake valve phasing device 32 may each include a hydraulic device, for example using engine oil as the hydraulic fluid, to perform phase shift control of valves 18 and 24 relative to crankshaft 16. Such a hydraulic device may be part of a pulley (not shown) arranged to transmit rotation from crankshaft 16 to the camshaft of exhaust valve control device 28 and / or intake valve control device 22, wherein the hydraulic device is arranged to adjust the angular relationship between a first portion of the pulley connected to crankshaft 16 and a second portion of the pulley connected to the camshaft, in order to perform phase shift control of at least one intake valve 18 and / or at least one exhaust valve 24.

[0096] In embodiments where the exhaust valve control device 28 and / or the intake valve control device 22 include electric, pneumatic, or hydraulic actuators, the exhaust valve phase shifting device 32 and / or the intake valve phase shifting device 31 may perform phase shifting control on at least one valve 18, 24 in another manner (e.g., by electronic phase shifting control).

[0097] according to Figure 2 In the embodiment shown, the control unit 21 of the engine 1 is operatively connected to the assembly 41 via operatively connected to each of the actuator 30 of the throttle valve 5, the intake valve phase shifter 31, and the exhaust valve phase shifter 32. However, according to another embodiment, as mentioned herein, the assembly 41 may include only one or both of the actuator 30 of the throttle valve 5, the intake valve phase shifter 31, and the exhaust valve phase shifter 32 as described above. In such embodiments, the control unit 21 may be operatively connected only to such portions of the assembly 41.

[0098] As mentioned, component 41 is configured to restrict airflow to one or more combustion chambers 4 during the drag phase of engine 1. As used herein, the term drag phase refers to a scenario in which the crankshaft 16 of engine 1 is rotated by external torque.

[0099] This external torque can originate, for example, from the inertia of vehicle 2 during downhill coasting or when vehicle 2 is decelerating (where a gear is engaged in transmission 3 and the engine clutch is engaged). Typically, no fuel is supplied to combustion chamber 4 during the towing phase. Pumped air through combustion chamber 4 of engine 1 and frictional losses within engine 1 generate negative crankshaft torque, which in turn generates braking torque at drive wheels 27 of vehicle 2 via the drivetrain of vehicle 2.

[0100] According to the embodiments described herein, control device 21 is configured to obtain a current weight estimate wE of vehicle 2, i.e., an estimate of the current weight of vehicle 2. According to some embodiments, control device 21 may be configured to obtain the current weight estimate wE from an input unit arranged in the driver's environment of vehicle 2, from external sensors, etc.

[0101] Alternatively or additionally, control device 21 may be configured to obtain the current weight estimate wE of vehicle 2 by estimating the current weight estimate wE based on data from multiple onboard sensors (i.e., sensors arranged on vehicle 2). Such multiple sensors may include one or more of the following: an inclinometer and / or gyroscope configured to provide data representing the current orientation of vehicle 2 relative to a local gravitational field; an accelerometer configured to measure the current acceleration of vehicle 2; a vehicle speed sensor configured to monitor the current speed of vehicle 2; one or more sensors configured to measure data indicating the current power output of internal combustion engine 1, such as the current output torque and current speed of internal combustion engine 1; one or more load sensors configured to provide data representing the current weight of cargo loaded into vehicle 2; one or more strain gauge sensors configured to provide data on the relative positions of various parts of the suspension assembly of vehicle 2; and multiple tire pressure monitoring sensors.

[0102] according to Figure 1 In the embodiment shown, vehicle 2 includes a coupling assembly 51 for attaching a trailer to vehicle 2. For simplicity and clarity, Figure 1 The trailer is not shown. The coupling assembly 51 may be a fifth-wheel coupling assembly. As mentioned herein, vehicle 2 may include a trailer. In other words, as mentioned herein, vehicle 2 may include... Figure 1 The vehicle 2 depicted herein and the connecting component 51 connected via the vehicle 2 Figure 1 The vehicle 2 depicted herein is a trailer. In other words, according to the embodiments described herein, vehicle 2 may be a combination of vehicles including a tractor and a trailer articulatedly connected to vehicle 2.

[0103] According to some embodiments, the trailer includes multiple load sensors configured to provide data representing the current weight of cargo loaded in the trailer, wherein the control unit 21 is configured to receive data from the multiple load sensors via a signal cable extending between the towing vehicle and the trailer. According to such embodiments, the control unit 21 may be configured to obtain a current weight estimate wE of the vehicle based on data from the multiple load sensors of the trailer.

[0104] Furthermore, according to the embodiments described herein, the control device 21 is configured to obtain the current total gear ratio tr between the engine 1 and the drive wheels 27 of the vehicle 2. As mentioned herein, the current total gear ratio tr refers to the total gear ratio between the crankshaft 16 of the internal combustion engine 1 and the drive wheels 27 of the vehicle 2, also known as the gear ratio.

[0105] As mentioned, according to the illustrated embodiments, the transmission 3 can be controlled between at least two different gears to provide at least two different gear ratios between the engine 1 (i.e., the crankshaft 16 of the engine 1) and the drive wheels 27 of the vehicle 2. According to these embodiments, the control device 21 is configured to obtain the current total gear ratio tr between the engine 1 and the drive wheels 27 of the vehicle 2 based on the currently engaged gear in the transmission 3. Furthermore, the control device 21 can calculate the current total gear ratio tr between the engine 1 and the drive wheels 27 of the vehicle 2 using the gear ratio provided by the currently engaged gear in the transmission 3 and factors, constants, or variables representing the total gear ratio provided by the remainder of the vehicle 2's drivetrain. Such remainder may include intermediate gear assemblies, reduction gear assemblies, differential gear assemblies, the rolling radius of the drive wheels 27, etc.

[0106] Furthermore, according to the illustrated embodiment, the control device 21 is configured to control component 41 during the reversing phase of the engine 1 to restrict airflow to one or more combustion chambers 4 of the engine 1. The control device 21 may be configured to control component 41 to restrict airflow to one or more combustion chambers 4 by controlling the actuator 30 of the throttle valve 5 to move the throttle valve 5 to at least a partially closed position. Alternatively or additionally, the control device 21 may be configured to control component 41 to restrict airflow to one or more combustion chambers 4 by controlling the intake valve phase shifting device 31 and / or the exhaust valve phase shifting device 32 to perform phase shifting control of the intake / exhaust valves 18, 24 relative to the crankshaft 16.

[0107] Control device 21 can be configured to input engine back-dragging requirements and / or vehicle deceleration requirements, and can respond thereto control component 41 to restrict airflow to one or more combustion chambers 4 of engine 1. Engine back-dragging requirements and / or vehicle deceleration requirements can be input from actuators (such as accelerator pedals, brake pedals, etc.) arranged in the driver environment 55 of vehicle 2. Alternatively or additionally, engine back-dragging requirements and / or vehicle deceleration requirements can be input from at least partially autonomous driving systems of vehicle 2, from communication devices, or from another type of device or system of vehicle 2.

[0108] As mentioned herein, at least partially autonomous driving systems can be configured to control the speed and / or steering of vehicle 2 based on data from sensor components of vehicle 2. The at least partially autonomous driving system 2 can be a fully or partially autonomous driving system capable of driving vehicle 2 in a at least partially autonomous manner based on input from sensor components. Furthermore, as mentioned herein, the at least partially autonomous driving system can be a cruise control system, an adaptive cruise control system, a semi-autonomous driving system, or a fully autonomous driving system.

[0109] Figure 3 The upper graph shows the change in the entry time t during AM operation in the fuel cut-off permissible mode of engine 1. Figure 1 and Figure 2 The fuel injection rate iF in one or more combustion chambers 4 of engine 1 is shown; and the lower graph shows the fuel injection rate iF as a function of time t during operation in the fuel cut-off limiting mode LM of engine 1. Figure 1 and Figure 2 The fuel injection rate iF in one or more combustion chambers 4 of the engine 1 shown.

[0110] Unless otherwise indicated, see also below. Figures 1-3 In more detail, Figure 3 The upper graph includes a horizontal axis showing time t and the vertical fuel injection rate iF entering one or more combustion chambers 4 of engine 1 during fuel cut-off permitted mode AM operation. Similarly, Figure 3 The lower part of the graph includes a horizontal axis showing time t and a vertical axis showing the fuel injection rate iF entering one or more combustion chambers 4 of engine 1 during fuel cut-off mode LM operation.

[0111] Figure 4 A method 100 for operating the internal combustion engine 1 of vehicle 2 is schematically shown. The internal combustion engine can be, according to reference... Figures 1 to 3 The illustrated embodiment includes an internal combustion engine 1. Similarly, the vehicle can be based on... Figure 1Vehicle 2 of the embodiment shown. Furthermore... Figure 3 It also describes Figure 4 Some of the method steps in method 100 shown are 101, 101', 102, 103, 104, 105, 106, 108, 110, 111, 112, 113, 115, 117, 120, 122, 124, 130, 140, 142, 150, 160, and 162. Therefore, unless otherwise indicated, reference will also be made to these steps in the following text. Figures 1 to 4 .

[0112] As further explained below, the control unit 21 of engine 1 can be configured to execute Figure 4 Any one of the method steps 101, 101', 102, 103, 104, 105, 106, 108, 110, 111, 112, 113, 115, 117, 120, 122, 124, 130, 140, 142, 150, 160, and 162 of the method 100 shown.

[0113] Method 100 is a method of operating an internal combustion engine 1 of a vehicle 2, wherein the engine 1 is configured to provide power to the vehicle 2 via drive wheels 27 of the vehicle 2, and wherein the engine 1 includes one or more combustion chambers 4 and an assembly 41 configured to restrict airflow to the one or more combustion chambers 4 during a reversing phase of the engine 1. Method 100 includes the following steps: - Based on at least one of the current weight estimate wE of vehicle 2 and the current total gear ratio tr between engine 1 and drive wheels 27 of vehicle 2, determine whether engine 1 is operated in fuel cut-off permitted mode AM or fuel cut-off restricted mode LM during the reverse drag phase of engine 1.

[0114] In other words, according to the embodiments herein, the control device 21 is configured to determine whether the engine 1 is operated in fuel cut-off permitted mode AM or fuel cut-off restricted mode LM during the reverse drag phase of the engine 1, based on at least one of the current weight estimate wE of the vehicle 2 and the current total gear ratio tr between the engine 1 and the drive wheels 27 of the vehicle 2.

[0115] In this way, as further explained in this article, lubricant can be effectively prevented from being delivered from the crankcase volume V to the combustion chamber 4 of the engine 1, while ensuring the drivability, smooth operation and overall driving experience of the vehicle 2.

[0116] As mentioned, according to the illustrated embodiment, vehicle 2 includes a transmission 3 that can be controlled between at least two different gears to provide at least two different gear ratios between engine 1 and drive wheels 27 of vehicle 2. Figure 3 and Figure 4 As indicated in these embodiments, method 100 includes the following steps: - Based on the current gear engaged in transmission 3, obtain the current total gear ratio tr between engine 1 and drive wheels 27 of vehicle 2.

[0117] The step of obtaining the current total gear ratio tr between engine 1 and drive wheels 27 of vehicle 2 can be based on calculations using the gear ratio provided by the current gear engaged in transmission 3 and factors, constants, or variables representing the total gear ratio provided by the rest of the transmission system of vehicle 2. Such rest may include intermediate gear units, reduction gear units, differential gear units, rolling radius of drive wheels 27, etc.

[0118] In addition, such as Figure 3 and Figure 4 As indicated in the document, according to the illustrated embodiment, the method includes the following steps: - Obtain the current weight estimate wE for vehicle 2, 101'.

[0119] The steps to obtain the current weight estimate wE of vehicle 2 (101') can be used to obtain the above reference. Figure 1 and Figure 2 One or more of the devices used to elucidate the current weight estimate wE.

[0120] Clearly, the steps of obtaining the current total gear ratio tr and the current weight estimate wE of 101 can be performed before the step of determining whether engine 1 is operated in fuel cut-off permitted mode AM or fuel cut-off restricted mode LM during the reverse drag phase of engine 1 at step 104.

[0121] According to some embodiments, method 100 includes the following steps: - During the backward drag phase of engine 1, the airflow to one or more combustion chambers 4 of engine 1 is restricted.

[0122] The operation of the control component 41 can be used to perform steps that restrict airflow to one or more combustion chambers 4 of the engine 1. As mentioned, according to the illustrated embodiment, component 41 includes a throttle valve 5 and an actuator 30.

[0123] According to these embodiments, the step of restricting airflow to one or more combustion chambers 4 of the engine 1 can be performed by controlling the throttle valve 5 to at least a partially closed position. As understood from the above, in these embodiments, the throttle valve 5 can be controlled to at least a partially closed position by controlling the operation of the actuator 30.

[0124] Furthermore, according to the illustrated embodiment, component 41 also includes an intake valve phase shifter 31 and an exhaust valve phase shifter 32. According to these embodiments, the step of restricting airflow to one or more combustion chambers 4 of the engine 1 can be performed by controlling the intake valve phase shifter 31 and / or the exhaust valve phase shifter 32 to perform phase shift control of the intake / exhaust valves 18, 24 relative to the crankshaft 16.

[0125] Moreover, such as Figure 3 and Figure 4 As indicated in the document, according to the illustrated embodiment, the method includes the following steps: - Set parameter p to 102 based on the current weight estimate wE and the current total gear ratio tr. - If parameter p is equal to or below threshold th, then engine 105 operates in fuel cut-off permitted mode AM during the dragging phase, and - If parameter p is higher than threshold th, then engine 1106 is operated in fuel cut-off mode LM during the drag phase of engine 1.

[0126] In other words, according to the illustrated embodiment, the control device 21 is configured to: - Set parameter p based on the current weight estimate wE and the current total gear ratio tr. - If parameter p is equal to or below threshold th, then engine 1 operates in fuel cut-off permitted mode AM during the dragging phase, and - If parameter p is higher than threshold th, then engine 1 is operated in fuel cut-off mode LM during the drag phase of engine 1.

[0127] More in detail, such as Figure 3 and Figure 4 As shown, according to the illustrated embodiment, the step of setting parameter p102 includes the following steps: - Set parameter p based on the ratio between the current weight estimate wE and the current total gear ratio tr.

[0128] In other words, according to these embodiments, the control device 21 is configured to set the parameter p based on the ratio between the current weight estimate wE and the current total gear ratio tr.

[0129] like Figure 3 As can be seen in the upper curve diagram, according to the illustrated embodiment, the steps of operating engine 105 in fuel cut-off permissible mode AM during the dragging phase include the following steps: - During the non-restricted time period nrt, 108 is allowed to stop the fuel supply to one or more combustion chambers 4.

[0130] In other words, according to these embodiments, the control device 21 is configured to operate the engine 1 in fuel cut-off permitted mode AM during the drag phase by allowing the cessation of fuel supply to one or more combustion chambers 4 during the non-restrictive time period nrt.

[0131] The control device 21 can be configured to stop the fuel supply to one or more combustion chambers 4 by controlling the operation of the engine's fuel supply device 6 during a non-restricted time period nrt, until the engine back-dragging demand is cancelled, for example, by receiving a positive engine torque demand, vehicle acceleration demand, etc.

[0132] In addition, such as Figure 3 and Figure 4 As seen in the illustrated embodiment, method 100 includes the following steps: - Set the duration d1 of the 110 fuel cutoff time period fc1, and during LM operation in fuel cutoff limiting mode: - Stop the fuel supply from 130 to one or more combustion chambers 4 during the fuel cutoff period fc1, and - After the fuel cut-off period fc1, 140 is started to supply fuel to one or more combustion chambers 4.

[0133] In other words, according to these embodiments, the control device 21 is configured to set the duration d1 of the fuel cut-off period fc1 and to operate the engine 1 in fuel cut-off restriction mode LM by stopping the fuel supply to one or more combustion chambers 4 during the fuel cut-off period fc1 and starting the fuel supply to one or more combustion chambers 4 after the fuel cut-off period fc1.

[0134] As used herein, the phrase "stop supplying fuel to one or more combustion chambers 4" can mean not supplying fuel to one or more combustion chambers 4, i.e., using a zero fuel injection rate iF. Figure 3 As seen in the lower part of the graph, the fuel injection rate iF is zero during the fuel cutoff period fc1. Furthermore, as... Figure 3 As seen in the lower part of the graph, the fuel injection rate iF is at the determined level dA during the fuel supply time period fs1 that occurs after the fuel supply to one or more combustion chambers 4 is initiated at step 140.

[0135] like Figure 4 As can be seen from the example, according to the illustrated embodiment, the step of setting the duration d1 of the fuel cutoff time period fc1 includes the following steps: - Set the duration d1 of the fuel cut-off period fc1 based on the current engine speed rpm of engine 1.

[0136] In other words, according to the illustrated embodiment, the control device 21 is configured to set the duration d1 of the fuel cut-off period fc1 based on the current engine speed rpm of the engine 1. The current engine speed rpm of the engine 1 can be obtained, for example, using data from the crank angle sensor 29 of the vehicle 2.

[0137] In addition, such as Figure 4 As can be seen from the example, according to the illustrated embodiment, the step of setting the duration d1 of the fuel cutoff time period fc1 includes the following steps: - The duration d1 increases by 112 as the engine speed (rpm) increases, and - The duration d1 decreases by 113 as the rotational speed (rpm) decreases.

[0138] In other words, in these embodiments, the control device 21 is configured to set the duration d1 of the fuel cut-off period fc1 by increasing the duration d1 as the rotational speed rpm increases and decreasing the duration d1 as the rotational speed rpm decreases.

[0139] Moreover, such as Figure 4 As can be seen from the example, according to the illustrated embodiment, the step of setting the duration d1 of the fuel cutoff time period fc1 includes the following steps: - Set the duration d1 of the 115 fuel cut-off period fc1 based on the current total gear ratio tr.

[0140] In other words, according to the illustrated embodiment, the control device 21 is configured to set the duration d1 of the fuel cut-off period fc1 based on the current total transmission ratio tr between the engine 1 and the drive wheels 27 of the vehicle 2.

[0141] In addition, such as Figure 4 As can be seen from the example, according to the illustrated embodiment, the step of setting the duration d1 of the fuel cutoff time period fc1 includes the following steps: - Based on the current total gear ratio tr, set the duration d1 of the 117 fuel cut-off period fc1, such that the duration d1 of the fuel cut-off period fc1 increases as the total gear ratio tr decreases, and decreases as the total gear ratio tr increases.

[0142] In other words, in these embodiments, the control device 21 is configured to set the duration d1 of the fuel cut-off period fc1 based on the current total gear ratio tr, such that the duration d1 of the fuel cut-off period fc1 increases as the total gear ratio tr decreases and decreases as the total gear ratio tr increases.

[0143] like Figure 3 and Figure 4 As can be seen from the illustration, according to the illustrated embodiment, method 100 includes the following steps: - Based on the current engine speed (rpm) of engine 1, set the duration (df1) of the 120 fuel supply time period (fs1). And after the step of starting 140 to supply fuel to one or more combustion chambers 4: - During the fuel supply period fs1, fuel 142 is supplied to one or more combustion chambers 4.

[0144] In other words, in these embodiments, the control device 21 is configured to set the duration df1 of the fuel supply time period fs1 based on the current engine speed rpm of the engine 1, and to control the fuel supply device 6 to supply fuel to one or more combustion chambers 4 during the fuel supply time period fs1 after the initiation of fuel supply to one or more combustion chambers 4. Figure 3 As can be seen in the lower part of the graph, as mentioned above, the fuel injection rate iF is controlled to the determined level dA during the fuel supply period fs1.

[0145] like Figure 3 and Figure 4 As can be seen from the illustration, according to the illustrated embodiment, method 100 includes the following steps: - During the second fuel cut-off period fc2 following the fuel supply period fs1, the fuel supply to one or more combustion chambers 4 is stopped by 150.

[0146] Therefore, in these embodiments, the control device 21 is configured to stop the fuel supply to one or more combustion chambers 4 during a second fuel cut-off period fc2 following the fuel supply period fs1. As mentioned herein, the fuel cut-off period fc1 may also be referred to as the first fuel cut-off period fc1.

[0147] In addition, such as Figure 3 and Figure 4 As indicated in the diagram, according to the illustrated embodiment, method 100 includes the following steps: - Set the duration d2 of the second fuel cut-off period fc2 based on at least one of the current engine speed rpm and the current total gear ratio tr of engine 1.

[0148] In other words, according to these embodiments, the control device 21 is configured to set the duration d2 of the second fuel cut-off period fc2 based on at least one of the current engine speed rpm and the current total gear ratio tr of the engine 1.

[0149] In addition, such as Figure 3 and Figure 4 As can be seen from the illustration, according to the illustrated embodiment, method 100 includes the following steps: - After the second fuel cut-off period fc2, 160 is started to supply fuel to one or more combustion chambers 4.

[0150] Therefore, according to the illustrated embodiment, the control device 21 is configured to initiate fuel supply to one or more combustion chambers 4 after the second fuel cut-off time period fc2.

[0151] like Figure 3 and Figure 4 As can be seen from the illustration, according to the illustrated embodiment, method 100 includes the following steps: - Based on the current engine speed rpm of engine 1, set the duration df2 of the second fuel supply time period fs2 to 124. And after the step of starting 160 to supply fuel to one or more combustion chambers 4: - During the second fuel supply period fs2, fuel 162 is supplied to one or more combustion chambers 4.

[0152] In other words, in these embodiments, the control device 21 is configured to set the duration df2 of the second fuel supply period fs2 based on the current engine speed rpm of the engine 1, and to control the fuel supply device 6 to supply fuel to one or more combustion chambers 4 during the second fuel supply period fs2 after the initiation of fuel supply to one or more combustion chambers 4. Figure 3 As can be seen in the lower part of the graph, as mentioned above, the fuel injection rate iF is controlled to the determined level dA during the second fuel supply period fs2. As mentioned in this article, the fuel supply period fs1 can also be referred to as the first fuel supply period fs1.

[0153] Therefore, in general, according to the illustrated embodiment, the control device 21 is configured to alternately supply fuel to one or more combustion chambers 4 of the engine 1 during fuel cut-off time periods fc1, fc2 and supply fuel to one or more combustion chambers 4 during fuel supply time periods fs1, fs2 when operating in fuel cut-off limiting mode LM. This alternation can continue until, for example, an engine backdraft demand is cancelled by receiving a positive engine torque demand, vehicle acceleration demand, etc.

[0154] Similarly, in general, according to the illustrated embodiment, the control device 21 is configured to stop the fuel supply to one or more combustion chambers 4 during a non-restrictive time period nrt when operating in fuel cut-off permissible mode AM, until the engine dragging demand is cancelled, for example, by receiving a positive engine torque demand, vehicle acceleration demand, etc.

[0155] As described above, positive engine torque demand and / or vehicle acceleration demand can be received in control unit 21 from actuators (e.g., accelerator pedals) arranged in the driver environment 55 of vehicle 2. Alternatively or additionally, positive engine torque demand and / or vehicle acceleration demand can be input from at least a partially autonomous driving system of vehicle 2, from a communication device, or from another type of device or system of vehicle 2.

[0156] As used in this article, vehicle acceleration demand refers to the demand for vehicle 2 to accelerate in the positive direction of movement fd of vehicle 2. Similarly, vehicle deceleration demand (also known as vehicle slowdown demand) refers to the demand for vehicle 2 to slow down (i.e., decelerate) in the positive direction of movement fd of vehicle 2.

[0157] It should be understood that all the various embodiments described for method 100 can be combined with the control device 21 as described herein. That is, the control device 21 can be configured to perform any of the method steps 101, 101', 102, 103, 104, 105, 106, 108, 110, 111, 112, 113, 115, 117, 120, 122, 124, 130, 140, 142, 150, 160, and 162.

[0158] Figure 5 A computer-readable medium 200 is shown, including instructions that, when executed by a computer, cause the computer to perform a method 100 according to some embodiments of the present disclosure. According to some embodiments, the computer-readable medium 200 includes a computer program that includes instructions that, when executed by a computer, cause the computer to perform the method 100 according to some embodiments. The computer may be included in a control device 21.

[0159] Those skilled in the art will understand that the method 100 for operating the internal combustion engine 1 of vehicle 2 can be implemented by program instructions. These programming instructions typically constitute a computer program that, when executed in control unit 21, ensures that control unit 21 performs desired control, such as method steps 101, 101', 102, 103, 104, 105, 106, 108, 110, 111, 112, 113, 115, 117, 120, 122, 124, 130, 140, 142, 150, 160, and 162 as described herein. The computer program is typically part of a computer program product, which includes a suitable digital storage medium on which the computer program is stored, such as… Figure 5 The computer-readable medium 200 is shown. In other words, a computer program product can be a computer-readable medium 200, and a computer program can be stored in a computer-readable medium 200.

[0160] Control device 21 may include a computer, which may take the form of substantially any suitable type of hardware or hardware / firmware device implemented using processing circuitry, such as, but not limited to, a processor, central processing unit (CPU), controller, arithmetic logic unit (ALU), digital signal processor, application-specific integrated circuit (ASIC), circuitry for digital signal processing (DSP), microcomputer, field-programmable gate array (FPGA), system-on-a-chip (SoC), programmable logic unit, microprocessor, application-specific integrated circuit, or any other device capable of electronically performing operations in a defined manner, or other processing logic capable of interpreting and executing instructions. As used herein, the term "computer" may refer to a system of processing circuitry comprising multiple processing circuitry, such as any, some, or all of the processing circuitry mentioned above.

[0161] The control device 21 may also include a memory unit, to which a computer can be connected. This memory unit provides the computer with stored program code and / or stored data, such as data that the computer might need to enable it to perform calculations. The computer may also be adapted to store partial or final results of calculations in the memory unit. The memory unit may include physical means for temporarily or permanently storing data or programs, i.e., sequences of instructions. According to some embodiments, the memory unit may include integrated circuits comprising silicon-based transistors. In different embodiments, the memory unit may include, for example, a memory card, flash memory, USB storage, a hard disk, or other similar volatile or non-volatile memory units for storing data, such as, for example, ROM (Read-Only Memory), PROM (Programmable Read-Only Memory), EPROM (Erasable PROM), EEPROM (Electrically Erasable PROM), etc.

[0162] Control device 21 is connected to components of internal combustion engine 1 and / or vehicle 2 to receive and / or transmit input and output signals. These input and output signals may include waveforms, pulses, or other properties that can be detected as information by the input signal receiving device and converted into signals that can be processed by control device 21. These signals can then be supplied to a computer. One or more output signal transmitting devices may be arranged to convert calculation results from the computer into output signals for transmission to other parts of the vehicle control system and / or to one or more components to which the signals are directed. Each connection to the corresponding component of vehicle 2 for receiving and transmitting input and output signals may take one or more forms, such as cable, data bus (e.g., CAN (Controller Area Network) bus, MOST (Media Directed Transmission) bus, or some other bus configuration), or wireless connection.

[0163] In the illustrated embodiment, vehicle 2 includes control device 21, but may alternatively be implemented wholly or partially in two or more control devices, two or more control units, or two or more control units.

[0164] Control systems in modern vehicles typically include a communication bus system, which comprises one or more communication buses for connecting multiple electronic control units (ECUs) or controllers to various components on the vehicle. Such control systems can contain a large number of control units, and it should be noted that specific functions may be shared among two or more of them. Therefore, as those skilled in the art will certainly appreciate, the type of vehicles and engines of the kind of concern herein are typically equipped with more… Figure 1 and Figure 2 The document describes significantly more control devices.

[0165] For example, computer-readable medium 200 may be provided in the form of a data carrier carrying computer program code for performing at least some of the method steps 101, 101', 102, 103, 104, 105, 106, 108, 110, 111, 112, 113, 115, 117, 120, 122, 124, 130, 140, 142, 150, 160, and 162 according to some embodiments of method 100 when loaded into one or more computers of control device 21. The data carrier may be, for example, a CD-ROM disk (e.g., Figure 5 The computer-readable medium 200 may be a non-transitory computer-readable medium, such as a ROM (Read-Only Memory), PROM (Programmable Read-Only Memory), EPROM (Erasable PROM), flash memory, EEPROM (Electrically Erasable PROM), hard disk, memory stick, optical storage device, magnetic storage device, or any other suitable medium that can hold machine-readable data in a non-transitory manner, such as a magnetic disk or magnetic tape. Therefore, in some embodiments, the computer-readable medium 200 may be a non-transitory computer-readable medium, such as a tangible electronic, magnetic, optical, infrared, electromagnetic, and / or semiconductor system, device, and / or apparatus. The computer-readable medium 200 may also be provided as computer program code on a server and may be remotely downloaded to the control device 21, for example, via an Internet or intranet connection or via other wired or wireless communication systems.

[0166] It should be understood that the above description is illustrative of various exemplary embodiments, and the invention is defined only by the appended independent claims. Those skilled in the art will recognize that modifications can be made to the exemplary embodiments without departing from the scope of the invention as defined by the appended independent claims, and different features of the exemplary embodiments can be combined to produce embodiments other than those described herein.

[0167] As used herein, the term “comprising / comprises” is open-ended and includes one or more of the stated features, elements, steps, components, or functions, but does not exclude the presence or addition of one or more other features, elements, steps, components, functions, or groups thereof.

Claims

1. A method (100) of operating an internal combustion engine (1) of a vehicle (2), wherein the engine (1) is configured to power the vehicle (2) via drive wheels (27) of the vehicle (2), and wherein the engine (1) includes one or more combustion chambers (4) and an assembly (41) configured to restrict airflow to the one or more combustion chambers (4) during a dragging phase of the engine (1). And the method (100) described therein includes the following steps: - Based on at least one of the current weight estimate (wE) of the vehicle (2) and the current total gear ratio (tr) between the engine (1) and the drive wheels (27) of the vehicle (2), determine (104) whether the engine (1) is operated in fuel cut-off permitted mode (AM) or fuel cut-off restricted mode (LM) during the back-dragging phase of the engine (1).

2. The method (100) according to claim 1, wherein the method (100) comprises the following steps: - Set parameter (p) (102) based on the current weight estimate (wE) and the current total gear ratio (tr). - If the parameter (p) is equal to or below the threshold (th), then the engine (1) is operated (105) in the fuel cut-off permitted mode (AM) during the dragging phase, and - If the parameter (p) is higher than the threshold (th), the engine (1) is operated (106) in the fuel cut-off restriction mode (LM) during the drag phase of the engine (1).

3. The method (100) according to claim 2, wherein the step of setting (102) the parameter (p) includes the following steps: - Set the parameter (p) based on the ratio between the current weight estimate (wE) and the current total transmission ratio (tr).

4. The method (100) according to any one of the preceding claims, wherein the method comprises the following steps during operation in the fuel cut-off permission mode (AM): - During the non-restrictive time period (nrt), (108) the fuel supply to the one or more combustion chambers (4) may be stopped.

5. The method (100) according to any one of the preceding claims, wherein the method comprises the following steps: - Set the duration (d1) of the fuel cut-off period (fc1) (110). And during operation in the aforementioned fuel cut-off limiting mode (LM): - During the fuel cut-off period (fc1), the fuel supply to the one or more combustion chambers (4) is stopped (130), and - After the fuel cut-off period (fc1), start (140) to supply fuel to the one or more combustion chambers (4).

6. The method (100) of claim 5, wherein the step of setting (110) the duration (d1) of the fuel cut-off time period (fc1) comprises the following steps: - Based on the current speed (rpm) of the engine (1), set (111) the duration (d1) of the fuel cut-off period (fc1).

7. The method (100) of claim 6, wherein the step of setting (111) the duration (d1) of the fuel cut-off time period (fc1) comprises the following steps: - The duration (d1) increases with increasing rotational speed (rpm) (112), and - The duration (d1) decreases as the rotational speed (rpm) decreases (113).

8. The method (100) according to any one of claims 5-7, wherein the step of setting the duration (d1) of the fuel cut-off time period (fc1) of (110) comprises the following steps: - Set the duration (d1) of the fuel cut-off period (fc1) based on the current total gear ratio (tr).

9. The method (100) of claim 8, wherein the step of setting (115) the duration (d1) of the fuel cut-off time period (fc1) comprises the following steps: - Based on the current total gear ratio (tr), set (117) the duration (d1) of the fuel cut-off period (fc1) such that the duration (d1) of the fuel cut-off period (fc1) increases as the total gear ratio (tr) decreases and decreases as the total gear ratio (tr) increases.

10. The method (100) according to any one of claims 5-9, wherein the method (100) comprises the following steps: - Based on the current speed (rpm) of the engine (1), set (120) the duration (df1) of the fuel supply period (fs1). And after the step of starting (140) to supply fuel to the one or more combustion chambers (4): - During the fuel supply period (fs1), fuel (142) is supplied to the one or more combustion chambers (4).

11. The method (100) of claim 10, wherein the method (100) comprises the following steps: - During the second fuel cut-off period (fc2) following the fuel supply period (fs1), the fuel supply to the one or more combustion chambers (4) is stopped (150).

12. The method (100) according to claim 11, wherein the method (100) comprises the following steps: - The duration (d2) of the second fuel cut-off period (fc2) is set based on at least one of the current speed (rpm) of the engine (1) and the current total gear ratio (tr).

13. The method (100) according to any one of the preceding claims, wherein the vehicle (2) includes a transmission (3) controllable between at least two different gears to provide at least two different gear ratios between the engine (1) and the drive wheels (27) of the vehicle (2), and wherein the method (100) includes the following steps: - Based on the current gear engaged in the transmission (3), obtain (101) the current total gear ratio (tr) between the engine (1) and the drive wheels (27) of the vehicle (2).

14. A computer program comprising instructions that, when executed by a computer, cause the computer to perform the method (100) according to any one of claims 1-13.

15. A computer-readable medium (200) including instructions that, when executed by a computer, cause the computer to perform the method (100) according to any one of claims 1-13.

16. A control device (21) configured to control the operation of an internal combustion engine (1) of a vehicle (2), wherein the engine (1) is configured to power the vehicle (2) via drive wheels (27) of the vehicle (2), and wherein the engine (1) includes one or more combustion chambers (4) and an assembly (41) configured to restrict airflow to the one or more combustion chambers (4) during a dragging phase of the engine (1). And the control device (21) therein is configured to: - Based on at least one of the current weight estimate (wE) of the vehicle (2) and the current total gear ratio (tr) between the engine (1) and the drive wheels (27) of the vehicle (2), determine whether the engine (1) is operated in fuel cut-off permitted mode (AM) or fuel cut-off restricted mode (LM) during the back-dragging phase of the engine (1).

17. A vehicle (2) comprising an internal combustion engine (1) configured to power the vehicle (2) via drive wheels (27) of the vehicle (2), wherein the engine (1) comprises one or more combustion chambers (4) and an assembly (41) configured to restrict airflow to the one or more combustion chambers (4) during a dragging phase of the engine (1), and wherein the vehicle (2) comprises a control device (21) according to claim 16.

18. The vehicle (2) according to claim 17, wherein the engine (1) is a spark ignition engine.

19. The vehicle (2) according to claim 17 or 18, wherein the vehicle (2) is a heavy road vehicle, such as a truck or a bus.

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