Control of a device for adjusting the intake gas pressure in an engine system, as well as computer program, computer program product, system and motor vehicle therewith

Abstract

Method for controlling an element (40) in an engine system, wherein the system comprises an internal combustion engine (10) connected to an air intake system and an exhaust system and is also mechanically connected to a transmission, wherein the element (40) is arranged in the air intake system and is configured to adjust the gas pressure in the air intake system, wherein the method is characterized in that the element (40) is controlled on the basis of at least one first parameter P1, wherein the first parameter P1 is associated with a gas pressure P IC is located upstream of element (40) in the air intake system.

Description

Technical field of the invention

[0001] The present invention relates to a method for controlling an element in an engine system. The invention further relates to a computer program, a computer program product, a system, and a motor vehicle containing such a system. Background of the invention

[0002] When shifting from a first gear G1 to a second higher gear G2 in a transmission system, it is desirable that the current engine rotational speed ω can be reduced quickly and in a controlled manner when the transmission is in a neutral state between first gear G1 and second gear G2.

[0003] Fig. Figure 1 shows a situation in which an upshift from a first (lower) gear G1 to a second, higher gear G2 occurs (in this case, from 10th to 12th gear). This example assumes that the driver keeps the accelerator pedal depressed throughout the entire upshift. The upshift takes place as follows: 1) Upshifting is initiated either manually or automatically, depending on the transmission system, whereupon the engine torque is reduced so that zero engine torque is received by the transmission; 2) The first gear G1 is then disengaged, which means that the transmission is in a neutral state (N); 3) when the transmission is in a neutral state, an actual engine rotational speed ω is set to match the engine speed for the higher gear G2 (i.e., synchronized with it); 4) When the engine rotational speed ω is synchronized, the higher gear G is engaged; and 5) The motor torque can then be increased so that it corresponds to a desired motor torque.

[0004] In step 3) above, it is desirable for the engine speed to decrease from a first engine speed ω1 to a second, lower speed ω2, so that an upshift can be performed quickly. One advantage of a rapid decrease in engine speed ω is that the interruption of the drive motor torque is shorter, meaning that the vehicle does not lose as much speed during the upshift.

[0005] A reduction in engine speed typically occurs when the engine system stops injecting fuel into the engine. This slows the engine down due to internal friction and the engine's pumping work, thus reducing the current engine speed ω. The pumping work of any engine, also known as pumping losses, is the work required to pump air into the engine cylinder(s) before ignition and to pump burnt gas out of the cylinder(s) after combustion. This means that, all other things being equal, greater pumping work results in a faster reduction in engine speed ω, while less pumping work results in a slower reduction in engine speed ω.

[0006] To control the pumping work in heavy motor vehicles such as trucks and buses, an exhaust flap is usually installed in the exhaust pipe through which the exhaust gases are routed. Closing / blocking the exhaust flap leads to a build-up of high exhaust pressure, resulting in increased pumping work in the engine. Alternatively, or in combination with an exhaust flap, a variable geometry turbocharger (VGT) is used to limit the flow range for exhaust gases and thereby increase the pumping work. The VGT can, for example, control how much exhaust gas flows onto the turbine blades.

[0007] In certain situations, the pumping work gained by means of an exhaust flap and / or a VGT is insufficient when an extremely rapid reduction in engine speed is desired. Furthermore, neither an exhaust flap nor a VGT is included in all engine systems / vehicles, meaning that the engine's pumping work cannot be controlled at all in such systems / vehicles.

[0008] A solution to this problem is provided by Swedish patent application 1150210-1 (applicant: Scania), published as SE 1150210 A1. According to this patent application, the pumping work is increased or decreased by controlling the gas pressure in the internal combustion engine's air intake system. One proposed solution involves rapidly reducing the gas pressure in the intake manifold to the cylinders to achieve a strong pumping work, thus facilitating a rapid reduction in engine speed in conjunction with upshifting. Once the higher gear is engaged, the throttle valve is fully opened.

[0009] From DE 10 2007 043 174 A1, an engine system with an internal combustion engine is known. The internal combustion engine comprises an intake manifold, a throttle valve, a turbocharger, and a bypass valve for diverting exhaust gas around the turbocharger. The bypass valve is controlled based on pressure on an upstream side of the throttle valve.

[0010] Furthermore, document US 2004 / 0106498A1 discloses a control system for an internal combustion engine in which a throttle valve located in an intake system is controlled during a gear change based on an estimated reduction in torque.

[0011] Documents DE 195 09 139 A1 and DE 10 2007 060 216 A1 disclose further alternative control systems for adjusting engine torque during gear changes. Brief description of the invention

[0012] One object of the present invention is to provide a solution that eliminates, in whole or in part, the problem and / or disadvantages of known solutions for controlling an element arranged to control a gas pressure in an intake system.

[0013] Another object of the present invention is to provide a solution that enables more efficient use of an air reservoir in an air intake system of an engine system.

[0014] The solution according to the invention is achieved by a method with the features of claim 1, by a computer program with the features of claim 16, by a computer program product with the features of claim 17, by a system with the features of claim 18, and by a motor vehicle with the features of claim 19. Advantageous further developments are set forth in the dependent claims.

[0015] According to a first aspect of the invention, the above-mentioned problems are solved by means of a method for controlling an element in an engine system comprising an internal combustion engine connected to an air intake system and an exhaust system and further mechanically connected to a transmission, wherein the element is arranged in the air intake system, and the element is controlled on the basis of at least one first parameter P1, wherein the first parameter P1 is related to a gas pressure P IC is located upstream of the element in the air intake system.

[0016] Various embodiments of the above-mentioned method are defined in the independent claims directed to the method. A method according to the invention can also be implemented in a computer program that executes the method according to the invention when run.

[0017] According to a second aspect of the invention, the above-mentioned problems are solved by a system comprising an internal combustion engine connected to an air intake system and an exhaust system, and furthermore mechanically connected to a transmission, wherein the system comprises: an element that is arranged in the air intake system and is designed to control the gas pressure in the air intake system, and a control device connected to the element and configured to control the element; wherein the control device comprises: a receiving unit designed to receive at least one first parameter P1, which is associated with a gas pressure P IC is located upstream of the element in the air intake system, and a control unit designed to control the element based on at least one first parameter P1.

[0018] The above-mentioned system is preferably arranged in a motor vehicle such as a bus, a truck, or other similar motor vehicle. The system can further be modified so that, after suitable modifications, embodiments of the system correspond to different embodiments of the method according to the invention.

[0019] A method and a system according to the present invention provide a solution that, among other things, enables the efficient, precise, and controlled use of available air / gas in an air intake system. As a result, good engine torque response during upshifting and downshifting can be achieved. Furthermore, the present invention can serve to improve the function of exhaust aftertreatment and other aspects relating to combustion and exhaust gas purification in engine systems.

[0020] Additional advantages and applications of the invention are presented in the following detailed description. Brief description of the characters

[0021] The present invention is described below with reference to the accompanying figures, wherein: - Fig. 1 schematically shows a motor speed and motor torque for upshifting; - Fig. 2 schematically shows a motor system; - Fig. Figure 3 schematically shows a time diagram of an upshifting process; - Fig. Figure 4 schematically shows a time diagram of a downshifting process; - Fig. Figure 5 shows an example of a control device. Detailed description of the invention

[0022] Fig. Figure 2 shows an exemplary engine system, which includes an air intake system connected to an internal combustion engine 10, e.g., a diesel engine. The air intake system consists of an air intake opening through which air is drawn in and conveyed via one or more pipes and, in this case, an intercooler 50 to one or more cylinders in the engine 10 for combustion with supplied fuel such as gasoline or diesel. A throttle valve is also arranged in the air intake system between the intercooler and the engine cylinders, and the air intake system may also include air purification components. The function of the air intake system is to supply air for combustion in the engine cylinder(s). An exhaust gas recirculation (EGR) system may also be connected to the air intake system.Exhaust gas recirculation is achieved by returning exhaust gases to the intake side, and for this purpose the EGR loop normally has an EGR valve; see . Fig. 2. The primary purpose of EGR is to dilute the air for combustion and reduce the proportion of oxygen in the combustion gas. This lowers the combustion temperature and reduces the formation of NO. x is prevented.

[0023] The function of the throttle valve is to control the gas pressure in the air intake system. The throttle valve is typically plate-shaped. It is usually controlled by a control unit through one or more control elements to regulate the flow of air through the intake manifold based on the desired amount of air entering the cylinders. When the amount of air (airflow) in the engine is restricted by the throttle valve, the gas pressure in the intake manifold decreases; conversely, when the amount of air in the engine is increased, the gas pressure in the intake manifold increases, all other factors being equal.

[0024] Throttle valves or other types of valves are usually controlled by one or more control elements, which may be pneumatically, hydraulically, or by electric motors. Furthermore, most throttle valves are designed to assume various positions in the pipe at varying speeds v, since the throttle valve position often follows the engine rotational speed ω, thus adjusting the flow of air into the engine to the desired combustion in the cylinders, although the engine load also affects the throttle valve position.

[0025] The system in Fig. Figure 2 also includes a turbocharger system comprising a compressor 61 mechanically connected via a shaft to a turbocharger turbine 62. The air drawn into the engine system is compressed in the compressor and then cooled in the charge air cooler before flowing through the throttle valve to the cylinders via the intake manifold. The exhaust gases from the combustion process in the cylinders are passed through the turbocharger turbine, which imparts velocity to the turbocharger compressor via the shaft, and then the exhaust gases are discharged from the engine system via an exhaust system, which may, for example, include an exhaust manifold with an exhaust flap (not shown) that controls the pressure in the exhaust manifold.The exhaust gases then flow through an aftertreatment system, which includes a diesel particulate filter (DPF), a selective catalytic reduction (SCR) catalyst, a diesel oxidation catalyst (DOC), and / or other aftertreatment components, if such a system is present in the engine. The aftertreatment components are listed in... Fig. 2 not shown.

[0026] The engine is also mechanically connected to a transmission (not shown), e.g., via a clutch assembly, which may consist of an automatically controlled clutch and is controlled by the vehicle's control systems via a control unit that can also control the transmission. In vehicles, the transmission is usually a manual transmission, an automated transmission such as an automatic transmission, an automated manual transmission (AMT), a dual-clutch transmission (DCT), or a continuously variable transmission (CVT / IVT).

[0027] A method according to the invention leads to an element 40, which is configured to control a gas pressure in an intake system of an internal combustion engine, being controlled on the basis of one or a plurality of first parameters P1. The one or a plurality of first parameters P1 is associated with a gas pressure P IC upstream of element 40 in the air intake system, e.g. in an intercooler or in a pipe that connects an air intake opening to an intake pipe to the engine cylinders.

[0028] The invention thus provides a solution that enables efficient, accurate and controlled use of the quantity of air / gas available in an air intake system, since the element 40 is controlled on the basis of one or a plurality of first parameters P1, which are related to the gas pressure P ICupstream of element 40, the relationship between the amount of air / gas and the gas pressure can be easily derived from the ideal gas law, which describes the relationships between pressure, volume, temperature, and amount of substance.

[0029] One application of the present invention is, for example, to prevent an undesirable accumulation of particles in an aftertreatment system comprising a particulate filter designed to capture a portion of the exhaust gas particles. These particles are deposited in the aftertreatment system, which can lead to reduced efficiency and an increased pressure drop in the aftertreatment system, which in turn leads to higher fuel consumption and a greater need for regeneration. The application of an increased gas pressure P ICWhen the accelerator pedal is depressed (not necessarily in conjunction with shifting gears), a method or system according to the invention makes it possible to initially supply the combustion with a higher lambda value (see below for lambda) than is the case with combustion according to the prior art, so that the accumulation of particles in the aftertreatment system can be reduced, which in turn leads to lower fuel consumption and fewer regeneration cycles. This is achieved by using the first parameter P1 to control element 40, since the first parameter P1 has proven to be a well-suited input parameter in the control algorithm. It is also noted that other fields of application relating to combustion and exhaust gas purification are suitable for a solution according to the invention.

[0030] Another preferred application of the present invention lies in connection with upshifting or downshifting in a transmission, since the invention also provides a solution that makes it possible to efficiently utilize built-up air pressure in the intake system to achieve a torque response in conjunction with the engagement of the next gear during downshifting or upshifting. Regardless of the application, according to a further preferred embodiment of the invention, it is also suitable for other elements for controlling the gas flow to be controlled based on the first parameter P1, in order to utilize the air in the intake system more efficiently. Examples of such elements commonly found in motor vehicles include, among others, the VGT and the EGR valve.

[0031] That the first parameter P1 is related to the gas pressure P ICThe relationship upstream of the element is understood to mean that the first parameter P1 is related to the actual gas pressure P IC upstream of element 40 in the air intake system, it is identical, but also that it has a direct or indirect correlation with the gas pressure P IC exhibits. For example, the first parameter P1 can be derived as a function of one or a multitude of gas pressure values ​​upstream of the element, or it can show some other dependency correlation with it. The function or correlation can include constants, coefficients, or other mathematical expressions. Furthermore, the function or correlation can take on discrete, logical, or continuous values, depending on the application.

[0032] One way to obtain a direct value for the first parameter P1 is to use one or a multitude of pressure sensors / transmitters in the air intake system upstream of element 40.

[0033] This is a simple approach that yields fast and accurate values ​​for the first parameter P1. However, it requires specific hardware, such as sensors and signals for signal transmission. An indirect value for the first parameter P1 can also be obtained using sensors / transmitters.

[0034] Another way to obtain a value for the first parameter P1 is to use a model for the gas pressure in the air intake system upstream of element 40, rather than using sensors. The specific hardware described above is then not required, but instead, power calculations and data storage are needed, as well as potentially other hardware, such as turbine speedometers, mass flow sensors, and pressure sensors, located at points other than upstream of element 40.

[0035] The first parameter, P1, can be modeled, for example, as the amount of air / gas available in the volume comprising the air intake system (e.g., pipes and intercooler), which can be considered a reservoir. The extent to which the air / gas in the reservoir is sufficient in connection with, for example, depressing the accelerator pedal for second gear (G2), can be calculated using additional parameters such as engine speed and volumetric efficiency. Another way to model the gas pressure in the air intake system is to estimate the flow into and out of the intercooler, if one is installed. The intercooler is then modeled as a volume and flow constraint (it typically consists of a multitude of narrow pipes that result in a pressure drop). The flow constraint leads to a pressure drop. Since the volume of the intercooler is known, the pressure within it can be calculated.The flow rate into the charge air cooler can be obtained, for example, by using a compressor model or a mass flow sensor, while the flows out of the charge air cooler can be calculated using throttling equations and calculating the flow into the engine. However, it should be noted that it is also possible to combine the use of pressure sensors (or other suitable sensors / senders) with various models to obtain the value of the first parameter P1.

[0036] One or a plurality of first parameters P1 are used, for example, as input parameters in a control algorithm configured to adjust the gas pressure upstream of element 50 to a desired value. The control algorithm can be of many different types and may, for example, be a simple algorithm that considers only the first parameter P1 and uses one or a plurality of threshold values ​​(e.g., an upper and a lower threshold) to determine which control action should be taken. A more sophisticated control algorithm also considers one or a plurality of additional parameters, as detailed in the following description of various embodiments of the invention.

[0037] According to a further embodiment of the invention, the element 40 is controlled such that the gas pressure P ICupstream of the element in the direction of a so-called setpoint P IC or target value is set. This means that the control algorithm controls element 40 so that the gas pressure P IC in the direction of a specific target value P T is set. This leads to a feedback algorithm. The value of the setpoint P IC This can depend on the desired goal, such as good torque response in conjunction with gear changes or improved exhaust gas purification. The target value P IC It can also depend on time, so that the value changes during a process, such as in the main phases of gear shifting, which are associated with different times; see, for example, Fig. 3 and Fig. 4.

[0038] According to a further preferred embodiment of the invention, the element 40 is configured to be controlled for adjusting a gas pressure in an intake system based on one or a plurality of first parameters P1 in conjunction with an upshift or downshift in a transmission 30 from a first gear G1 to a second gear G2. The fact that the element 40 is controlled based on one or a plurality of first parameters P1 in conjunction with an upshift or downshift is to be understood as meaning that this control takes place from a period before the disengagement of first gear until a period after the engagement of second gear. The exact duration of these periods depends on the application, but the control of the element 40 generally takes place in conjunction with the reduction and increase in torque to which each upshift or downshift results; see engine torque curves in Fig. 3 and Fig. 4.

[0039] Fig. 3 and Fig. 4 show time diagrams for engine speed, engine torque, throttle position (how open or closed the throttle valve is), and a gas pressure P. IC upstream and a gas pressure P IM downstream of element 40 during a power-up ( Fig. 3) and a downshift ( Fig. 4) from first gear to second gear in an engine system according to the system in Fig. 2. In this regard, it should be noted that Fig. Figure 2 shows an embodiment of the invention in which the engine system comprises a turbocharger system (in this case a VGT) and an intercooler. Furthermore, the element 40 for adjusting the gas pressure in the air intake system is, in this example, a throttle valve, but could also be any suitable element with the same or a corresponding function, i.e., that of adjusting the gas pressure in the air intake system. Shifting up

[0040] How Fig. Figure 3 shows that the throttle valve (corresponding to element 40) can be moved to a more closed position even during the upshift start procedure, i.e., during a reduction in engine torque associated with upshifting. Moving the throttle valve to a more closed position results in a pressure drop across the throttle valve. This leads to a lower gas pressure in the intake manifold (downstream of element 40) than the pressure in the charge air cooler (upstream of element 40). The throttle valve is controlled so that the gas pressure in the charge air cooler is used during the reduction in engine torque associated with upshifting, i.e., the gas pressure P ICUpstream of element 40, the pressure rises or is substantially maintained during this part of the upshift when first gear is to be disengaged. If an intercooler is installed in the air intake system, the method according to the invention attempts to keep the pressure substantially as high as possible, or to maintain or increase the pressure within it, since a large volume (reservoir), consisting of the pipe and the intercooler itself, is present between the turbocharger compressor, which pressurizes the system and the throttle valve. Maintaining or increasing the gas pressure in this volume causes it to act as an air reservoir, the volume of which can be stored for subsequent combustion during the upshift, resulting in very good torque response.If, on the other hand, the gas pressure cannot be maintained or increased, the throttle valve is controlled in such a way that, according to a further embodiment of the invention, the gas pressure in the charge air cooler is kept as high as possible.

[0041] According to the state of the art, the VGT normally serves to adjust the pressure upstream of the element in conjunction with gear changes. To rapidly reduce torque during shifting, the VGT (and any EGR flap valve) is closed, causing high back pressure to build up on the exhaust side. This means that the engine speed drops rapidly due to the back pressure when the shift process reaches point C in the Fig. 3. The disadvantage of this process is that the compressor is not necessarily operating in its most efficient range, resulting in a slower build-up or even a decrease in intake-side pressure, leading to weak torque response during gear changes. Furthermore, there is a clear risk of the turbocharger turbine speed decreasing, resulting in a prolonged recovery time. Conversely, if, in conjunction with the VGT control, a high mass flow rate through the compressor is prioritized, the exhaust backpressure is low, resulting in a prolonged reduction in engine speed during gear changes. There is also a significant risk of unnecessarily depleting the intake air reservoir.To achieve better results regarding the utilization of air / gas upstream of the throttle valve, the throttle valve control can be combined with the control of the VGT (and any EGR valve) according to the present invention. This means that, according to a further embodiment of the invention, the VGT is also controlled based on the first parameter P1.

[0042] During an upshift, the VGT and the throttle valve must be controlled so that the pumping work between times C and D is minimized. Fig. 3 assumes a sufficient size, while at the same time a high gas pressure P IC must be maintained until time D. Sufficient pumping work means that the pumping work is large enough to reduce the motor speed by at least a certain amount over a specific period during the synchronization phase. Typical values ​​can range between 1200 and 1500 seconds.-1 The VGT (Variable Gearbox Throttle) is designed to achieve rapid gear changes. This is primarily accomplished by keeping the VGT closed, thus generating high exhaust backpressure. The VGT is then controlled to a specific exhaust backpressure (such as 6 bar), and the VGT control can then be adjusted at time A. Fig. 3 begins, as the system knows that an upshift is about to take place. In this way, the system can build up exhaust backpressure in a controlled manner until the shift process reaches time C in Fig. 3 reached. At time A in Fig. 3. At the same time, the system closes the throttle valve as far as possible without risking oil spillage.

[0043] The risk of suction must also be managed during gear changes. If a suction hazard occurs, the mass flow rate through the compressor must be reduced, which in turn leads to a decrease in gas pressure P. IC This can be achieved by opening either the throttle valve or the VGT, which means that the VGT can also be controlled based on the first parameter P1 in this case. Alternatively, according to a further embodiment of the invention, both the throttle valve and the VGT can be opened in a simultaneous process.

[0044] According to an alternative upshifting process, the VGT can be controlled towards optimal turbine performance instead of prioritizing pumping work; that is, the VGT can be controlled to generate the best possible mass flow from the compressor and thereby the gas pressure P. ICThis process does not result in as high an exhaust backpressure as the process described above, but it is extremely useful in cases where the actual upshift time is not critical. The throttle valve is then controlled to be as closed as possible without causing oil to be drawn in or carried over. An example of this type of gearshift would be during acceleration downhill, i.e., in a case where the loss of speed due to slower synchronization during gearshift is less.

[0045] According to an additional embodiment of the invention, the VGT is controlled such that the gas pressure P IC upstream of the element in the direction of a so-called setpoint P IC or target value is set. This means that the control algorithm controls the VGT so that the gas pressure P ICin the direction of a specific target value P T The setpoint value can depend on the desired goal, such as good torque response during gear changes or improved exhaust gas purification. The setpoint can also depend on time, so that the value changes during a process, for example, during the different phases of a gear change. Furthermore, the control of the VGT and element 40 can be coordinated so that both the VGT and the element are controlled in such a way that the gas pressure P IC upstream of the element in the direction of the setpoint P T is being discontinued.

[0046] As for the EGR valve, it should ideally always be closed. If good torque response is desired, the air for combustion is not mixed with exhaust gases. On the other hand, the system may be required to use the EGR during gear changes to meet legal emissions regulations. The EGR valve is normally closed as soon as the system detects that a gear change has been initiated. When the accelerator pedal is pressed, the system may open the EGR valve to reduce emissions. One way to accomplish this is to control the EGR valve to a specific, calibrated amount of EGR (although the opposite situation also occurs, where the EGR valve adjusts the air volume and the VGT adjusts the amount of EGR).

[0047] It is further noted that the throttle valve is also controlled such that the flow of air gas at the throttle valve decreases in conjunction with the reduction in engine torque associated with disengaging first gear G1. Furthermore, the throttle valve is controlled such that the gas flow at the throttle valve increases in conjunction with the increase in engine torque associated with engaging second gear G2, as described in Fig. Figure 3 shows that when first gear G1 is disengaged and the engine torque decreases, no engine torque is requested, and therefore the amount of fuel injected is zero. When the engine reaches its target speed for second gear, zero torque is requested, so the engine maintains the target speed, allowing second gear G2 to engage.

[0048] During upshifting, the throttle valve is controlled so that the gas flow at the throttle valve increases from a period T1 before the engagement of second gear G2. The period T1 takes on a value in the range of 0.01 to 0.50 s, and values ​​around 0.1 s (0.05-0.30 s) are suitable with regard to the response times of existing actuators in motor vehicles. Other parameters that influence the value of period T1 include the time required to fill the volume located downstream of the throttle valve (40) but upstream of the cylinders. This period T1 is thus used to compensate for the time delay associated with the actuators and the aforementioned volumes. The advantage of this process is that a direct torque response, i.e., without delay, is achieved.

[0049] Shortly before the engine reaches its target rotational speed (G2) for second gear, the throttle valve opens appropriately to ensure the correct amount of air, and therefore the correct air-fuel mixture, is present so that the engine can maintain zero torque. This results in an increase in gas pressure downstream of the throttle valve (P). IM and a reduction in gas pressure upstream of the throttle valve P IC .

[0050] Once second gear (G2) is engaged, the engine torque increases, for example, to the torque desired by the driver. Higher engine torque results in a larger quantity of fuel being injected into the engine cylinders, thus requiring a greater quantity of air in the cylinders. The throttle valve is adjusted to maintain the required lambda value. Finally, when the excess stored air in the intake system is exhausted, the throttle valve is moved to an open position (or optionally a fully open position, if necessary) to ensure that the air supply to the engine is not restricted. It is clear from the above that certain other conditions (sub-conditions) may apply to the control of this element; that is, the element can also be controlled taking into account one or more additional parameters.

[0051] For this reason, according to one embodiment, element 40 is also controlled on the basis of at least a second parameter P2, which is related to lambda λ, i.e., a fuel-air mixture in the one or a plurality of cylinders of the internal combustion engine 10. Lambda λ is a recognized term in internal combustion engine theory and can be defined, for example, as: λ=WAirWFuel where W Luft the mass flow rate of air into the cylinder, W KraftstoffThe mass flow rate of fuel into the cylinder and Z are constants. The constant Z is chosen such that lambda λ is 1 when stoichiometric conditions prevail, meaning the amount of air is exactly sufficient for the amount of fuel to be burned. If lambda λ is less than 1, there is insufficient air for a given amount of fuel injected into the cylinders. If lambda λ is greater than 1, there is an excess of air, and more air is present than is needed for combustion. Since the fuel does not come into contact with all the available air, a theoretical value of 1 for lambda λ is not sufficient for good combustion; rather, in a diesel engine, lambda typically takes on a value greater than 1 for good combustion (for example, lambda might be approximately 1.3 in this case).

[0052] In simpler terms, according to another embodiment of the invention, the throttle valve can be controlled such that it does not open fully after second gear is engaged, as this would cause the pressure built up in the charge air cooler to escape, resulting in an unnecessary excess of air for combustion. Instead, the throttle valve (and the VGT and / or the EGR valve) are controlled so that the pressure built up in the charge air cooler is supplied to the combustion process as needed by maintaining lambda at the lowest permissible value (lambda λ consequently assumes a value of approximately 1). This shortens or eliminates the torque limitation time during gear changes, which is a significant advantage. According to another embodiment of the invention, this results in element 40 being adjusted towards a desired setpoint for lambda λ.This can be done to achieve good torque response in conjunction with gear changes, but also to improve combustion and / or exhaust gas purification in the engine system.

[0053] According to a further embodiment, the element 40 is also controlled based on at least a third parameter P3, which is related to the flow rate and pressure drop in the turbocharger compressor of the engine system. This obviously applies if the engine system includes a turbocharger system with such a compressor. It is well known to those skilled in the art that a turbocharger system can begin to develop suction, which must be avoided. To avoid suction, a certain ratio between the flow rate and the pressure drop must assume a value on the "right" side of the suction limit. Suction can be avoided by also including the third parameter P3 in the control of the element. According to one embodiment, the element 40 is thus controlled such that the flow rate and the pressure drop in the compressor 61 are kept at the same value, so that the turbine does not develop suction.

[0054] According to a further embodiment of the invention, the element is also controlled on the basis of at least a fourth parameter P4, which is associated with a gas pressure P IM downstream of element 40, there is a risk of oil being carried over into the cylinders if the gas pressure P IM downstream of element 40, the pressure is too low. This leads to increased oil consumption and emissions, as the oil is burned in the engine. For this reason, it is appropriate that the gas pressure P IM downstream of the element, the pressure should be kept above a threshold value, the threshold value preferably being below 0.9 bar (90,000 Pa).

[0055] Furthermore on Fig. 3 With reference to this, an embodiment of a method according to the invention can be implemented during a power-up process in accordance with the following description of the process: A. In A, an upshift is initiated by reducing the engine torque and simultaneously causing the throttle valve to enter a more closed position, so that the pressure in the charge air cooler is maintained or increased; B. In B, the engine continues to run in a torque-free state, so that first gear G1 can be disengaged, and a suitable control loop can ensure that the engine actually continues to run in a torque-free state. C. At step C, first gear G1 is disengaged and no torque is requested, and the throttle valve is simultaneously moved to an even more closed position, thus maintaining or increasing the pressure in the charge air cooler. At step C, the current engine speed ω also decreases to a desired target engine speed for second gear G2, and a suitable control loop can ensure that this occurs. D. At point D, the throttle valve begins to open, causing the pressure in the intake manifold downstream of the throttle valve to increase. The throttle valve opens over a period of time T1 before the engagement of second gear G2, as described above. E. At E, the actual rotational speed of the engine is the same as the target rotational speed of the engine, second gear G2 is engaged, and the throttle valve is controlled to a desired value for λ. F. At F, the torque is increased; G. In position G, the excess air in the charge air cooler is exhausted and the throttle valve is held fully or partially open, so that the engine is not throttled with respect to air; and The desired torque is achieved at H. Downshifting

[0056] When downshifting, the throttle valve (or element 40) is controlled in a manner similar to that described above for upshifting. However, there are several differences in the control of the element between these two shifting examples. One difference between upshifting and downshifting is that the engine torque never drops to zero when downshifting, as described above. Fig. Figure 4 is shown. Another difference is that the engine torque must increase during a downshift so that second gear G2 can be engaged. Yet another difference is that the gas flow at the throttle valve is not increased before second gear G2 engages, but rather during the engagement of second gear G2.

[0057] How Fig. Figure 4 shows that the throttle valve may already be in a more closed position in conjunction with initiating the gear shift, i.e., during a reduction in engine torque associated with downshifting. Once first gear (G1) is disengaged, engine torque is requested, causing the engine speed to increase. When the target engine speed for second gear (G2) is reached, zero torque is requested, allowing the engine to maintain the target speed so that second gear (G2) can be engaged. Once second gear (G2) is engaged, the engine torque is increased to, for example, the torque requested by the driver, and the throttle valve is subsequently controlled in the same way as during upshifting.

[0058] A control algorithm for the element can also be based on one or a multitude of the second P2, third P3 and fourth P4 parameters, as described above in connection with a downshift.

[0059] Furthermore on Fig. 4 With reference to this, an embodiment of a method according to the invention can be implemented during a downshift according to the following description of the process: A. In A, downshifting is initiated by reducing the engine torque and simultaneously causing the throttle valve to move to a more closed position, thus maintaining or increasing the pressure in the charge air cooler; B. In B, the engine continues to run in a torque-free state, so that first gear G1 can be disengaged, and a suitable control loop can ensure that the engine actually continues to run in a torque-free state. C. At step C, first gear G1 is disengaged and higher torque is requested, and the throttle valve is simultaneously controlled so that the pressure in the charge air cooler can be maintained or increased, depending on the condition that a desired value for λ is achieved; at step C, the current engine speed ω also decreases to a desired target engine speed for second gear G2, and a suitable control loop can ensure that this is the case. D. In position D, the actual rotational speed of the engine is the same as the target rotational speed of the engine, and the engine torque can be reduced, second gear G2 is engaged, and the throttle valve is controlled to a desired value for λ. E. At E, the engine torque is increased; F. In case F, the excess air in the charge air cooler is exhausted and the throttle valve is held fully or partially open, so that the engine is not throttled with respect to air; and The desired torque is achieved at G.

[0060] The present method can be implemented in a control system, for example, a control device configured to control all or part of an engine system in a motor vehicle. The control system may further include additional control devices configured to control other functions, such as an external load, external heating elements, etc. Control devices of the type shown are typically configured to receive one or more sensor signals for various parts of the vehicle and from other control devices. These control devices are also typically configured to send control signals and / or information signals to various vehicle components and / or other control devices. The control devices may also include or be connected to a processing unit so that they calculate / simulate the predicted parameter values.

[0061] The control systems in modern vehicles typically consist of a communication bus system, comprising one or more communication buses, to connect a number of electronic control units (ECUs) or control units / controllers and various components located within the vehicle. Such a control system can encompass a large number of control devices, and responsibility for a particular function within the motor vehicle can be distributed among one or more control devices.

[0062] Control is effected by programmed instructions. These programmed instructions typically consist of a computer program which, when executed in a computer or control device, causes the computer / control device to perform the desired control procedure, such as the method according to the invention. The computer program usually forms part of a computer program product, wherein the computer program product comprises a suitable digital non-volatile / permanent / durable storage medium 121 on which the computer program is stored.The digital non-volatile / permanent / durable storage medium 121 consists of a suitable memory such as: a ROM (Read-Only Memory), a PROM (Programmable Read-Only Memory), an EPROM (Erasable PROM), a Flash memory, an EEPROM (Electrically Erasable PROM), a hard disk unit, etc., and is set up in or in conjunction with the control device, whereupon the computer program is executed by the control device.

[0063] An exemplary control device (control device 208) is shown schematically in Fig.Figure 5 shows the control device, wherein the control device can in turn comprise a computing unit 120, which can consist, for example, of any suitable type of processor or microcomputer, such as a digital signal processing circuit (digital signal processor, DSP) or an application-specific integrated circuit (ASIC). The computing unit 120 is further connected to a storage unit 121, which provides the computing unit 120 with, for example, the stored program code 126 and / or the stored data that the computing unit 120 needs to be able to perform arithmetic operations. The computing unit 120 is also configured to store partial or final results of the arithmetic operations in the storage unit.

[0064] Furthermore, the control device for receiving and transmitting input and output signals is equipped with elements / devices 122, 123, 124, and 125. These input and output signals can contain waveforms, pulses, or other attributes that can be recognized by the input signal receiving devices as information for processing by the processing unit. The output signal sending devices 123 and 124 are configured to convert calculation results from the processing unit into output signals for transmission to other parts of the vehicle control system and / or the component(s) for which the signals are intended.Each of the connections to devices for receiving and sending corresponding input and output signals can consist of one or more cables, a data bus such as a CAN bus (Controller Area Network), a MOST bus (Media Oriented Systems Transport) or another bus configuration, or a wired or wireless connection.

[0065] The present invention further relates to a system corresponding to any embodiment of the method according to the invention. This means that the system can be modified with suitable changes according to any embodiment of the method according to the invention. The system comprises an internal combustion engine 10 connected to an air intake system and an exhaust system. The internal combustion engine is also mechanically connected to a transmission 30. The system further comprises an element 40 arranged in the air intake system and configured to adjust the gas pressure in the air intake system. Additionally, the system comprises a control device connected to the element 40 and configured to control the element 40. In this case, the control element comprises a receiving unit and a control unit. The receiving unit is configured to receive at least one first parameter P1, which is associated with a gas pressure P. ICThe control unit is located upstream of element 40 in the air intake system. Furthermore, it is configured to control element 40 based on at least one first parameter P1, for example, in connection with upshifting or downshifting from first gear G1 to second gear G2, or for efficient combustion and / or exhaust gas purification. It should be noted that the control device can be a separate control device, part of another control device that controls one or more elements or units, or part of a larger control system with multiple control devices.

[0066] One or a plurality of systems according to the invention can be arranged in a motor vehicle such as a bus, a truck, or the like. According to a preferred embodiment of the invention, the internal combustion engine of the system is a diesel engine.

[0067] Finally, it should be noted that the present invention is not limited to the embodiments of the invention described above, but rather relates to and encompasses all embodiments within the scope of protection of the attached independent claims.

Claims

[1] Method for controlling an element (40) in an engine system, wherein the system comprises an internal combustion engine (10) connected to an air intake system and an exhaust system and is also mechanically connected to a transmission, wherein the element (40) is arranged in the air intake system and is configured to adjust the gas pressure in the air intake system, wherein the method characterized by is that the element (40) is controlled on the basis of at least one first parameter P1, wherein the first parameter P1 is associated with a gas pressure P IC is located upstream of element (40) in the air intake system. [2] Method according to claim 1, wherein the element (40) is controlled on the basis of the first parameter P1 such that it controls the gas pressure P IC adjusts. [3] Method according to claim 2, wherein the element (40) is controlled such that it controls the gas pressure P IC in the direction of a target value P T for gas pressure PIC adjusts. [4] Method according to one of the preceding claims, wherein the element (40) is controlled on the basis of the first parameter P1 in conjunction with upshifting or downshifting from a first gear G1 to a second gear G2. [5] Method according to claim 4, wherein the element (40) is controlled on the basis of the first parameter P1 such that the gas pressure P IC during a section of upshifting or downshifting, it is kept as high as possible, increases, or is essentially maintained. [6] Method according to any one of claims 3 to 5, wherein the element (40) is controlled on the basis of the first parameter P1 such that a gas flow at the element (40) is: during a reduction in torque in conjunction with the disengagement of first gear G1; and / or during an increase in torque in conjunction with the engagement of second gear G2. [7] Method according to claim 6, wherein the upshifting or downshifting relates to an upshift and the element (40) is controlled on the basis of the first parameter P1 such that the gas flow at the element (40) takes place for a period of time T1 before the engagement of the second gear. [8] Method according to claim 7, wherein the time period T1 takes on a value in the range of 0.01 to 0.50 seconds. [9] Method according to one of the preceding claims, wherein the element (40) is further controlled on the basis of at least one second parameter P2, wherein the second parameter P2 is related to lambda λ, i.e. a fuel-air mixture in the one or a plurality of cylinders of the internal combustion engine (10). [10] Method according to one of the preceding claims, wherein the engine system further comprises a turbocharger system comprising a compressor (61) mechanically connected to a turbine (62), and the element (40) is further controlled on the basis of at least a third parameter P3, wherein the third parameter P3 is related to a flow rate and a pressure drop in the compressor (61). [11] Method according to one of the preceding claims, wherein the element (40) is further controlled on the basis of at least a fourth parameter P4, wherein the fourth parameter P4 is associated with a gas pressure P IM is related downstream of element (40). [12] Method according to claim 11, wherein the element (40) is controlled such that the gas pressure P IM downstream of element (40) is greater than a threshold value, where the threshold value is less than 0.9 bar. [13] Method according to any of the preceding claims, wherein the element (40) is a throttle valve. [14] Method according to one of the preceding claims, wherein the motor system further comprises a VGT, wherein the VGT is controlled on the basis of the first parameter P1 such that it controls the gas pressure P IC adjusts. [15] Method according to claim 14, wherein the VGT is controlled such that it controls the gas pressure P IC in the direction of a target value P T for gas pressure P IC adjusts. [16] Computer program containing program code which, when executed in a computer, causes the computer to perform the method according to one of the preceding claims. [17] Computer program product comprising a computer-readable medium and a computer program according to claim 16, wherein the computer program is contained on the computer-readable medium. [18] System comprising an internal combustion engine (10) connected to an air intake system and an exhaust system and further mechanically connected to a transmission, the system further comprising: an element (40) arranged in the air intake system and configured to adjust the gas pressure in the air intake system, and a control device connected to the element (40) and configured to control the element (40); characterized by , that the control device includes: a receiving unit designed to receive at least one first parameter P1, which is associated with a gas pressure P IC is located upstream of element (40) in the air intake system, and a control unit designed to control element (40) on the basis of at least one parameter P1. [19] Motor vehicle comprising at least one system according to claim 18.

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