Method for operating an internal combustion engine with an exhaust gas turbocharger

Abstract

Method for operating an internal combustion engine (2) with an exhaust gas turbocharger (3), wherein the internal combustion engine (2) has an engine block (11) with a flowable intake volume (12) and a flowable exhaust gas volume (13), wherein the intake volume (12) is connected to an intake manifold (14) of the internal combustion engine (2) in a flowable manner, and the exhaust gas volume (13) is connected to an exhaust tract (15) of the internal combustion engine (2) in a flowable manner, and wherein a compressor (4) of the exhaust gas turbocharger (3) is received in the intake manifold (14) in a flowable manner, and an exhaust gas turbine (5) of the exhaust gas turbocharger (3) is received in the exhaust tract (15) in a flowable manner, and wherein a throttle valve (10) is arranged in the intake manifold (14) downstream of the compressor (4), and wherein the exhaust gas turbocharger (3) has a boost pressure control unit (7), and wherein the internal combustion engine (3) in is operable in a pre-tensioned operation,where in pre-charged operation a boost pressure (p, L ) upstream of the throttle valve (10) deviates from an intake manifold pressure (ps) downstream of the throttle valve (10), whereby in pre-tensioned operation the boost pressure (p L ) is greater than the intake manifold pressure (ps), and where the intake manifold pressure (ps) is determined using a target intake manifold pressure (p Ssoll ) and the boost pressure (p L ) using a target boost pressure (p Lsoll ) are set, characterized in that the pre-tensioned operation only occurs when a pressure between the target suction manifold pressure (p) is reached. Ssoll ) and an output boost pressure (p) determined based on a driver request LA ) is activated by the pressure ratio formed, where the pressure ratio is a minimum pressure ratio (V) of the target suction manifold pressure (p). Ssoll ) to a difference between an unthrottled point (UGP) and a safety factor.

Description

[0001] The invention relates to a method for operating an internal combustion engine with an exhaust gas turbocharger according to the preamble of claim 1.

[0002] It is generally known that an exhaust gas turbocharger is used to operate an internal combustion engine efficiently. The turbocharger increases the boost pressure in the engine's cylinders to boost power output. It is driven by exhaust gas from the engine, but can also be electrically powered.

[0003] Particularly when using an internal combustion engine in a motor vehicle, rapid or frequent load changes of the engine may be necessary. This involves changes to various parameters of the engine, one of which is the boost pressure. For smooth power delivery, it is crucial that the boost pressure of the exhaust gas turbocharger converts to a predetermined boost pressure as quickly as possible and without overshoot.

[0004] To ensure that a potentially high boost pressure for the highest possible torque from the internal combustion engine is available quickly and with minimal delay, the engine can be operated in a so-called pre-charged mode. Pre-charged operation refers to an operation of the internal combustion engine in which the boost pressure actually generated by the exhaust gas turbocharger is greater than the pressure in the intake manifold of the engine. This means that at a throttle valve located between the compressor and the intake manifold, a pressure ratio exists in which the pressure before the throttle valve (the boost pressure) is greater than the pressure after the throttle valve (the intake manifold pressure).

[0005] When boost pressure builds up for an operating point during pre-charged operation, this can lead to unusual driving behavior. This is because, especially at high engine speeds and pressure levels, very steep boost pressure gradients occur. The throttle valve is therefore sometimes unable to regulate the intake manifold pressure to the desired value under these steep boost pressure gradients. Furthermore, rapid throttle valve closure during boost pressure buildup creates pressure build-up effects, which can manifest as further deviations or pressure fluctuations. This is because the control units involved in the corresponding regulation – a so-called charge control unit for positioning the throttle valve and a boost pressure control unit for regulating the boost pressure – can oscillate against each other.

[0006] Patent DE 4324868 C2 discloses a method for controlling the boost pressure in an internal combustion engine with an exhaust gas turbocharger.

[0007] Patent DE 10 2008 014 671 B4 describes a control device for an internal combustion engine with an exhaust gas turbocharger, which helps to avoid or suppress the occurrence of a pumping state of the exhaust gas turbocharger, among other things by changing the boost pressure.

[0008] German patent application DE 10 2017 110 140 A1 discloses a method for controlling the boost pressure of a multi-stage charging system comprising an exhaust gas turbocharger and an upstream electric compressor.

[0009] German patent application DE 196 08 630 A1 discloses a method for controlling the boost pressure of a turbocharged internal combustion engine, whereby a target boost pressure is calculated as the sum of a target intake manifold pressure and a throttle differential pressure. The differential pressure depends on an operating point of the internal combustion engine and is multiplied by a driving-style-specific factor. A higher differential pressure is set for dynamic driving.

[0010] Patent application US 2010 / 0154741 A1 discloses a method for an internal combustion engine with an exhaust gas turbocharger, wherein a throttle valve located downstream of a compressor of the exhaust gas turbocharger is set either to the fully open position or, to adjust the intake manifold pressure, to a more closed position. The system switches between the two modes depending on the actual pressure differential across the throttle valve.

[0011] US patent 6,161,384 A discloses a method for an exhaust gas turbocharged internal combustion engine, wherein a predetermined differential pressure across a throttle valve is achieved by adjusting a wastegate of the exhaust gas turbocharger. This results in a cascade-like control process, whereby torque is set using the throttle valve position, and boost pressure is adjusted using the exhaust gas turbocharger to achieve the desired pressure differential.

[0012] The object of the present invention is to provide a method for operating an internal combustion engine with an exhaust gas turbocharger, in particular in a pre-charged operation, with the help of which a comfortable driving operation of a motor vehicle having the internal combustion engine can be realized.

[0013] The problem is solved according to the invention by a method for operating an internal combustion engine with an exhaust gas turbocharger having the features of claim 1. A further method according to the invention is specified in claim 4. Advantageous embodiments with expedient and non-trivial further developments of the invention are specified in the respective dependent claims.

[0014] A method according to the invention for operating an internal combustion engine with an exhaust gas turbocharger, wherein the internal combustion engine has an engine block with a flowable intake volume and a flowable exhaust gas volume, wherein the intake volume is connected to an intake manifold of the internal combustion engine, and the exhaust gas volume is connected to an exhaust tract of the internal combustion engine, and wherein a compressor of the exhaust gas turbocharger is received in the intake manifold, and an exhaust gas turbine of the exhaust gas turbocharger is received in the exhaust tract, and wherein a throttle valve is arranged in the intake manifold downstream of the compressor, and wherein the exhaust gas turbocharger has a boost pressure control unit, and wherein the internal combustion engine can be operated in a pre-charged state.wherein, in pre-charged operation, the boost pressure upstream of the throttle valve differs from the intake manifold pressure downstream of the throttle valve, wherein, in pre-charged operation, the boost pressure is greater than the intake manifold pressure, and wherein the intake manifold pressure and the boost pressure are set using a target intake manifold pressure. According to the invention, pre-charged operation is only activated when a pressure ratio is reached between the target intake manifold pressure and an initial boost pressure determined based on a driver request, wherein the pressure ratio is a minimum pressure ratio of the target intake manifold pressure to a difference between an unthrottled point and a safety factor.

[0015] The control systems have different actuation qualities and speeds, which is why simultaneous operation of both systems—the boost pressure control system and the throttle valve control system—can lead to oscillations within the overall system. This is particularly true in the unrestricted operating range of the throttle valve, as the valve cannot be positioned precisely in this range. To prevent both control systems from being active in this unrestricted operating range, the target boost pressure is reduced to a maximum of the target intake manifold pressure until the difference between the requested boost pressure and the target intake manifold pressure is sufficiently large that the throttle valve no longer needs to operate close to an unrestricted operating point.

[0016] This unthrottled point, whose value is preferably assumed to be 0.98, and further preferably a value of 0.96 of the difference between the unthrottled point and the safety factor with a value of 0.02, successfully leads to an avoidance or at least a significant reduction of oscillation of the control loops, so that the throttle valve can be easily adjusted to bring about a change in the pressure ratio.

[0017] In principle, closing the throttle valve causes a build-up of boost pressure. Simultaneously, the boost pressure and the behavior of the boost pressure control unit determine how much the throttle valve needs to be regulated. The boost pressure control unit, through the concurrent adjustment of a so-called variable turbine geometry or a wastegate valve, influences the exhaust back pressure at a turbine wheel of the exhaust gas turbine, and thus the intake manifold pressure required for this operating point. This means that oscillations of the control units can occur, which can be avoided with the proposed method.

[0018] Another method according to the invention for operating an internal combustion engine with an exhaust gas turbocharger, wherein the internal combustion engine has an engine block with a flowable intake volume and a flowable exhaust gas volume, wherein the intake volume is connected to an intake manifold of the internal combustion engine, and the exhaust gas volume is connected to an exhaust tract of the internal combustion engine, and wherein a compressor of the exhaust gas turbocharger is received in the intake manifold, and an exhaust gas turbine of the exhaust gas turbocharger is received in the exhaust tract, and wherein a throttle valve is arranged in the intake manifold downstream of the compressor, and wherein the exhaust gas turbocharger has a boost pressure control unit, and wherein the internal combustion engine can be operated in a pre-charged mode.wherein in pre-charged operation a boost pressure upstream of the throttle valve deviates from an intake manifold pressure downstream of the throttle valve, wherein in pre-charged operation the boost pressure is greater than the intake manifold pressure, and wherein the intake manifold pressure is set using a target intake manifold pressure and the boost pressure is set using a target boost pressure, is characterized in that the pre-charged operation is only activated when a difference is reached between the target intake manifold pressure and an initial boost pressure determined based on a driver request, wherein the target boost pressure is first adjusted to a value lower than the target intake manifold pressure up to a predetermined control point, in a second step it is adjusted to the target intake manifold pressure, and in a third step it is held at this level until a target point is reached, and in a fourth step it is adjusted to the predetermined target value.which is greater than a specified target intake manifold pressure, is regulated.

[0019] Further advantages, features, and details of the invention will become apparent from the following description of preferred embodiments and from the drawings. The features and combinations of features mentioned above in the description, as well as those mentioned below in the figure description and / or shown in the figures alone, can be used not only in the combinations specified, but also in other combinations or individually, without departing from the scope of the invention. The figures show: Fig. 1. In a schematic diagram, a drive train with an internal combustion engine of a motor vehicle, Fig. 2 in a pressure-time diagram a curve of a target boost pressure, a boost pressure, a target intake manifold pressure, an intake manifold pressure set with a method according to the invention according to a first embodiment based on an initial boost pressure, and Fig. 3 in a pressure-time diagram the course of the target boost pressure, the boost pressure, the target intake manifold pressure, the intake manifold pressure set with the inventive method according to a second embodiment based on the initial boost pressure.

[0020] In Fig. Figure 1 illustrates a powertrain 1 of a motor vehicle comprising an internal combustion engine 2 with an exhaust gas turbocharger 3 in a schematic diagram. The exhaust gas turbocharger 3 has a compressor 4 and an exhaust gas turbine 5, wherein an impeller of the compressor 4 (not shown) is non-rotatably connected to an impeller of the exhaust gas turbine 5 (not shown) by means of a shaft 6.

[0021] Air is drawn in by compressor 4, compressed in compressor 4, and, possibly cooled, supplied to internal combustion engine 2. Fuel is also supplied to internal combustion engine 2, which is combusted with the air in the engine. The resulting exhaust gas is fed to exhaust turbine 5, setting the turbine's impeller in motion. This rotation, in turn, drives the impeller of compressor 4 via shaft 6, thus also setting the compressor 4 in motion.

[0022] The internal combustion engine 2 has an engine block 11 with a flowable intake volume 12 and a flowable exhaust volume 13. The intake volume 12, which can be designed, for example, in the form of an air collector, is connected to an intake manifold 14 of the internal combustion engine 2. The exhaust volume 13, which is usually designed in the form of an exhaust manifold, is connected to an exhaust tract 15 of the internal combustion engine 2.

[0023] The compressor 4 is mounted in the intake manifold 14 so that the air it draws in and compresses can be supplied to the internal combustion engine 2. The exhaust turbine 5 is mounted in the exhaust manifold 15 so that the exhaust gas expelled from the internal combustion engine 2 can be supplied to the exhaust turbine 5 via the exhaust manifold 15 to operate the compressor 4.

[0024] Downstream of the compressor 4, a throttle valve 10 is arranged in the intake manifold 14 to regulate the amount of air supplied to the internal combustion engine 2 at a specific intake manifold pressure p. s .

[0025] Furthermore, the exhaust gas turbocharger 3 has a boost pressure control unit 7, with the help of which the operation of the exhaust gas turbocharger 3 and thus a boost pressure p provided by the compressor 4 is controlled. LThe boost pressure control unit 7, which has conventional control elements and sensors operatively connected to these elements, is operatively connected to a control device of the exhaust gas turbocharger 3 (not shown in detail). This control device can be an adjustable guide vane or a wastegate valve located in the exhaust gas turbocharger 3, which influences the amount of exhaust gas acting on the impeller of the exhaust gas turbine 5. Alternatively, the exhaust gas turbocharger 3 could also have an electric drive that, with the aid of the boost pressure control unit 7, acts on the shaft 6 and thus on the operation of the compressor 4.

[0026] The internal combustion engine 3 can be operated in a so-called pre-charged mode, whereby in pre-charged mode the boost pressure p L upstream of the throttle valve 10 deviates from the intake manifold pressure ps downstream of the throttle valve 10, in particular where the boost pressure p is in pre-tensioned operation Lis greater than the intake manifold pressure (ps). In other words, a pressure differential is formed at the throttle valve 10 during pre-tensioned operation.

[0027] The regulation of the boost pressure p L requires a set target boost pressure p LSoll , which can be provided, for example, by means of a control unit 8 of the internal combustion engine 2. The control unit 8 can additionally be configured to record parameters of the internal combustion engine 2, such as an intake air mass or a lambda value downstream of the internal combustion engine 2, and to control the internal combustion engine 2 and influence its operating state by means of actuators. The actuators can, in particular, include a fuel injector, a valve adjustment, or an ignition system.

[0028] This means that the desired boost pressure p Lof the exhaust gas turbocharger 3 with the aid of the boost pressure control unit 7, which sets the target boost pressure p LSoll provides, can be regulated.

[0029] The boost pressure control unit 7 can be integrated with the control unit 8. It is proposed to set the target boost pressure p. LSoll under certain circumstances to manipulate in order to achieve an improved time course of the boost pressure p L regarding the target boost pressure p LSoll to achieve this. In particular, the boost pressure p should be increased. L quickly reaching the target boost pressure p LSoll approximate, but in particular do not exceed, and exhibit the most harmonious progression possible.

[0030] The boost pressure control unit 7 could, for example, be connected to the control and monitoring unit 8 via an interface in order to determine the target boost pressure p. LSollto receive. Another interface could be provided to measure the boost pressure p L to scan the exhaust gas turbocharger 3. Such scanning and control devices are generally known, so there is no need to discuss them in more detail here.

[0031] In Fig. 2 in a pressure p-time t-diagram represent the course of the target boost pressure p. LSoll , which is marked with a bold solid line, of the boost pressure p achieved with it L , which is marked with a thin solid line, of the target intake manifold pressure p Ssoll , which is marked with a bold dashed line, and the resulting intake manifold pressure p s , which is marked with a thin dotted line, illustrates which were determined using a method according to a first embodiment according to the invention.

[0032] The method according to the invention determines the pre-tensioned operation based on an initial boost pressure p determined on the basis of a driver request. LA This initial boost pressure p LA is marked with a thin dashed line in Fig. 2 entered. The initial boost pressure p LA This results in a torque with a specific target value of the boost pressure p. LsoııZ However, since no or minimal oscillations are caused between the two control loops, the control loop for the boost pressure of the exhaust gas turbocharger 3 and the control loop for the throttle valve 10, it is advantageous to only initiate pre-tensioned operation when a value between the target intake manifold pressure p is reached. Ssoll and the output boost pressure p determined based on the driver request LAto activate the designed minimum pressure ratio V. This minimum pressure ratio V has a safety margin, in particular from a so-called unthrottled point UGP, so that the preload can be regulated without vibration or at least almost without vibration.

[0033] The unrestricted point (UGP) describes a ratio of the target intake manifold pressure p. Ssoll to the initial boost pressure p LAThe unthrottled point (UGP) with a value of at least 0.98 represents a critical activation of the preload. Therefore, to achieve reliably vibration-free, or at least virtually vibration-free, control, it is advantageous to set the safety margin at a value of 0.02. For example, the unthrottled point (UGP) has a value of 0.98 and the safety margin has a value of 0.02, resulting in a difference of 0.96. This would, for example, lead to reliably vibration-free, or at least virtually vibration-free, preload at an output boost pressure p, assuming a target intake manifold pressure of 2.0 bar as requested by the driver. LA with a value of 2.04 bar. Or in other words, the calculated initial boost pressure p, which runs "in the background", indicates LA When the pressure reaches 2.04 bar, the preload is "ramped in". This occurs at the target time tz, which is in Fig. The example shown in point 2 is achieved.

[0034] Thus, the target boost pressure p LSoll starting from the target intake manifold pressure p Ssoll and the output boost pressure p LA regulated with the condition that - provided the output boost pressure p LA is greater than or at least equal to the quotient of the target intake manifold pressure p Ssoll and the unrestricted point UGP minus the safety margin, the target boost pressure p Ssoll the initial boost pressure p LA corresponds, or - provided the output boost pressure p LA is smaller than the quotient of the target intake manifold pressure p Ssoll and the unrestricted point UGP minus the safety margin, the target boost pressure p LSoll the target intake manifold pressure p Ssoll corresponds.

[0035] Once the minimum pressure ratio V is reached, the target boost pressure P is set. Lsoll on its target value p LsollZ, where the regulation of the boost pressure p L is brought about, which corresponds to the target boost pressure p Lsoll until the target value p is reached LsollZ This follows. In other words, this means that only when the minimum pressure ratio V is reached will the target value p be adjusted. LsollZ of the target boost pressure p Lsoll is ramped into the desired pre-tensioned operation.

[0036] When constructing ramps, a gradient limit for the ramp slope must also be considered. Furthermore, time-based debouncing may need to be taken into account.

[0037] In Fig. Figure 3 in another pressure-time diagram shows the curve of the target boost pressure p. Lsoll , of the boost pressure p L , of the target intake manifold pressure p Ssoll , of the intake manifold pressure ps and of the outlet boost pressure p LA illustrated which are adjusted using the inventive method according to a second embodiment.

[0038] In the inventive method according to the second embodiment, starting from the initial boost pressure p LA , which is specified by the driver request, and which also in the second embodiment of the method according to the invention is used in the background to adjust the target boost pressure p Lsoll and the target intake manifold pressure p Ssoll The target boost pressure p runs along, but is not transmitted to the control unit of the exhaust gas turbocharger 3. LSoll to a level of the target intake manifold pressure p Ssoll The boost pressure is regulated and maintained at this level until a target time tz. Then the boost pressure p is adjusted. L with the help of the target boost pressure p LSoll to a target value p that causes the preload LsollZ raised.

[0039] Before reaching the target intake manifold pressure p SsollTo reliably prevent vibrations, a rounded increase in the target boost pressure p is achieved using a PT1 element. Lsoll , which determines the boost pressure p L This follows. In other words, that means the target boost pressure p LSoll over a period of time from the request of the output boost pressure p LA until a target time t is reached R , which lies before the target time tz, below the target intake manifold pressure p Ssoll is held.

[0040] Or in other words, the pre-tensioned operation only begins when a pressure between the target intake manifold pressure p is reached. Ssoll and the output boost pressure p determined based on a driver request LA trained difference activated, whereby - the target boost pressure p Lsoll in a first step up to a predetermined control time t R to a value less than the target intake manifold pressure p Ssoll is regulated, - in a second step to the target intake manifold pressure p Ssoll is regulated, - in a third step, this level is maintained until a target time tz is reached, thus for a certain predetermined duration, and - in a fourth step to the specified target value p LsollZ , which is greater than a specified target intake manifold pressure p Ssoll ,is regulated.

[0041] The target time tz, which marks the start of the induced preload, depends on the control loops and their oscillation behavior, and must therefore be determined in relation to them. The control time t R depends on the target time and the duration of the adjustment to the target intake manifold pressure P Ssoll .

[0042] In other words, this means that with the aid of the inventive method according to the second embodiment, the boost pressure p Lwith the help of the target boost pressure p Lsoll It features a gentle and steadily decreasing increase to achieve a particularly comfortable driving experience. In particular, the rounded increase of the target boost pressure p LSoll continuously trained.

[0043] In particular, the rounded increase runs almost tangentially to the target intake manifold pressure p. Ssoll into. After reaching the target intake manifold pressure p Ssoll The target boost pressure p Lsoll with a defined gradient to its target value p LsollZ raised, which increases the boost pressure p L follows until he reaches the target value p LsollZ has also achieved.

[0044] The adjustment of the target boost pressure p LSoll can be carried out via a filling control unit comprising the throttle valve 10, or it can be carried out via the boost pressure control unit 7. Reference symbol list 1 Powertrain 2 Internal combustion engine 3 exhaust gas turbochargers 4 compressors 5 Exhaust gas turbine 6 wave 7 Boost pressure control unit 8 Control and regulation unit 9 Communications Management 10 Throttle valve 11 Engine block 12 Intake volume 13 Exhaust gas volume 14 Intake manifold 15 Exhaust system V Minimum pressure ratio UGP Unthrottled Point p print PS Intake manifold pressure p L Boost pressure p LA Output boost pressure p Ssoll Target intake manifold pressure P Lsoll Target boost pressure p LsollZ Target value t time t R Regular time target time

Claims

[1] Method for operating an internal combustion engine (2) with an exhaust gas turbocharger (3), wherein the internal combustion engine (2) has an engine block (11) with a flowable intake volume (12) and a flowable exhaust gas volume (13), wherein the intake volume (12) is connected to an intake manifold (14) of the internal combustion engine (2) in a flowable manner, and the exhaust gas volume (13) is connected to an exhaust tract (15) of the internal combustion engine (2) in a flowable manner, and wherein a compressor (4) of the exhaust gas turbocharger (3) is received in the intake manifold (14) in a flowable manner, and an exhaust gas turbine (5) of the exhaust gas turbocharger (3) is received in the exhaust tract (15) in a flowable manner, and wherein a throttle valve (10) is arranged downstream of the compressor (4) in the intake manifold (14), and wherein the exhaust gas turbocharger (3) has a boost pressure control unit (7), and wherein the internal combustion engine (3) is operable in a pre-tensioned operation,where in pre-charged operation a boost pressure (p, L ) upstream of the throttle valve (10) deviates from an intake manifold pressure (ps) downstream of the throttle valve (10), whereby in pre-tensioned operation the boost pressure (p L ) is greater than the intake manifold pressure (ps), and where the intake manifold pressure (ps) is determined using a target intake manifold pressure (p Ssoll ) and the boost pressure (p L ) using a target boost pressure (p Lsoll ) will be set up, characterized by that the pre-tensioned operation only occurs when a pressure between the target intake manifold pressure (p) is reached Ssoll ) and an output boost pressure (p) determined based on a driver request LA ) is activated by the pressure ratio formed, where the pressure ratio is a minimum pressure ratio (V) of the target suction manifold pressure (p). Ssoll ) to a difference between an unthrottled point (UGP) and a safety factor. [2] Method according to claim 1, characterized by, that the unthrottled point (UGP) has a value of 0.98, and that the safety factor has a value of 0.

02. [3] Method according to any one of the preceding claims, characterized by , that after reaching the minimum pressure ratio (V), the target boost pressure (p) is regulated. Lsoll ) to its target value (p LsollZ ). [4] Method for operating an internal combustion engine (2) with an exhaust gas turbocharger (3), wherein the internal combustion engine (2) has an engine block (11) with a flowable intake volume (12) and a flowable exhaust gas volume (13), wherein the intake volume (12) is connected to an intake manifold (14) of the internal combustion engine (2) in a flowable manner, and the exhaust gas volume (13) is connected to an exhaust tract (15) of the internal combustion engine (2) in a flowable manner, and wherein a compressor (4) of the exhaust gas turbocharger (3) is received in the intake manifold (14) in a flowable manner, and an exhaust gas turbine (5) of the exhaust gas turbocharger (3) is received in the exhaust tract (15) in a flowable manner, and wherein a throttle valve (10) is arranged downstream of the compressor (4) in the intake manifold (14), and wherein the exhaust gas turbocharger (3) has a boost pressure control unit (7), and wherein the internal combustion engine (3) is operable in a pre-tensioned operation,where in pre-charged operation a boost pressure (p, L ) upstream of the throttle valve (10) deviates from an intake manifold pressure (ps) downstream of the throttle valve (10), whereby in pre-tensioned operation the boost pressure (p L ) is greater than the intake manifold pressure (ps), and where the intake manifold pressure (ps) is determined using a target intake manifold pressure (p Ssoll ) and the boost pressure (p L ) using a target boost pressure (p Lsoll ) will be set up, characterized by that the pre-tensioned operation only occurs when a pressure between the target intake manifold pressure (p) is reached Ssoll ) and an output boost pressure (p) determined based on a driver request LA ) formed difference is activated, whereby the target boost pressure (p Lsoll ) in a first step up to a predetermined control time (t R ) to a value less than the target intake manifold pressure (p Ssoll ) is adjusted, in a second step to the target intake manifold pressure (p Ssoll) is adjusted, and in a third step is maintained at this level until a target time (tz) is reached, and in a fourth step is adjusted to the specified target value (p). LsollZ ), which is greater than a specified target intake manifold pressure (p Ssoll ), is regulated. [5] Method according to claim 4, characterized by , that upon reaching the target time (t R ) a regulation is implemented to bring about a rounded increase up to the target time (tz). [6] Method according to claim 5, characterized by , that the rounded increase of the target boost pressure (p Lsoll ) is continuously trained. [7] Method according to claim 5 or 6, characterized by , that the rounded increase is achieved with the help of a PT1 element.

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