Method for controlling an internal combustion engine with an engine and an exhaust gas turbocharging group and with a transmission, control device and internal combustion engine

Abstract

Method for controlling a drive comprising a transmission (500) and an internal combustion engine (1000) with an engine (200), an exhaust gas turbocharging group (100) which has a basic exhaust gas turbocharger (110) and a switching exhaust gas turbocharger (120) for the engine (200), wherein - the switching exhaust gas turbocharger (120) is designed to be operated in addition to the basic exhaust gas turbocharger (110) and with the transmission (500) having a number of gear stages, for the controlled switching of the transmission (500) and / or for the controlled operation of the engine (200) and / or a controlled switching of the register charging of the internal combustion engine (1000), wherein - one of the number of gear stages of the transmission (500) is switched depending on a limit value of a speed parameter, - an indicative vitality signal of a vitality reserve of the internal combustion engine (1000) is signalled, wherein the vitality signal is determined as a function of at least two operating parameters influencing the vitality reserve of the internal combustion engine (1000), namely a first operating parameter of the engine (200) and a second operating parameter of the exhaust gas turbocharging group (100), wherein the two operating parameters influencing the vitality reserve of the internal combustion engine (1000) are an engine speed (nMOT) and a charge air pressure (pLL), and - a downshift limit of the speed parameter for one of the number of gear steps, depending on the signalled vitality signal, is maintained or reduced to a deceleration limit that is below the downshift limit, and the reduction of the downshift limit to the deceleration limit is made for a third or higher gear step and is limited to the third or higher gear step, whereby - one of the number of gear steps of the gearbox (500) is signalled, and - the downshift limit and the deceleration limit are dependent on and specific to one of the number of gear ratios of the transmission.

Description

The invention relates to a method for controlling an internal combustion engine having an engine, an exhaust gas turbo-charging group, which has a basic exhaust gas turbocharger and a shift exhaust gas turbocharger for the engine, and having a transmission with a number of gear stages, in particular for controlled shifting of the transmission and / or for controlled operation of the engine and / or a controlled shifting of the register charging of the internal combustion engine. In particular, the basic exhaust gas turbocharger has a basic compressor for charge air and a basic turbine for exhaust gas, wherein the basic turbine is designed to drive the basic compressor. In particular, the switching exhaust gas turbocharger has a switching compressor for charge air and a switching turbine for exhaust gas, wherein the switching turbine is designed to drive the switching compressor. The invention also relates to a control device and an internal combustion engine. The invention also relates to a control device and an internal combustion engine.In internal combustion engines, ideally, the aim is to achieve a torque characteristic curve that is as uniform and high as possible, starting from the idling speed up to high rotational speeds. One means for increasing the torque, in particular in the rotational speed range below a nominal rotational speed, is to convey more air into the combustion chamber using exhaust gas turbochargers or mechanical superchargers. However, these systems have a pronounced torque weakness in the low speed range, for example in the range from about 1500 min -1 to 2000 min -1. In addition, limitations in the dynamics of the engine occur during transient driving operation, since during acceleration processes, the rotor of the turbocharger must first be accelerated in order to provide an air mass flow corresponding to the setpoint value. The torque weakness can still be noticeable, in particular when shifting a shift turbocharger, even according to the method mentioned at the beginning.A wide variety of methods are known from the prior art for controlling a register charging of an internal combustion engine.DE 103 08 075 B4 discloses a method for controlling exhaust gas turbochargers of an internal combustion engine according to the type mentioned at the beginning, which is provided with a first permanently operated exhaust gas turbocharger and a second switchable exhaust gas turbocharger and with a bypass line for bypassing the exhaust gas flow on the first exhaust gas turbocharger. A first and a second wastegate are provided for controlling an exhaust gas flow, wherein the first wastegate is activated when the rotational speed of the first exhaust gas turbocharger exceeds a limit value. A check is then made as to whether an operating variable of the internal combustion engine-for example the charge air pressure or the exhaust gas volume flow-exceeds a limit value. If this is the case, the second wastegate is activated. As a result, the second exhaust gas turbocharger is put into idle operation. A check is then made as to whether the rotational speed of the second exhaust gas turbocharger exceeds a limit value. If this is the case, the second exhaust gas turbocharger is completely activated. Thereafter, both wastegates are closed.This method for controlling a register charging already represents a good approach for improving a response behavior of a register charging for an internal combustion engine, in particular for a transient driving operation and at low engine speeds. Nevertheless, here too, during acceleration processes, the rotor of the shifting exhaust gas turbocharger must first be accelerated in order to provide a charge air mass flow suitable for the further supercharging of the internal combustion engine. The principle known from the prior art of threshold value control, i.e. first of all to open a switching device for exhaust gas and then to open it for charge air when the switching exhaust gas turbocharger has reached a permanently or variably predefined rotational speed-is, however, merely a compromise which has to make do with consideration of operating states of other components of the internal combustion engine-in particular of the engine and of the exhaust gas turbo-supercharging group. For example, when driving downhill and at a very high engine speed, the situation may arise that, despite a comparatively low engine torque, the switching exhaust gas turbocharger is nevertheless activated. Even if the operation of the shift exhaust gas turbocharger under air compression took place only above a predetermined rotational speed, then in this situation a power dip, i.e. a drop in the rotational speed of the shift exhaust gas turbocharger at any rate and a drop in the charge pressure would nevertheless have to be expected.Already at idling speed, the torque of diesel engines reaches relatively high torques with 50% of the maximum value. In some road vehicles, the torque curve is limited by control electronics, which in critical operating cases decrease the injected fuel quantity and thus the torque, in order to protect the drive train (transmission, final drive, drive shafts) from overloading or, for cost reasons, to retain a greater number of identical parts with similar vehicle models with the existing design of the drive train. The control electronics of the motor controller are networked with further controllers. Relevant for the drive of the vehicle are, in particular, the controls of automated transmissions or automatic transmissions, the brake system, the driving stability control, but also of the air conditioning system. The interfaces for the drive train-related communication are integrated in the torque structure in the diesel engine control unit. Within the torque structure, the required engine torque is calculated from all torque requests and the active limits. At the output of the torque structure, the engine torque of the diesel engine to be set is converted into one or more injection quantities and the respectively associated injection starts.US 5 351 486 A discloses a controller capable of shortening the startup time for a shift exhaust turbocharger when the instantaneous engine speed is low, so that the torque weakness in switching from a supercharger to a dual supercharger operation is reduced. During high accelerations at high engine speeds, an exhaust switching valve opens at once. In addition, the reference of the engine speed and the charge air mass for shifting the shifting exhaust gas turbocharger is varied in accordance with a gear stage shift position of the transmission, so that improved dual-charger operation is achieved.It is desirable to achieve improved exhaust turbo-supercharger group and / or transmission shift performance. In particular, it is desirable to provide an even further improved method of controlling a transmission of an internal combustion engine having an engine and an exhaust turbo-supercharger group and a transmission.In particular, it is desirable to provide an even further improved method for controlling register charging of an internal combustion engine having an engine and an exhaust turbo-charger group. In particular, during idling operation and / or during load operation (i.e. under air compression), an improved shifting behavior of the shifting exhaust gas turbocharger is to be achieved.Overall, there is a problem with highly charged motors which are charged, in particular, with a register charging system when shifting operations have to be carried out. These not only influence the driving behavior, possibly disadvantageously, but can also lead to a torque weakness of the type explained at the beginning. The result is a comparatively poor engine connection behavior during supercharger and / or transmission shift processes.DE 199 28 510 A1 discloses a control system for downshifting an automatic transmission in a motor vehicle during a coasting phase, wherein an electronic transmission control determines its rotational speed gradient from a measured transmission output rotational speed. The shift sequences are then implemented in such a way that a suitable gear is present for reacceleration of the vehicle from slowed travel or from standstill.DE 44 197 53 A1 provides a control device having the capability of controlling the operation such that the gear shift operation is suitable for the pedal operation by the driver for acceleration and deceleration. The pedal operation is monitored at the acceleration under deceleration to compensate for a predetermined displacement per unit time of the accelerator pedal so that unnatural pedal operation by the driver can be avoided.DE 43 252 96 A1 discloses a control system for shifting an automatic transmission using fuzzy logic techniques. These are expanded in a closed control loop in which the fictitious variable "desired performance" and the variable "driving style" are converted into a physical variable.DE 41 205 66 A1 discloses a method for controlling an electrohydraulically actuated transmission of a vehicle equipped with an internal combustion engine with a prevention of upshifts or a reduction in the transmission ratio.DE 41 206 03 A1 provides an upshift prevention with rapid removal of the accelerator pedal in overrun operation. The upshift prevention is canceled if a curve is traversed after a time period has elapsed after train operation is detected. When the upshift prevention is ended, the gear stage is adapted stepwise to the specification from the shift characteristic map.Document EP 1 268 232 B1 relates to a method for controlling an automatic transmission depending on an operating mode of an internal combustion engine.Document US 5 341 295 A describes a control unit for an automatic transmission of a vehicle.None of the aforementioned transmission controls provides communication between the individual components of an internal combustion engine, and it can be seen in particular that there is no sufficient communication between the engine, the transmission and / or a turbo-supercharging group. In particular, transmission shift processes take place without taking into account engine characteristics. The consequence is that driving--especially in the case of highly charged motors--under high load causes frequent shifting operations, which can also occur as pendulum shifts. Especially in heavy commercial vehicles and military vehicles, in which low-displacement engines and automatic transmissions are used, this represents a considerable problem, since the load requirement due to pendulum shifts may not be reliably fulfilled.It is desirable to improve the shift operation of the transmission and / or the turbo-supercharger group by better communication with the engine of the internal combustion engine.At this point, the invention starts, the object of which is to specify an improved method and a device by means of which improved control of a transmission and / or a turbo-supercharging group of an internal combustion engine having an engine and an exhaust-gas turbo-supercharging group and a transmission is possible, in particular an improvement in the shifting behavior of the transmission and / or of the turbo-supercharging group.With regard to the method, the object is achieved by the invention with a method of the type mentioned at the beginning, in which the features of the characterizing part of claim 1 are also provided according to the invention.With regard to the apparatus, the object is achieved by the invention with a control device of claim 15.With regard to the device, the object is also achieved by the invention with an internal combustion engine of claim 16.In a method for controlling an internal combustion engine having an engine, an exhaust gas turbo-supercharging group which has a basic exhaust gas turbocharger and a shift exhaust gas turbocharger for the engine, wherein the shift exhaust gas turbocharger is designed to be operated in addition to the basic exhaust gas turbocharger, and having a transmission having a number of gear stages, it is provided that a gear stage of the transmission is shifted as a function of a limit value of a rotational speed parameter. The invention is based on the consideration that the problem of pendulum shifts in a transmission and also the possibly poor engine connection behavior in transmission shift processes in high load operation in highly charged and low displacement engines arises inter alia in that a transmission upshift characteristic curve-i.e. a characteristic curve for controlling the transition from a low gear stage to a higher gear stage-and a transmission downshift characteristic curve-i.e. a characteristic curve for transitioning from a higher gear stage to a lower gear stage-are comparatively close to one another. Such characteristic curves are regularly stored in the transmission control unit and define the shifting of a gear stage of the transmission depending on a limit value of a rotational speed parameter, in particular an engine speed and / or a transmission rotational speed. Although an engine control unit has fundamentally access to the transmission control unit, communication between the transmission control unit and the engine control unit can still be improved in order to enable improved engine connection behavior, in particular during shifting of the transmission and / or during supercharger shifting.The invention has recognized that it is advantageous if a vitality signal indicating the vitality reserve of the internal combustion engine is signaled, in particular is signaled on the engine side. The invention provides that a downshift limit value of a rotational speed parameter for a gear stage-depending on the vitality signal-is maintained or lowered to a deceleration limit value which is below the downshift limit value. The downshift limit value of the aforementioned type is advantageously influenced on the transmission side.The concept of the invention thus provides a comparatively close combination of an engine control with a transmission control. In particular, a vitality reserve of the internal combustion engine is made known to the transmission control, for example via a data bus, and is taken into account in the characteristic curve for the shifting behavior. The vitality reserve on which the vitality signal is based is determined in particular at the engine and / or at the turbo-charging group, or corresponding operating parameters can be provided at the engine side and / or at the turbo-charging group, for example via data construction.In automatic transmission operation, it is regularly necessary to carry out a shift-down process fundamentally at an early stage; if, for example, sufficient torque is still to be available during hill climbing or other speed-lowering load requirements. The invention has nevertheless recognized that this measure can be unnecessary, for example in the case that the internal combustion engine still has sufficient vitality reserve, in particular the engine and / or the turbo-supercharging group have operating parameters which influence the vitality reserve and are sufficiently high. The concept of the invention enables, in the event that the vitality reserve of the internal combustion engine is displayed, in particular if an operating parameter of the engine and / or of the turbo-supercharging group is above a vitality limit value indicating a sufficient vitality reserve, a shift from a present gear stage to a lower gear stage can be delayed. In particular, a delay can be achieved in that, for example, a shift only takes place at a lower rotational speed of the engine or a lower rotational speed on the transmission side; this consequently leads to a delay in the shift-back process. In this respect, "deceleration" is not necessarily to be understood as being time-dependent, but merely expresses the concept of driving the internal combustion engine in a higher gear stage as long as sufficient vitality values are present. Expressed simply, an engine-side vitality signal is given which reflects the operating state or the performance of the engine and / or the turbo-supercharging group. This vitality signal can be evaluated on the transmission side and a reverse shift of the signal can thus be delayed--in the above sense--if the vital values of the internal combustion engine are still sufficiently good.This measure has the advantage that vitality reserves of the engine are used in an improved manner, which proves to be advantageous in particular in the case of full-load operation. In particular, the measure according to the invention increases a distance between characteristic curves in an internal combustion engine which determine the upshift behavior on the one hand and the downshift behavior on the other hand, in particular at the transmission and / or at the transmission control. The risk of pendulum shifts is thus largely reduced or completely avoided. In particular, this relates to the risk of pendulum shifts of the transmission between a higher and a lower gear stage. In principle, however, the tendency toward pendulum shifts and generally the number of unnecessary shifting operations is reduced; advantageously, the concept leads to an increase in the usable speed band for automatic transmissions.Advantageous refinements of the invention can be gathered from the dependent claims and specify in detail advantageous possibilities for realizing the concept explained above within the scope of the object setting and with regard to further advantages.Pendulum shifts also result in changed supercharger loads, so that in the worst case, pendulum shifts can also occur in a supercharger shift, which can further degrade the situation of engine connection behavior. In a particularly preferred development of the invention, a characteristic curve basis is accordingly proposed which improves the switching behavior of the exhaust gas turbo-supercharging group. Overall, an improved shifting behavior of the transmission and additionally, in particular, of the exhaust gas turbo-supercharging group can be achieved.Preferably, transmission shift points and / or supercharger shift points of the exhaust turbo-supercharging group are made depending on a performance of the engine at each operating point. This results in consideration of the dynamic engine behavior for the shifting action of the transmission and / or a supercharger of the exhaust turbo-supercharger group.In a particularly preferred development, it is provided that in a characteristic curve field for a gear stage shift, two operating parameters are determined which influence the vitality reserve of the internal combustion engine, wherein a first operating parameter is an operating parameter of the engine and a second operating parameter is an operating parameter of the turbo-charging group.Preferably, a first operating parameter influencing the vitality reserve of the internal combustion engine is an engine speed. The second operating parameter that influences the vitality reserve of the internal combustion engine is preferably a supercharging pressure, in particular a charge air pressure. This has the advantageous consequence that if a vitality signal indicates that there is a vitality reserve of the engine, a gear stage shift of the transmission can be delayed or can be shifted to lower vitality values. This may be the case when an engine speed is above a vitality limit value of the engine speed and the supercharging pressure is above a further vitality limit value of the supercharging pressure.An improved shifting behavior of the turbo-supercharger group is preferably achieved by activating the operation of a shifting exhaust-gas turbocharger at idle as a function of the values of a first parameter group of operating parameters, which consists of the operating parameters of a rotational speed of the basic exhaust-gas turbocharger, a rotational speed of the engine and a further load-determining operating parameter of the engine. This is preferably an injection amount of the engine in view of the supercharger switching operation.It has proven particularly useful to take into account an above-mentioned three-dimensional characteristic curve field of vitality signal, rotational speed of the engine and charge pressure for a delayed shifting activity of the transmission and additionally to take into account the mentioned three-dimensional characteristic curve field of a rotational speed of the exhaust gas turbocharger, a rotational speed of the engine and an injection quantity of the engine for the shifting activity of the shift exhaust gas turbocharger. In both three-dimensional characteristic fields, an operating parameter of the internal combustion engine, in particular of the engine and of the turbo-supercharger group, which indicates vitality or load, is taken into account--in the transmission shift part, the supercharging pressure and, in the case of supercharger shift, an injection quantity--in addition to a rotational speed parameter.In particular, it has proven advantageous that a gear stage of the transmission is signaled and a shift-down limit value of a rotational speed parameter for the signaled gear stage is maintained or lowered to a deceleration limit value which is below the shift-down limit value, wherein the shift-down limit value and / or the deceleration limit value are dependent on the gear stage. As a result, a gear stage-specific delayed downshift behavior can be established.In the present case, "delayed downshift behavior" means the effect which is achieved by lowering a downshift limit value to a deceleration limit value. This may include a time delay of the downshift, which, however, does not necessarily occur. This ultimately depends on the respective operating point of the engine taking into account the dynamic engine behavior.Preferably, the shift-back limit value and / or the deceleration limit value of the rotational speed parameter for a gear stage of the transmission is a transmission rotational speed on the transmission side. In principle, an engine speed can also be used. The deceleration limit value is in particular a minimally feasible rotational speed of a gear stage. In other words, a deceleration limit value has proven to be advantageous which is sufficiently below the downshift limit value that, at the minimum feasible rotational speed and the gear stage of the transmission, the torque to be expended just still corresponds to the feasible engine torque; that is, stalling of the engine in the gear stage is just still prevented. This lowering of the shift-down limit value to the deceleration limit value can be accepted in the case of sufficiently high vitality reserves of the engine.In particular, it has proven advantageous that a lowering of the shift-down limit value to a deceleration limit value is carried out only for a third or higher gear stage, i.e. only for a shift-down process from a third to a second gear stage or from a fourth to a third gear stage or from a fifth to a fourth gear stage or from a sixth to a fifth gear stage. The minimum possible engine speed is preferably in the range between 2,400 and 2,900 revolutions per minute.Within the scope of a preferred development, the vitality signal is designed to indicate that a vitality reserve of the motor is either present or not present. For this purpose, the vitality signal is preferably a digital signal having at least two states, a first state indicating that a vitality reserve of the motor is present and a second state indicating that a vitality reserve of the motor is not present. In the context of a further improvement, it is provided that the vitality signal can be evaluated, in particular on the transmission side, by means of 2-bit logic.The 2-bit logic comprises in particular the evaluation states: 0 0 0 switchback enabled (not vital); this also delays (vital) 0 1 switchback even in the event of failure of a data bus; 1 0 signaling is not used; 1 1 signaling is not available.In the case of a 2-bit logic, it can also be taken into account, as mentioned above, in addition to merely displaying a positive or negative vitality signal, that a vitality signal is not available or cannot be used or is not intended. This can also take account of states in manual operation or take account of fault states which must not be neglected.It is preferred that two operating parameters influencing the vitality reserve of the internal combustion engine are signaled from the internal combustion engine, in particular from the engine on the engine side and / or from the turbo-supercharging group, to a data bus. These can be evaluated on the transmission side to generate the vitality signal. In particular, it is provided for this purpose that a three-dimensional characteristic curve field of vitality signal, engine speed and supercharging pressure is stored in an electronic transmission control module.In order not to unnecessarily compromise low torque operating ranges of an engine due to a shift-back deceleration of the aforementioned type, it has proven advantageous that the shift-back deceleration is preferably used in a range of a torque increase or is limited to the range of a torque increase. In particular, it may be provided for this purpose that a downshift delay is permitted in a range of an engine speed above 2,000 U / min, in particular up to 3,100 U / min. In particular, it has proven advantageous that a shift-back delay is permitted in a range of a supercharging pressure between 2 bar and 3.1 bar or is limited to this range of the supercharging pressure. This advantageously ensures that the vitality check fundamentally takes place in a boost pressure range in which it is to be assumed with a comparatively high probability that it leads to a sufficient vitality reserve. Advantageously, areas of the engine or of the turbo-supercharging group which are low in charge pressure are thereby excluded from the outset. Overall, the system for shift-back delay thus becomes more reliable and effective.Preferably, a shift-back delay is implemented by means of a parameter characteristic curve which is a function of an accelerator pedal position as a function of a transmission rotational speed or engine rotational speed on the transmission side. In particular, a downshift delay is permitted even above a lowered parameter characteristic curve characterizing a lowered downshift threshold. In particular, instead of being above a parameter characteristic curve (KD) characterizing a normal shift-down threshold, the decreased parameter characteristic curve (KDO) runs at lower rotational speeds than the normal parameter characteristic curve (KD).A shift-back delay thus preferably takes place only above a lowered parameter characteristic curve characterizing a lowered shift-back threshold, wherein the parameter characteristic curve is a function of an accelerator pedal representation as a function of a transmission speed or engine speed at the transmission end. In other words, the shift-down delay can thereby be limited to certain upper accelerator pedal positions above a certain kick-down point. For example, the lowered parameter characteristic curve can run in an upper rotational speed range above a first minimum accelerator pedal position (e.g. 90%) and the normal parameter characteristic curve can run above a second minimum accelerator pedal position (e.g. 80%), wherein the first minimum accelerator pedal position (90%) is greater than the second minimum accelerator pedal position (80%). This ensures that the desire for a high load demand can also be met for which the concept has proven to be particularly advantageous.Advantageously, a shift from a higher gear stage to a lower gear stage is not delayed-i.e. enabled-when a defect is detected, in particular when a data bus defect and / or sensor defect, in particular for a charge pressure sensor and / or a rotational speed sensor, is detected. In the case of a data bus defect and / or sensor defect or other defect, a preferred development thus provides that a switch-back delay is enabled, i.e. is not used. As a result, occasionally occurring system errors have not been affected by the driving behavior, so that the concept of the development cannot have a disadvantageous effect on the method, in particular in high-load operation.In particular, it is provided that a basic exhaust gas turbocharger has a basic compressor for charge air and a basic turbine for exhaust gas, wherein the basic turbine is designed to drive the basic compressor, and the switching exhaust gas turbocharger has a switching compressor for charge air and a switching turbine for exhaust gas, wherein the switching turbine is designed to drive the switching compressor, and whereinthe switching exhaust gas turbocharger is designed to be operated in addition to the basic exhaust gas turbocharger, wherein:the operation of the basic exhaust gas turbocharger and / or shift exhaust gas turbocharger, in particular of the shift exhaust gas turbocharger, of the exhaust gas turbo-supercharging group is shifted, in particular activated and / or deactivated, as a function of the values of at least one parameter group of at least two operating parameters.The term "switching" in the present case comprises "activating" and --for reverse control direction--also "deactivating".Within the scope of a particularly preferred development, the steps are provided:operating the basic exhaust gas turbocharger at changing rotational speeds (nATL1);detecting a limit value of a first parameter characteristic curve, in particular a limit value rotational speed (GW-nATL1) of the basic exhaust gas turbocharger and / or a limit value rotational speed (GW-nMOT) of the engine;operating the switching exhaust gas turbocharger at idle, with the guidance of exhaust gas via the switching turbine, without the guidance of charge air via the switching compressor;detecting a limit value of a second parameter characteristic curveoperating the shifting exhaust gas turbocharger under air compression with guidance of exhaust gas via the shifting turbine and guidance of charge air via the shifting compressor. The shift first into the idle mode and then into the load mode of the turbo-charger group has proven itself for reducing the torque weakness.The development is based on the consideration that previously known approaches to threshold value regulation-for example for achieving a maximum charging rotational speed or activation of the shifting exhaust gas turbocharger-exhibit basically positive effects only above a limit rotational speed of the shifting exhaust gas turbocharger-for avoiding power dips and / or torque weaknesses in the shifting process from the basic exhaust gas turbocharger to the shifting exhaust gas turbocharger. Nevertheless, the development has recognized that such and other approaches make rigid or very restrictive specifications-even if they operate with characteristic curves or characteristic maps; for example, if only the operating state of the exhaust gas turbocharger to be connected is taken into account in order to regulate the switching behavior. As recognized by the development, current load states and rotational speed states of other components of the internal combustion engine, in particular of the engine and / or of the exhaust gas turbo-supercharging group, are thus ignored, although these may possibly be decisive for a shifting process without a power dip.In the context of a particularly preferred development, it is provided that the basic exhaust gas turbocharger and / or shifting exhaust gas turbocharger is shifted as a function of the signaled operating mode of the transmission, wherein the first and / or second parameter characteristic curve is a function of an operating mode of the transmission, in particular, for example, of a gear stage or an upshift lock or the like operating mode.The development is based on the consideration that the shifting process of the turbo-supercharger group, in particular during idling operation and / or during load operation (i.e. under air compression) of the shift supercharger, has hitherto taken place without sufficient consideration of, for example, a selected gear stage or a transmission ratio limitation. The development has recognized, in particular, on the one hand that different power requirements for the engine occur in the lower gear stages than in higher gear stages. The development has, on the other hand, recognized that this can lead to a conflict of goals with respect to the matching of the supercharger switching.The concept of the development proposes in an improving manner that the operation of the basic exhaust gas turbocharger and / or switching exhaust gas turbocharger of the exhaust gas turbo-supercharging group takes place, in particular is activated and / or deactivated, as a function of the values of at least one parameter group of at least two operating parameters. The two operating parameters preferably comprise at least one rotational speed (nATL1) of the basic exhaust gas turbocharger and one rotational speed (nMOT) of the engine.In a particularly preferred development, it is proposed that the operation of the shift exhaust gas turbocharger in idling is activated as a function of the values of a first parameter group of operating parameters, which consists of the operating parameters: a rotational speed (nATL1) of the basic exhaust gas turbocharger, a rotational speed (nMOT) of the engine and a load-determining operating parameter of the engine. In other words, in a first partial variant, the development proposes to switch the idling operation of the shifting exhaust gas turbocharger as a function of both the rotational speed of the basic exhaust gas turbocharger and the rotational speed of the engine and also as a function of a load-determining operating parameter of the engine. According to the first partial variant, it is thus ensured that the idling operation of the shift exhaust gas turbocharger already takes place only at a point in time at which the rotational speed of the basic exhaust gas turbocharger and / or the rotational speed of the engine is sufficiently high and, in addition, the engine has a sufficient load reserve in order to be able to activate the idling operation of the shift exhaust gas turbocharger in an improved manner. An appreciable power dip and / or torque weakness of the exhaust gas turbo-supercharging group is reduced or completely avoided in the shifting process. In a particularly preferred development, the load-determining operating parameter of the engine is an injection quantity. It has advantageously been recognized that the injection quantity allows a particularly realistic determination of the load of the engine, since all control efforts fundamentally amount to the control of the injection quantity-in addition to the injection time and the rail pressure-in. In principle, a setpoint or actual value of the injection quantity can be used as load-determining operating parameter.Additionally or alternatively, according to a second partial variant of the refinement, it is provided that the operation of the shift exhaust gas turbocharger under air compression is activated as a function of the values of a second parameter group of operating parameters, which consists of the operating parameters: a rotational speed (nATL2) of the shift exhaust gas turbocharger, a rotational speed (nATL1) of the basic exhaust gas turbocharger and a rotational speed (nMOT) of the engine. In other words, the second partial variant of the concept according to the invention for activating an air-compressing load operation of the shift exhaust gas turbocharger takes into account both the rotational speed of the shift exhaust gas turbocharger itself and the rotational speed of the basic exhaust gas turbocharger and the rotational speed of the engine. This ensures that when the load operation of the shift exhaust gas turbocharger is activated, not only has the rotational speed of the shift exhaust gas turbocharger increased to a sufficiently high rotational speed during idling, but it is also taken into account that the rotational speed of the basic exhaust gas turbocharger supporting the shift operation and the rotational speed of the engine are also sufficiently high. By means of the shift operation as a function of all operating parameters of the second parameter group, the load operation of the shift exhaust gas turbocharger is made possible without appreciable power dip and / or torque weakness.Within the scope of a particularly preferred development of the second subvariant, it has proven to be advantageous that the second parameter group of operating parameters consists of the operating parameters: ratio (Q) of a rotational speed (nATL2) of the shift exhaust gas turbocharger to a rotational speed (nATL1) of the basic exhaust gas turbocharger, a rotational speed (nATL1) of the exhaust gas turbocharger and a rotational speed (nMOT) of the engine. Since in this development the ratio of the rotational speeds of the shifting exhaust gas turbocharger and of the basic exhaust gas turbocharger as operating parameters enters directly into the second parameter group influencing the shifting of the shifting exhaust gas turbocharger, it is directly taken into account that the air-compressing activation of the shifting exhaust gas turbocharger takes place only at a sufficiently high ratio of the rotational speed of the shifting exhaust gas turbocharger to the rotational speed of the basic exhaust gas turbocharger. The dependence of the rotational speeds on one another is thus directly implemented by the ratio of the same as operating parameters for the regulation. Advantageously, for the control method itself, the ratio is queried cyclically and stored in a memory, for example in percentages. The ratio can be multiplied by values of the rotational speed of the basic exhaust gas turbocharger which are likewise queried, and the result of the multiplication can be used to determine the triggering of the second activation signal. With this control rule, an air-compressing load operation of the shifting exhaust gas turbocharger can be engaged practically without appreciable torque weakness and / or power dip; nevertheless, the engagement process can be adjusted comparatively reliably and with nevertheless low computing effort and efficiently.The first and second subvariances of the development can be used alone independently of one another and preferably in combination with one another for achieving an improved control of a register charging, in particular an improved switching behavior of the switching exhaust gas turbocharger. As a result, even in heavy vehicles with highly charged engines and comparatively low displacement, a significantly improved control for register charging is achieved. The transient dynamic driving behavior is significantly improved even in heavy vehicles, in particular heavy commercial vehicles or military vehicles, since the supercharger switching state is adapted depending on the load state of the engine and additionally depending on a rotational speed of the engine and / or the rotational speed of the basic or switching exhaust gas turbocharger. Overall, a distinct reduction of a charge pressure dip during the shifting of the shifting exhaust gas turbocharger is established within the scope of the realization of the refinement.It has proven to be preferred that the exhaust gas switching device is formed as an exhaust flap which can be actuated by the first activation signal and / or the charge air switching device is formed as a charge air flap which can be actuated by the second activation signal. In principle, valves or similar actuators can also be used as the switching device; however, flaps have proven to be comparatively easy to maintain and simple to regulate.Within the scope of a particularly preferred development, at least the base turbine and / or the switching turbine is a turbine with variable turbine geometry. A turbine with variable turbine geometry is designed-suitable in particular for low exhaust gas flows-to provide the flow with a denser cross section and higher flow resistance (closed geometry) and designed-suitable in particular for high exhaust gas flows-to provide the flow with a more open cross section and lower flow resistance (open geometry); this can be achieved, for example, by adjusting the turbine blades against the flow.Exemplary embodiments of the invention will now be described below with reference to the drawing in comparison with the prior art, which is in part likewise illustrated. This is not necessarily intended to represent the exemplary embodiments to scale; rather, the drawing is, where appropriate for the purpose of explanation, embodied in a schematic and / or slightly distorted form. With regard to additions to the teachings that can be directly recognized from the drawing, reference is made to the relevant prior art. It should be understood that various modifications and changes may be made to the form and detail of an embodiment without departing from the general spirit of the invention. The features of the invention disclosed in the description, in the drawing and in the claims can be essential for the development of the invention both individually and in any combination. Moreover, all combinations of at least two of the features disclosed in the description, the drawing and / or the claims fall within the scope of the invention. The general idea of the invention is not limited to the exact form or detail of the preferred embodiment shown and· described below, or limited to an article that would be limited compared to the article claimed in the claims. In the case of specified rated ranges, values lying within the stated limits are also to be disclosed as limit values and can be used and claimed as desired. Further advantages, features and details of the invention will become apparent from the following description of the preferred exemplary embodiments and from the drawing; this shows in:In detail, the drawing shows: FIG. 1 : shows a schematic illustration of an internal combustion engine having an engine and an exhaust gas turbo-supercharging group for illustrating a register supercharging, in which an electronic control device for controlling the internal combustion engine is provided, which electronic control device has a module for electronic supercharger control and a module for electronic transmission control, which is assigned to a transmission having in the present case six gear stages; FIG. 2 : various characteristic curves of an accelerator pedal position as a function of a rotational speed on the transmission side; FIG. 3 : a three-dimensional characteristic curve field for the representation of a vitality signal indicating the vitality reserve of the engine as a function of two operating parameters influencing the vitality reserve of the internal combustion engine, namely the engine speed (nMOT) and a supercharging pressure, in this case a charge air pressure (pLL),FIG. 1 schematically shows an internal combustion engine 1000 having an exhaust gas turbo-supercharging group 100, an engine 200, and having a charging system 300 designed for guiding exhaust gas AG and charge air LL, and a transmission 500. Furthermore, FIG. 1 schematically shows the availability of a signaling on a data bus 430 CAN. Connected to the data bus 430 is an engine control unit 400, as well as an electronic supercharger control module (ELS) 410 and an electronic transmission control module (EGS) 420. Data relating to the supercharger operating state and the transmission operating state are thus present on the data bus 430.Here, the engine 200 is formed with an engine block 210 and a V-arrangement of ten cylinders, namely, cylinders A 1 to A 5 on an A-side A and cylinders B 1 to B 5 on a B-side B of the engine block 210. Via the exhaust turbocharger group 100 and the charge management system 300, charge air LL may be supplied to the cylinders via charge air manifolds 220A, 220B connected to the engine block 210. Specifically, charge air LL is supplied in a charge air duct 310 to the charge air manifolds 220A, 220B via branch lines, not shown in detail. The charge air LL is compressed together with injected fuel of a specific injection quantity qV at each compression phase of the crankshaft in the cylinders and serves for the combustion of the fuel. The combustion products are discharged as exhaust gas AG via exhaust manifolds 230A, 230B back into the charge guidance system 300. The exhaust gas AG is taken in from the exhaust manifolds 230A, 230B into an exhaust duct 320 and discharged to the atmosphere via the exhaust turbo-supercharging group 100.The torque generated by the engine 200 is transmitted on its power side via the crankshaft to the transmission 500, which has six gear stages for conversion to the further drive train (transmission, final drive, drive shaft).For controlling the internal combustion engine, a vehicle controller (called an ECU or ADEC) 400 and a data bus 430 in the form of a bus system (CAN) are provided. Also connected to the vehicle controller 400 via the data bus 430 is an electronic transmission control module 420 and an electronic supercharger control module 410.Specifically, exhaust gas turbo-supercharging group 100 is formed as a register supercharging with a first exhaust gas turbocharger in the form of a basic exhaust gas turbocharger 110 and a second exhaust gas turbocharger in the form of a switched exhaust gas turbocharger 120. The basic exhaust gas turbocharger 110 has a basic compressor 111 for charge air LL and a basic turbine 112 with variable turbine geometry VTG 1 for exhaust gas AG. The switching exhaust gas turbocharger 120 has a switching compressor 121 and a switching turbine 122 with variable turbine geometry VTG 2 for exhaust gas AG. The switching exhaust gas turbocharger 120 can be connected via a switching device 130 in addition to the basic exhaust gas turbocharger 110 which is in principle permanently operated. The switching device 130 has a charge air switching device 131 provided with a first regulator R 1 in a switching partial line 312 of the charge air guide 310, which branches off from a basic charge air guide 311. In addition, an exhaust gas switching device 132 assigned to the switching turbine 122 is provided with a second regulator R 2 in an exhaust gas switching sub-line 322 which branches off from an exhaust gas base line 321.The first and second controllers R 1, R 2 and adjusting elements for the variable turbine geometry VTG 1, VTG 2 are connected via corresponding control lines to the vehicle controller 400 via an electronic supercharger control module 410 of the electronic supercharger controller ELS. For this purpose, corresponding control lines 411, 412 of the data bus 430 (e.g. CAN bus or ADEC) are provided between the supercharger control module 410 and the controllers R 1, R 2 or the location elements for the variable turbine geometry VTG 1, VTG 2.In the present case, charge air LL is supplied via a basic charge air duct 311, to a basic compressor 111, which is driven via a basic turbine 112 driven by exhaust gas AG in the basic exhaust gas duct 321. The compressed charge air LL is cooled in a heat exchanger 330 and is further supplied in the charge air duct 310-as explained above-to the charge air manifolds 220A, 220B and to the cylinders A1 to A5 or B1 to B5. The basic exhaust gas turbocharger 110 is operated as a function of load at changing rotational speeds nATL 1.In the activation operation of the exhaust gas turbo-supercharging group 100, the switching exhaust gas turbocharger 120 is initially operated in idling operation with guidance of exhaust gas AG via the switching turbine 122 without guidance of charge air LL via the switching compressor 121, as soon as it is detected that a limit value of a first parameter characteristic curve has been reached; i.e. in the acceleration process with increasing rotational speed nATL2when the mass inertia is overcome and without additional load, since initially no charge air LL is compressed via the switching compressor 121. For this purpose, the exhaust gas switching device 132 assigned to the switching turbine 122 opens. The switching exhaust gas turbocharger 120 can thus initially be accelerated comparatively quickly without compressor work and exhaust gas AG can nevertheless be effectively blown off-if required. As the exhaust gas quantity continues to increase, the charge air switching device 131 assigned to the switching compressor 121 is also opened and the operation of the switching exhaust gas turbocharger 120 is activated under air compression, i.e. as load operation, as soon as it is detected that a limit value of a second parameter characteristic curve has been reached.The activation of the switching exhaust gas turbocharger 120--i.e. in the present case the opening of a charge air flap to form the charge air switching device 131 and then of an exhaust gas flap to form the exhaust gas switching device 132--takes place cleanly shielded and only with comparatively low charge pressure loss.FIG. 2 shows, by way of example and symbolically, different characteristic curves of an accelerator pedal position FP as a function of a rotational speed on the transmission side, which characteristic curves illustrate an upshift process HS, a downshift process RS and a delayed downshift process RS0. A first characteristic curve FP-HS representing an upshift provides that with increasing accelerator pedal position, the speed on the transmission side increases above a kickdown point in the range KD-HS with a greater gradient and then increases further for the further increase of the accelerator pedal position. Running through qualitatively similar but in the opposite direction is a characteristic curve FP-RS, which describes the accelerator pedal position during a shift-down process. On the one hand, the shift-back process takes place at lower speeds on the transmission side and, on the other hand, the shift-back kickdown range KD-RS is arranged at higher accelerator pedal positions than in the shift-up process.According to the present concept, it has been recognized that the upshift characteristic curve FP-HS and the downshift characteristic curve FP-RS are situated comparatively close to one another, so that, in particular during a driving operation at high load-such as, for example, in a terrain region with variable high load demand-pendulum shift processes, it is possible for a transmission-downstream rotational speed to fluctuate in the kickdown regions KD-HS and KD-RS; however, in any case, a tendency toward pendulum shift processes in these and other situations cannot be ruled out reliably in the case of characteristic curves situated comparatively close to one another. Disadvantageously, an automatic transmission could continuously shift back and forth between a lower gear stage and a higher gear stage, i.e., perform pedal shifting operations. This not only leads to an unfavorable driving behavior, but represents a serious restriction during driving under high load, which may possibly lead to the load requirement not being able to be ensured as a result.The concept of the invention realized with reference to FIG. 3 within the scope of a preferred embodiment makes it possible, by means of a vitality signal indicating the vitality reserve of the internal combustion engine 1000, for the downshift characteristic curve KD-RS to be lowered at lower speeds on the transmission side to a deceleration characteristic curve KD-RSO, which is illustrated by dashed lines in FIG. 2.As a result, the rotational speed interval between an upshift process HS and a downshift process RS 0 increases by a sufficient amount, so that pendulum shifts, in particular in a critical kickdown range KD, are virtually ruled out. In the present case, a downshift limit value of a rotational speed parameter, namely a rotational speed of a transmission output nAB for a specific gear stage, is retained as a function of the vitality signal--i.e. is executed according to the downshift characteristic curve KD-RS--or is lowered to a deceleration limit value--i.e. is executed according to the lowered characteristic curve KD-RSO. The downshift limit value on the lowered characteristic curve KD-RSO is below the downshift limit value of the normal downshift characteristic curve KD-RS with respect to the transmission-downstream rotational speed nAB. As can be seen from FIG. 3, a vitality signal is ascertained as a function of two operating parameters that influence the vitality reserve of the internal combustion engine, namely in the present case an engine speed nMOTand a charge air pressure pLL.It is ensured that the shift-back behavior from a higher gear stage to a low gear stage is delayed only for a group of higher gear stages--namely in the present case a group of gear stages which comprises the sixth, fifth and fourth gear stages. Likewise, a downshift can only take place into a group of lower gear stages--namely in the present case the gear stages of fifth, fourth, third and second gear. This ensures that the driving behavior which is dependent on the normal and greatly low load is carried out at the lower gear stages one, two and the reverse gear stages according to the normal characteristic curve, i.e. normal shift-down characteristic curve KD-RS and the shift-up characteristic curve KD-HS.It is also apparent from FIG. 3 that a downshift delay is permitted only for an engine speed range between 2,000 U / min and 3,100 U / min; i.e., a speed range with a sufficient torque increase. Likewise, a downshift delay is provided only in a range of a supercharging pressure between 2 bar and 3.1 bar. The lower limit values are symbolically drawn in FIG. 3 for this purpose. A limit value characteristic curve GWKL is also drawn in, which separates a half-plane of sufficiently good vitality values from a half-plane of inadequate vitality values taking into account engine speed nMOT and charge air values pLL. In the latter case, a digital vitality signal is set to 0. In the former case, i.e. above the limit value line GWKL, the vitality signal can be set to 1.In addition, it is taken into account in the present case that an engine speed should in any case be above nMOTmin=2,000 U / min and a charge air value should be above pLLmin=2 bar. As a result, a vitality signal for indicating a sufficient vitality margin of the motor is set to a logic "1" only in the region shown by hatching in FIG. 3. If, in such a case, the gear stage is additionally signaled six, five, four or three, a downshift delay can be implemented by means of the lowered characteristic curve KD-RSO of FIG. 2.A three-dimensional characteristic curve field illustrated in FIG. 3 can be executed, for example, between engine speeds of 2,000 revolutions per minute and 3,100 revolutions per minute with support points in 100th steps and can be executed in a charge air pressure range between 2 bar and 3.1 bar with support points in 0.1 bar steps. A vitality signal represented on the Z axis is executed with a digital value 0 or 1 for all interpolation nodes. Overall, a 12 x 12 x 2 matrix is thus obtained as a three-dimensional characteristic field for the representation of a vitality signal as a function of the engine speed and the charge air pressure.In the event of a sensor failure, such as a failure of a charge pressure sensor or of a rotational speed sensor, or some other defect in the control, the normal characteristic curves KD-RS and KD-HS must be assumed.In detail, the vitality signal is transmitted to a CAN data bus and, with a further improvement, comprises a 2-bit value, namely as follows: 0 0 switch-back enabled (non-vital-vitality signal 0) 0 1 delay switch-back (vital-vitality signal 1) 1 0 not used 1 1 not availableIn addition, a 1-bit signal may be provided, which indicates whether vital data are present for an internal combustion engine 1000 or whether vital data are not present (present 0, not present 1).In a particularly simple embodiment, for example, the following can be seen: Motor vital data (nMOT) provided on the CAN data bus on the motor side are present;vital data (pLL) provided on the CAN data bus by the turbo charger are present;a transmission-side evaluation according to FIG. 3 provides that a vitality signal is signaled to 1;a shift-back delay is provided in such a way that only at an engine speed nMOT of 2,555 U / min is a shift from a higher gear stage to a low gear stage with regard to gears six, five and four.Reference numerals denote reference numerals100 Exhaust gas turbo-supercharging group 110 Basic exhaust gas turbocharger 111 Basic compressor 112 Basic turbine 120 Switching exhaust gas turbocharger 121 Switching compressor 122 Switching turbine 130 Switching device 131 Charge air switching device 132 Exhaust gas switching device 200 Engine 210 Engine block 220A, 220B Charge air manifold 300 Charge guidance system 310 Charge air guide 311 Basic charge air guide 312 Exhaust gas switching device 310 Charge air guide 321 Basic exhaust gas guide 322 Exhaust gas switching sub-line 330 Heat exchanger 400 Vehicle controller 410 Supercharger control module 411 Control line 412 Control line 420 Transmission control module 430 Data bus 500 Transmission 1000 Internal combustion engine A 1, B 1 First cylinder A 2, B 2 Second cylinder A 3, B 3 Third cylinder A 4, B4 fourth cylinder AG exhaust gas FP accelerator pedal position FP-HS representative characteristic curve FP-RS characteristic curve HS upshift process KD-HS kickdown point KD-RS downshift kickdown range LL charge air nATL1, nTAL2 rotational speeds nMOT engine rotational speed pLL charge air pressure qV injection quantity RS regulator RS0 delayed downshift process RS1 first regulator RS2 second regulator VTG1, VTG2 turbine geometry KD-RSO deceleration characteristic curve GWKL limit value characteristic curve

Claims

Method for controlling a drive comprising a transmission (500) and an internal combustion engine (1000) having an engine (200), an exhaust gas turbo-supercharging group (100) which has a basic exhaust gas turbocharger (110) and a shift exhaust gas turbocharger (120) for the engine (200), wherein - the shift exhaust gas turbocharger (120) is designed to be operated in addition to the basic exhaust gas turbocharger (110) and having the transmission (500) with a number of gear stages, for controlled shifting of the transmission (500) and / or for controlled operation of the engine (200) and / or for controlled shifting of the register charging of the internal combustion engine (1000), wherein - one of the number of gear stages of the transmission (500) is shifted as a function of a limit value of a rotational speed parameter, an indicating vitality signal of a vitality reserve of the internal combustion engine (1000) is signaled, wherein the vitality signal is determined as a function of at least two operating parameters influencing the vitality reserve of the internal combustion engine (1000), namely a first operating parameter of the engine (200) and a second operating parameter of the exhaust gas turbo-charger group (100), wherein the two operating parameters influencing the vitality reserve of the internal combustion engine (1000) are an engine rotational speed (nMOT) and a charge air pressure (pLL), and - a downshift limit value of the rotational speed parameter for the one of the number of gear stages is retained as a function of the signaled vitality signal or is lowered to a deceleration limit value which is below the downshift limit value, The downshift limit value is reduced to the deceleration limit value for a third or higher gear stage and is limited to the third or higher gear stage, wherein - the one of the number of gear stages of the transmission (500) is signaled, and - the downshift limit value and the deceleration limit value are dependent on and specific to the one of the number of gear stages of the transmission.Method according to Claim 1, characterized in that it is indicated by means of the vitality signal whether or not the vitality reserve of the engine is present, wherein the vitality reserve of the engine (200) is present if the engine rotational speed (nMOT) is above a vitality limit value of the engine rotational speed (nMOT) and the charge air pressure (pLL) is above a vitality limit value of the charge air pressure (pLL).Method according to Claim 1 or 2, characterized in that the operating parameter which influences the vitality reserve of the internal combustion engine (1000) is signaled from the engine (200) on the engine side and / or the operating parameter (1000) which influences the vitality reserve of the internal combustion engine is signaled from the exhaust gas turbo-supercharging group (100) to a data bus and is evaluated on the transmission side with generation of the vitality signal.Method according to one of the preceding claims, characterized in that the vitality signal and the two operating parameters which influence the vitality reserve of the internal combustion engine (1000) are defined within the scope of an at least three-dimensional characteristic field.Method according to one of the preceding claims, characterized in that the downshift limit value is in a range of an engine speed (nMOT) above 2000 U / min to 3100 U / min.Method according to one of the preceding claims, characterized in that a shift-back delay is permitted in a range of a supercharging pressure between 2.0 bar and 3.1 bar.Method according to one of the preceding claims, characterized in that the shift-back delay is implemented by means of a parameter characteristic curve which is a function of an accelerator pedal position (FP) as a function of a transmission rotational speed on the transmission side and the engine rotational speed, and - the shift-back delay is still permitted above a lowered parameter characteristic curve (KDO) which characterizes a lowered shift-back threshold, wherein - instead of above a parameter characteristic curve (KD) which characterizes a normal shift-back threshold, the lowered parameter characteristic curve (KDO) runs at lower rotational speeds than the normal parameter characteristic curve (KD).Method according to Claim 7, characterized in that - the lowered parameter characteristic curve (KDO) runs in an upper rotational speed range above a first minimum accelerator pedal position (90%), and - the normal parameter characteristic curve (KD) runs above a second minimum accelerator pedal position (80%), - the first minimum accelerator pedal position (90%) being greater than the second minimum accelerator pedal position (80%).Method according to one of the preceding claims, characterized in that a shift from a higher gear stage to a lower gear stage is not delayed if a defect is detected.Method according to one of the preceding claims, characterized in that - the basic exhaust-gas turbocharger (110) has a basic compressor (111) for charge air (LL) and a basic turbine (112) for exhaust gas (AG), wherein the basic turbine (112) is designed to drive the basic compressor (111), - the switching exhaust-gas turbocharger (120) has a switching compressor (121) for charge air (LL) and a switching turbine (122) for exhaust gas (AG), wherein the switching turbine (122) is designed to drive the switching compressor (121), and wherein - the switching exhaust-gas turbocharger (120) is designed to be operated in addition to the basic exhaust-gas turbocharger (110), wherein: the operation of the basic exhaust gas turbocharger (110) and / or the switching exhaust gas turbocharger (120) is switched, namely activated and / or deactivated, as a function of the values of at least one parameter group of at least two operating parameters.Method according to one of the preceding claims, further comprising the steps: - operating the basic exhaust gas turbocharger (110) at changing rotational speeds (nATL1); - detecting a limit value of a first parameter characteristic curve, namely a limit value rotational speed (GW-nATL1) of the basic exhaust gas turbocharger and / or a limit value rotational speed (GW-nMOT) of the engine (200); - operating the shift exhaust gas turbocharger (120) at idle, with guidance of exhaust gas (AG) via the shift turbine (122), without guidance of charge air (LL) via the shift compressor (122); identifying a limit value of a second parameter characteristic curve, and operating the switching exhaust gas turbocharger ( 120) under air compression (LL) with guidance of exhaust gas (AG) via the switching turbine ( 122) and guidance of charge air (LL) via the switching compressor ( 122).Method according to one of the preceding claims, characterized in that operation of the switching exhaust-gas turbocharger (120) is signaled in addition to the basic exhaust-gas turbocharger (110).Method according to one of the preceding claims, characterized in that the operation of the shift exhaust-gas turbocharger (120) at idle is activated as a function of the values of a first parameter group of operating parameters which consists of the operating parameters: a rotational speed (nATL1) of the basic exhaust-gas turbocharger, a rotational speed (nMOT) of the engine and a load-determining operating parameter of the engine, namely a SETPOINT or ACTUAL value of the injection quantity (qV).Method according to one of the preceding claims, characterized in that the operation of the shift exhaust-gas turbocharger (120) under air compression is activated as a function of the values of a second parameter group of operating parameters which consists of the operating parameters: a rotational speed (nATL2) of the shift exhaust-gas turbocharger, a rotational speed (nATL1) of the basic exhaust-gas turbocharger, namely a ratio thereof, and a rotational speed (nMOT) of the engine (200).Control device for an internal combustion engine (1000) having a control unit, wherein the control unit is designed to control the exhaust gas turbo-supercharging group (100) according to one of the methods according to one of Claims 1 to 14.Internal combustion engine (1000) having an engine (200) and having an exhaust gas turbo-supercharging group (100) which has a basic exhaust gas turbocharger (110) and a shift exhaust gas turbocharger (120) for the engine (200), and having a control device for controlling a drive comprising the internal combustion engine (1000) and a transmission (500), wherein the control device is designed to control the drive according to one of the methods according to one of Claims 1 to 14.

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