DE102018122543A1 - Method for starting an internal combustion engine in a hybrid vehicle by means of selective cylinder deactivation - Google Patents

Abstract

The method presented for starting an internal combustion engine in a hybrid vehicle reduces the vibration excitation of the vehicle drive train when changing from electric driving mode to hybrid driving mode and thus prevents noise emissions and vibrations which the driver perceives as unpleasant. In contrast to known methods, such as the macro slip control of a drive clutch or the control of the electric machine, the targeted suspension of the firing of individual cylinders in the clutch process neither requires additional energy nor generates power loss in the form of frictional heat. Furthermore, unlike the conventional methods, the cause of the vibration excitation is counteracted instead of damping the resulting vibration. No additional peripherals are required for the method presented, and space can even be saved, since the separating clutch can be designed to be less robust than with pure macro slip control. In addition, the method presented can be freely combined with the already known methods, as a result of which the possibilities for damping vibrations when starting an internal combustion engine in a hybrid vehicle are multiplied.

Description

Technical field

The present invention relates to a method for starting the internal combustion engine of a hybrid vehicle, which is characterized in particular by the use of a selective cylinder deactivation of the internal combustion engine for vibration damping, according to claim 1.

State of the art

Various embodiments of the drive train of hybrid vehicles are sufficiently known from the prior art. In the case of parallel or power-split hybrid vehicles in particular, there is an advantage in that an internal combustion engine and at least one electrical machine drive the wheels of a vehicle axle either together or separately from one another. In other words, such a hybrid vehicle can be operated in purely electrical operation (EV, “electric vehicle”) or in the combination of internal combustion engine and electrical machine as a hybrid drive (HEV, “hybrid electrical vehicle”). A corresponding arrangement, consisting of at least one internal combustion engine, hereinafter referred to as an internal combustion engine (VKM), at least one electrical machine (EM) and various clutches and gearboxes is required for the use of the functions described.

Different stages of hybridization of the vehicle result from different arrangements of one or more EM within the vehicle drive train. In the most rudimentary electrification of a vehicle drive train, the VKM has a belt starter generator. In this stage of hybridization, also known as P0 hybrid, where the EM is integrated in the belt drive of the VKM and can be used as a starter or generator, hybrid functions such as boost, recuperation or internal combustion engine sailing are possible. In the case of a P1 hybrid, the EM is arranged in a manner fixed to the crankshaft between the ICE and the drive clutch. Like the P0 hybrid, the EM can be operated as a starter, booster and generator. The same hybrid functionalities can be represented with the P1 hybrid as with the P0 hybrid, however, pure EV operation is not yet possible in both stages. EV operation is only at the hybridization level P2 or higher realizable. In 1 an embodiment of a P2 hybrid is shown as an example. The VKM ( 2nd ) and an associated dual mass flywheel ( 3rd ) are via a disconnect clutch ( 4th ) with an EM ( 5 ) arranged to be selectively coupled. The EM ( 5 ) can be selectively coupled in the further power flow via a drive clutch ( 6 ) with the gearbox input shaft of a gearbox ( 7 ) connected. The arrangement of the EM ( 5 ) between the disconnect clutch ( 4th ) to the VKM ( 2nd ) and drive clutch ( 6 ) or gear ( 7 ) enables EV operation of the hybrid vehicle as well as other hybrid functionalities such as electrical creep, electrical sailing and recuperation with uncoupled VKM ( 2nd ). The power flow leads from the gearbox ( 7 ) further on a differential gear ( 10th ) and via the drive shafts ( 9 ) on the vehicle wheels ( 8th ). The same hybrid functionalities as with the P2 hybrid can also be mapped with P3 hybrids and higher levels of hybridization, with the drive clutch ( 6 ) at a position before the EM ( 5 ) is arranged so that the EM ( 5 ) not from the driving wheels ( 8th ) is separable. As P3 -Hybrids are therefore referred to drive trains in which the EM ( 5 ) between gearbox ( 7 ) and differential gear ( 10th ) is arranged. The hybrid structure can perform essentially the same hybrid functionalities as a P2 hybrid, but starting the VKM ( 2nd ) by the EM ( 5 ) not possible when the vehicle is stationary. At P4 - and P5 hybrids is the EM ( 5 ) completely from the VKM ( 2nd ) decoupled. It is either arranged on a further driving vehicle axle (P4 hybrid) or directly as a wheel hub motor (P5 hybrid). By P4 - In addition to the hybrid functionalities already mentioned, an electric all-wheel drive can also be implemented.

The development of modern hybrid vehicles results in the primary requirements for packaging, such as installation space and complexity, performance, such as acceleration behavior and power output, as well as comfort, such as vibration behavior and fuel efficiency. Switching between the operating modes EV and HEV is particularly important for these properties. A changeover process from EV to HEV is essentially dependent on either the state of charge of a battery (SOC) or a torque request, for example by the accelerator pedal due to the driver's request for acceleration. If the SOC of a battery falls below a limit value, the operation of the HEV is activated in order to charge the battery in generator mode. However, since, depending on the load, the torque requirement on the ICE is not always so high that it can be operated at its nominal point in order to achieve optimal fuel efficiency, the ICE runs in the driving cycle proportionately often in the range of low engine speeds, which leads to increased fuel consumption. Regardless of a battery and its SOC, there is a switchover to HEV operation by means of an acceleration request, so that the ICE supports the EM in the torque generation with its output torque. If the above requirements for an increased energy requirement are overcome, a switchover from HEV operation back to EV operation can take place. In terms of performance and comfort, the number of Switching operations between modes of operation may be minimal. This requirement is particularly illustrated by the loss of comfort that arises when the VKM is started. The VKM must either be started electrically or towed on the one hand and then connected to the rest of the drive train, either via a claw or a friction clutch. Although this process only corresponds to a time period of less than one second, it is associated with an unexpected noise and vibrations in the vehicle for the driver. The number and timing of the VKM's start processes can only be influenced indirectly by the driver and are therefore perceived as disturbing.

In order to meet these requirements, there are different approaches in the prior art. A variant for saving fuel and reducing the switching processes consists of the torque adjustment of the ICE in the low-load range. In the published application JP2011236871A the control for a VKM within a hybrid vehicle application is presented, with the VKM having several cylinder banks. If the torque requirement is low, a cylinder bank can be switched off and only half of the cylinders are fired in the VKM. A cylinder bank deactivation, however, requires a VKM with separate cylinder banks, whereas in the development of hybrid series passenger cars mostly 3- or 4-cylinder in-line units are used.

In the patent US8892330B2 discloses a hybrid vehicle with cylinder deactivation, with no defined number of cylinders or no defined structure of the VKM being prescribed. The cylinder is deactivated according to predetermined ignition patterns, depending on the operating state of the ICE. A variable displacement is thus set, so that an unlimited number of cylinders remains unfired per work cycle of the ICE. Variable adjustment of the displacement, depending on the internal combustion engine operating state, enables the need-based reduction of the fuel consumption of the ICE in a hybrid vehicle.

In the patent DE112013007204T5 A control device for an internal combustion engine in a hybrid vehicle application is presented, the switchover between EV and HEV operation of the hybrid vehicle being optimized by means of selective cylinder deactivation. In the control device, a switchover between a complete cylinder operation and a cylinder deactivation operation depending on the operating point of the ICE is provided, as well as the switchover between EV and HEV operation. However, as already explained, frequent switching between the different operating modes leads to driver discomfort with regard to noise emissions and vibration behavior of the vehicle drive train. To avoid frequent switching of the operating modes, some control strategies are presented. If, for example, the VKM was started in a defined period to switch from EV to HEV operation, the energy requirement requirement was overcome after a short time and the battery also has a high SOC, the hybrid vehicle still remains in HEV operation and does not switch back to EV operation. Instead, a certain cylinder deactivation operation is preferred, so that the VKM does not have to be started frequently and the fuel consumption remains moderate. If there is an energy demand requirement due to low SOC of the battery without increased torque requirement, the ICE can switch to cylinder deactivation mode even when stopped and start with the cylinders switched off. Due to the diverse operating strategies, frequent switching between EV and HEV operation can be avoided, which leads to reduced noise emissions and increased driving comfort due to vibration reduction, whereby the hybrid operation of the vehicle is fully guaranteed and fuel consumption is kept moderate.

Depending on the driving profile and driving conditions, switching between EV and HEV operation is still necessary. During the start of the VKM, it can be started using a separate starter or started using an EM connected to the crankshaft ( P0 - and P1 -Hybrid). At P2 -Hybrids or a higher hybridization level, the VKM can also be towed via a disconnect clutch. The speed of the VKM is continuously increased by a slip torque through the clutch. In the compression cycle of the VKM, air is compressed to increase the temperature. When a required speed is reached, a first cylinder ignites and the ICE starts. The VKM is then fully engaged and transmits its torque to the drive train. Towing by means of a disconnect clutch creates two requirements. On the one hand, the cranking process results in high reaction forces in the crankshaft as a result of the compression cycles of the VKM, which requires a correspondingly high torque capacity of the clutch, on the other hand, when the speed of the VKM and EM or the drive train is reached, vibration excitation or overshoot occurs , because the torque balance of the VKM changes the sign to a certain extent. In other words, the ICE takes up torque from the EM or the drive train until the ignition and the speed equality, and from the time of the engaged state, the ICE suddenly returns torque to the drive train. By the sudden reversal of the direction of the flow of force there is a jump in torque and unwanted vibrations.

In order to continue to maintain driving comfort and driving dynamics in the hybrid vehicle, there are already processes in the prior art which optimize the starting process of the ICE during EV operation with regard to vibration behavior. One possibility is to use a macro slip control. In the patent US9267481 B2 A start control for an internal combustion engine in a hybrid vehicle is presented, the amount of crank torque required to start the ICE to be reduced. The background to this is that if the acceleration requirement is high or dynamic, the required torque should be made available to the vehicle particularly quickly. The faster the ICE is supposed to start, the higher the reaction forces on the crankshaft, which means that an ever higher starting torque is required. In order to limit or reduce the required towing torque, a macro slip control is proposed, the clutch slip being increased in the lower speed range of the VKM and the VKM being reduced as the speed increases. In this way, the drivetrain suffers only minimal loss of motive power due to the EM, which at the same time drags the VKM.

It is also possible to dampen the self-excitation of the hybrid vehicle when the VKM is started by specifically regulating the EM. In the patent CN103386878B A method for starting the internal combustion engine of a hybrid vehicle is presented, the torque delivered for towing the VKM being adapted by the EM depending on the driving state, which in this method is essentially determined by the transmission input torque and the torque request. There is also the possibility of combining the macro slip control with an EM control in order to optimize a compromise between friction loss due to a disconnect clutch and additional energy requirements due to the EM.

The disclosed methods for improving the driving comfort and the dynamic behavior of hybrid vehicles with regard to the starting process of the ICE have some disadvantages. VKM torque and fuel consumption are actively influenced by cylinder deactivation while driving in order to reduce the number of VKM starts. However, the frequency of switching between EV and HEV operation in hybrid vehicles can only be influenced indirectly and a reduced vibration excitation has so far not been pursued by this technology. Through the use of a macro slip control, which is used in particular with a hybridization level of P3 or higher, the necessity of a constantly higher energy required by the VKM with regard to dynamic requirements is largely substituted by the friction of a clutch, but this also increases the power loss and the heat input the drive train and furthermore the separating clutch must be made more robust. EM control creates the advantage that vibration excitation in the drive train can be actively damped, but also increases the energy requirement, since in addition to driving the vehicle, additional torque must be provided to counteract the vibrations of the crankshaft of the ICE.

In order to use the advantages of the methods established in the prior art with regard to the vibration reduction when starting an ICE in a hybrid vehicle without being influenced by the disadvantages mentioned, the following invention is proposed.

Object of the invention

The object of the invention is to provide a method for starting an internal combustion engine in a hybrid vehicle, wherein a vibration excitation resulting from the starting process of the internal combustion engine is reduced by means of selective cylinder deactivation.

Solution of the task

The object is achieved by a method for starting an internal combustion engine in a hybrid vehicle according to the features of claim 1, further explanations result from the subclaims.

Presentation of the advantages and description of the invention

The invention provides a method for starting a VKM of a hybrid vehicle, the hybrid vehicle having at least one EM, at least one VKM, at least one clutch, and at least one device for detecting the state of motion of the crankshaft and a further device for detecting the state of motion of an element of the Has vehicle drive train. The VKM has at least one cylinder head with at least two cylinders. The VKM can also drive the EM for generator operation, which means that a vehicle battery can be charged. The disconnect clutch is located within the vehicle drive train between the VKM and the EM. The separating clutch is preferably designed as a friction clutch. The Devices for detecting the state of motion determine this for the crankshaft of the VKM and for an element of the vehicle drive train. The state of motion of the crankshaft and the element of the vehicle drive train can be a rotational speed or an oscillation state. In an advantageous embodiment of the method, the devices for detecting the state of motion are sensors, for example speed sensors. In an alternative embodiment, the movement states can be derived from other measured variables and partially or completely modeled. The element of the vehicle drive train is located directly on one side of the disconnect clutch, the other side of the disconnect clutch being connected to the ICE. Depending on the position of the EM, the element of the vehicle drive train can be, inter alia, the rotor shaft of the EM or an input shaft of a travel gear or an input shaft of a differential gear. In the case of a P2 hybrid drive structure, the EM is positioned immediately after the disconnect clutch and the element of the vehicle drive train is the transmission input shaft of the EM. In the case of a P3 hybrid structure, the EM can be located between the drive gear and the differential gear, the element of the vehicle drive train which is connected to the disconnect clutch being the drive gear input shaft. At higher hybrid levels, the clutch can also be connected directly to the differential gear.

The vehicle can be driven purely electrically in a purely electrical operation, the disconnect clutch being open and the vehicle drive train being completely decoupled from the VKM. The hybrid vehicle is driven exclusively by the output torque of the EM. Furthermore, the vehicle can be driven in a hybrid mode, the disconnect clutch being closed and the vehicle drive train being coupled to VKM and EM. The hybrid vehicle is driven from the common torque balance between VKM and EM. Switching between electrical operation and hybrid operation is possible both while driving, as well as with P2 hybrids or a lower hybridization level when the hybrid vehicle is at a standstill and is based on a request. In particular, the switch from electrical to hybrid operation can include result from a low state of charge of the vehicle battery or a torque request. The VKM is started for this.

The method according to the invention describes the starting process of the VKM of a hybrid vehicle, with the slip in the separating clutch between the crankshaft of the VKM and the vehicle drive train first being reduced after the start request and thus the transmissible torque from the vehicle drive train to the crankshaft being increased. At the same time, the output torque of the EM is increased, causing the crankshaft of the VKM to be towed. The torque delivered to the vehicle drive train should remain unaffected in order to ensure loss-free propulsion of the hybrid vehicle, the EM compensating the clutch torque. By towing the VKM, its speed is increased until a start threshold speed is reached. This represents the minimum speed at which the ICE can be started. When this minimum speed is reached, the first fuel is injected into a cylinder. The firing order is defined by the current crank angle at this point in time. The VKM then starts, with ignition conditions being established in all cylinders for the transition to fired operation. This is done by an appropriate injection of fuel. The VKM is then operated in fired mode due to its own energy conversion, releasing torque and in a high-load range and continues to increase the speed of the crankshaft until the speed on both sides of the clutch is synchronized. During the closing process of the disconnect clutch or immediately after the point of speed equality between the ICE and the vehicle drive train, a selective cylinder deactivation is selected and activated. The selection and the time of activation are determined on the basis of the state of motion of the crankshaft and vehicle drive train detected by the speed sensors, the operating state of the hybrid vehicle and / or influencing variables of the driving cycle. The state of motion of the crankshaft and vehicle drive train is preferably characterized by the speed and / or the state of vibration. The operating state of the hybrid vehicle is among others the current firing order of the VKM, the starting position of the crankshaft of the stopped VKM, the current speed of the crankshaft of the VKM and / or the vehicle drive train.

For the selective cylinder deactivation, at least one cylinder remains fired per work cycle, so that vibration excitation by the clutch process is counteracted. When selective cylinder deactivation is activated, ignition conditions are created for the selected cylinder or cylinders such that the latter cannot be operated with a fire. This can be done by keeping a fuel injector closed, by keeping inlet and exhaust valves closed, or by actively igniting the corresponding cylinder. The selective cylinder deactivation is activated in a moment during the closing process of the separating clutch or immediately afterwards. This moment is preferably the point in time immediately before or after the clutch is fully closed or at Achieving the same speed between the crankshaft of the VKM and the vehicle drive train, because at this moment the vehicle drive train is excited to vibrate. The selective cylinder deactivation can begin immediately before the disconnect clutch is closed and can be continued during the speed adjustment between the crankshaft of the ICE and the vehicle drive train. The selective cylinder deactivation is ended after the closing process of the separating clutch or immediately thereafter, the torque output of the VKM being increased further in the course of time thereafter and being transmitted through the separating clutch until the VKM applies a torque to the vehicle drive train that is required for driving the hybrid vehicle transmits.

In an advantageous embodiment of the method according to the invention, the state of motion of the crankshaft of the VKM and the vehicle drive train is detected before the speed of rotation of the crankshaft and the vehicle drive train is the same, and a corresponding selective cylinder deactivation starts even before the separating clutch is fully closed, so that subsequent vibration excitation is already prevented becomes.

The selection of the cylinders that are not fired with selective cylinder deactivation is made according to their firing order and the movement states of the crankshaft and vehicle drive train. In one embodiment of the invention, the switch-off patterns can be determined simulatively or on a test bench and stored as predetermined switch-off patterns and selected and activated in accordance with the movement states that occur. If, for example, the speed of the VKM overshoots at the moment the separating clutch is closed, the next cylinder, which would make a torque contribution according to the firing order, is operated without fire. This can be done for other work cycles. It is also possible to provide a switch-off scheme rotating over the cylinders. The switch-off pattern is selected in such a way that a vibration caused by the coupling and starting of the internal combustion engine is damped as effectively as possible.

The selective cylinder deactivation represents a particularly simple and programmable measure to dampen the vibration during the transition from purely electrical to hybrid operation. No additional sensors are required. Furthermore, a simple switch-off, e.g. B. the fuel injection.

When using stored shutdown patterns, almost no additional computing power is required. Further vibration damping control algorithms, e.g. B. the electric machine can be omitted if necessary. The control intervention on the fuel injection and / or ignition is possible almost in real time. The electrical control of the ignition and fuel injection is possible with cylinder and cycle play selectivity and is subject to almost no runtimes, which means that a quicker intervention can take place.

In a further advantageous embodiment of the method according to the invention, the selective cylinder deactivation is used in conjunction with a macro slip control of the clutch and / or a control of the EM. The combination of the selective cylinder deactivation with the two known methods for vibration damping when starting the ICE in a hybrid vehicle increases the flexibility and the possibilities for improving the self-excitation of the vehicle drive train.

Embodiment

1 shows an example of the structure of a hybrid vehicle powertrain ( 1 ) to implement the method presented for starting an internal combustion engine in a hybrid vehicle. The powertrain shown ( 1 ) corresponds to the hybridization level of a P2 hybrid. A VKM ( 2nd ) is together with an associated dual mass flywheel ( 3rd ) via a disconnect clutch ( 4th ) with the input shaft of an EM ( 5 ) selectively connectable. The EM is in turn via a driving clutch ( 6 ) with the input shaft of a gearbox ( 7 ) connected. The gear ( 7 ) leads the power flow to a differential gear ( 10th ), which on the drive shaft ( 9 ) the driven vehicle axle is arranged. The vehicle wheels ( 8th ) of the driving vehicle axle are connected to the drive shaft ( 9 ) connected.

In 2nd is a possible course of a start process of the VKM ( 2nd ) of a hybrid vehicle. The physical variables speed ( N ) and torque ( T0 ) are in the upper, the cylinder internal pressure ( P ) in the middle and the acceleration ( A ) is illustrated in the diagram below the horizontal time axis. For the speed ( N ) is the crankshaft speed in full line ( N1 ) of the VKM ( 2nd ) and the dotted line the speed ( N2 ) the EM ( 5 ). The torque ( T1 ) the disconnect clutch ( 4th ) is shown in the upper diagram by a dashed line and the torque ( T2 ) the EM ( 5 ) illustrated by a fine dashed line. The VKM ( 2nd ) is designed as a 4-cylinder unit in the example, the corresponding internal cylinder pressures ( P1 , P2 , P3 , P4 ) in the middle diagram in full line for the first cylinder ( P1 ), in a dotted line for the second cylinder ( P2 ), in dash-dotted lines for the third cylinder ( P3 ) and in fine dashed lines for the fourth cylinder ( P4 ) are shown. In the lower diagram the vehicle acceleration ( A ), dashed for the basic measurement ( A1 ), without cylinder deactivation, and in full line for the variant of the method according to the invention ( A2 ), with cylinder deactivation during the start of the VKM ( 2nd ). The data shown are standardized and contain no numerical values.

In the exemplary embodiment of the method according to the invention for starting an internal combustion engine in a hybrid vehicle by means of cylinder deactivation, the VKM ( 2nd ) started from EV operation. The EM ( 5 ) is already used as the drive source in the torque output to the drive train ( 1 ) at one speed ( N2 ), which also during the start of the VKM ( 2nd ) is maintained. To tow the VKM ( 2nd ) the disconnect clutch ( 4th ) closed to the extent that a slip moment on the VKM ( 2nd ) is transmitted. At the same time, the torque ( T2 ) the EM ( 5 ) and the transferable torque ( T1 ) the disconnect clutch ( 4th ) continuously increased ( S1 ). This also increases the crankshaft speed ( N1 ) of the VKM ( 2nd ) on. Due to the crankshaft rotation, the VKM ( 2nd ) first in the cylinder 1 and then in the cylinder 3rd , according to the firing order, compresses air so that the temperature in the cylinders is increased as a result. When a defined crankshaft speed is reached ( N1 ) fuel is injected into the cylinder following the ignition sequence, here cylinder 4th , and the VKM ( 2nd ) is running ( S2 ). The VKM ( 2nd ) now accelerates the crankshaft speed ( N1 ) by itself ( S3 ) to the point of speed equality ( S4 ) between the crankshaft and the input shaft of the EM ( 5 ). The current speed status of the VKM ( 2nd ) and the EM ( 5 ) must be recorded by the speed sensors, so that a pattern for selective cylinder deactivation can be determined and executed. In terms of speed equality ( S4 ) the torques ( T1 , T2 )) the EM ( 5 ) and the disconnect clutch ( 4th ) reduced ( S5 ). Furthermore, the vibration of the drive train also arises at this point ( S6 ). Immediately at this moment, the fuel injection becomes for the cylinders following the firing order, in this case cylinders 3rd and cylinder 4th , exposed to counteract the vibration excitation. In general, the suspension of the injection quantity of the individual cylinders depends on the firing order, the starting position of the cylinders during the start process of the ICE ( 2nd ) and the driving conditions. The now damped vibration of the vehicle acceleration ( A2 ) builds up compared to the test without cylinder deactivation ( A1 ), faster again ( S8 ) and at the same time the clutch torque of the separating clutch ( 4th ) increased until the VKM ( 2nd ) transmits its full torque ( S9 ).

Reference list

1

Hybrid vehicle powertrain

2nd

Internal combustion engine

3rd

Dual mass flywheel

4th

Separating clutch

5

Electrical machine

6

Driving clutch

7

transmission

8th

Vehicle wheel

9

drive shaft

10th

Differential gear

S1

Increase torque electric machine and clutch

S2

Initial ignition of a first cylinder

S3

Increase in engine speed

S4

Equal speed crankshaft and electrical machine

S5

Torque reduction electric machine and clutch

S6

Vibration excitation

S7

selective cylinder deactivation

S8

Propagation of damped vibration

S9

Increase clutch torque

A

acceleration

A1

Basic acceleration

A2

vibration-damped acceleration

N

rotational speed

N1

Crankshaft speed

N2

Speed electric machine

P

Cylinder pressure

P1

Internal pressure cylinder 1

P2

Internal pressure cylinder 2nd

P3

Internal pressure cylinder 3rd

P4

Internal pressure cylinder 4th

T

time

T0

Torque

T1

Clutch torque

T2

Torque electric machine

QUOTES INCLUDE IN THE DESCRIPTION

This list of documents listed by the applicant has been generated automatically and is only included for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Patent literature cited

• JP 2011236871 A [0005]
• US 8892330 B2 [0006]
• DE 112013007204 T5 [0007]
• US 9267481 B2 [0009]
• CN 103386878 B [0010]

Claims (9)

Method for starting an internal combustion engine of a hybrid vehicle, the hybrid vehicle having at least one electrical machine, at least one internal combustion engine, at least one disconnect clutch which is arranged in the vehicle drive train at a position between the internal combustion engine and the electrical machine, and at least one device for detecting the state of motion of the crankshaft the internal combustion engine and a further device for detecting the state of motion of an element of the vehicle drive train, which is selectively connectable to the internal combustion engine via the disconnect clutch, the hybrid vehicle, when the disconnect clutch is open, can be driven in a purely electrical mode, and, at closed disconnect clutch, can be driven in a hybrid operation, a switchover between the purely electrical operation to the hybrid operation taking place on the basis of a request and the internal combustion engine tmachine is started on the request, whereby at the same time a transmissible torque of the separating clutch between the crankshaft of the internal combustion engine and the electrical machine and the output torque of the electrical machine are increased until the speed of the crankshaft of the internal combustion engine has exceeded a starting threshold value and fuel into a first Cylinder is injected, whereby the internal combustion engine further increases the speed of the crankshaft due to its own energy conversion, until the speed is synchronized on both sides of the clutch, whereby due to the state of motion of the crankshaft and vehicle drive train detected by the devices, the operating state of the hybrid vehicle and / or the influencing variables of the driving cycle, a pattern for a selective cylinder deactivation is selected, which activates at a moment during the closing operation of the clutch or immediately afterwards rt and where at least one cylinder of the internal combustion engine cannot be fired in one or more successive work cycles during the activated selective cylinder deactivation, the selective cylinder deactivation being ended again after the closing process of the separating clutch and the torque that can be transmitted through the separating clutch by the internal combustion engine is increased further until the internal combustion engine transmits a torque that is required for driving the hybrid vehicle to the vehicle drive train. Procedure according to Claim 1 , characterized in that in addition to the selective cylinder deactivation, a macro slip control of the disconnect clutch and / or a control of the electrical machine is used. Procedure according to Claim 1 or 2nd , characterized in that the requirement for switching from electrical operation to hybrid operation of the hybrid vehicle consists of the state of charge of a vehicle battery and / or a torque request. Method according to one of the preceding claims, characterized in that the separating clutch is a friction clutch or a combination of a friction clutch and a positive connection. Method according to one of the preceding claims, characterized in that the state of motion of the crankshaft and / or the element of the vehicle drive train, which is selectively coupled to the internal combustion engine via the disconnect clutch, consists of a speed and / or an oscillation state. Method according to one of the preceding claims, characterized in that the sensors for detecting the state of motion of the crankshaft and / or the element of the vehicle drive train, which is selectively connectable to the internal combustion engine via the disconnect clutch, are speed sensors. Method according to one of the preceding claims, characterized in that the element of the vehicle drive train, which is selectively coupled to the internal combustion engine via the disconnect clutch, is a rotor shaft of the electrical machine or an input shaft of a travel gear or an input shaft of a differential gear. Method according to one of the preceding claims, characterized in that the operating state of the hybrid vehicle for selecting the pattern for selective cylinder deactivation, the current firing order of the internal combustion engine and / or the starting position of the crankshaft of the stopped internal combustion engine and / or the current speed of the crankshaft of the internal combustion engine and / or of the vehicle drive train. Method according to one of the preceding claims, characterized in that the driving cycle influencing variables for the selection of the pattern for selective cylinder deactivation include the vehicle speed and / or the load and / or the accelerator pedal position.

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