DE102007009568A1 - Hybrid drive comprises electrical machine with drive shaft, where internal combustion engine is provided with another drive shaft, and both drive shafts are temporally coupled with one another - Google Patents

Abstract

The hybrid drive comprises an electrical machine (10) with a drive shaft (12). An internal combustion engine (20) is provided with another drive shaft (22), where both the drive shafts are temporally coupled with one another with a fixed speed ratio. The common position detecting devices (40,50) temporally detect the positions of both the drive shafts. Independent claims are also included for the following: (1) a method for detecting the positions of two drive shafts of an electrical machine (2) a method for operating a hybrid engine.

Description

State of the art

The Invention is based on parallel hybrid vehicles, in which a Electric engine via a clutch directly with an internal combustion engine connected is. The internal combustion engine has a transmitter wheel which the angular position of the crankshaft with a discrete resolution, usually 6 degrees, indicates. The electric machine comprises a further position sensor, due to the high dynamic requirements a short response time and provides a high resolution position signal.

The publication DE 10 303 392 A1 discloses a position sensor for a shaft in which the tooth position of a magnetic pulse wheel are scanned by means of magnetic scanning. The position wheel described there supplies angle or speed information with a resolution that depends on the tooth pitch, so that the angular resolution of the generated position signal is coarse and fraught with angle errors.

Disclosure of the invention

Of the Invention is based on the concept that position signal of the E-machine also for the combustion engine coupled with it to use. In this way, it is possible to switch to an encoder wheel on the internal combustion engine, which is used to control the internal combustion engine omitted become. In addition, by the position signal of the electric motor, the Position of the internal combustion engine without further aids with high Precision can be determined.

The inventive concept is further implemented by hybrid engines, in which the electric machine is temporarily, d. H. in certain operating conditions, with the internal combustion engine directly or via a constant Speed ratio is connected. In this case, in the operating state during which the electric machine with the Internal combustion engine via a constant speed ratio is coupled, the position signal of the electric machine verwen det. In Operating conditions in which no such connection between the combustion engine and the electric motor, the angle signal of the internal combustion engine via a secondary position sensor provided there be determined, these only meet the requirements must be required in such operating conditions are. Since the operating conditions in which no coupling between electric motor and combustion engine, none or only approximate or rough angle information of the internal combustion engine require the secondary position sensor can be simplified be provided.

Further the secondary position sensor can only be used when the internal combustion engine is not operated or idling, wherein in the active state of the internal combustion engine, the position sensor of E-machine is used because the internal combustion engine in the active state connected to the electric machine. In other words, for position detection of the internal combustion engine the common position sensor used when the internal combustion engine is active and with the electric machine is coupled. In passive state, d. H. when the internal combustion engine is off, or if this little or no mechanical Power generated, is only to control the internal combustion engine an approximately or with relatively high error tolerances Afflicted position signal necessary. This allows the secondary position sensor the internal combustion engine can be simplified.

A Transmitter wheel adaptation is when detecting the position of an internal combustion engine by means of a sender wheel necessary to compensate for the inaccuracies and to detect misfiring. The present invention However, allows operation of the hybrid engine without Geberrad- adaptation, since during certain operating conditions in which the misfire detection is required, the position the internal combustion engine by means of the common position sensor, which also detects the position of the electric machine can. An encoder wheel adaptation is therefore not necessary as a common Position sensor, preferably the position sensor of the electric machine, also be used for position detection of the internal combustion engine can. This makes it possible to dispense with an adaptation step, the makes the switching off of the internal combustion engine required. Thereby the operation of the hybrid drive is simplified.

The common position detecting device is preferably connected in a rotationally fixed ratio with the drive shaft of the electric motor. Further, the position detecting device may be connected in the same way with a shaft having at least temporarily a speed-fixed ratio with the electric machine, and to which the drive shaft of the internal combustion engine can be coupled. The speed-proof connection can be provided via a direct mechanical connection and / or via a non-shiftable clutch and / or via a transmission with a fixed speed ratio. The common position detecting device is mechanically connected to the drive shaft of the electric machine according to a first embodiment. This can be carried out by means of a transmitter wheel in the form of a gear or as a shaft, for example a flexible shaft. In a second embodiment, the common position detection device is elek trically and / or magnetically connected to the movement of the drive shaft of the electric machine and includes a sensor for detecting the current flow and / or the magnetic field in the electric machine.

The common position detection device may, for example, a Be sensor, the movement of a drive shaft over measures a mechanical connection, and the movement, for example scanned by means of optical, magnetic and / or Hall sensors. The movement of the drive shaft to be measured can be transmitted to a gear which is measured optically, magnetically or by Hall sensor. Furthermore, the mechanical movement can be passed on to a pin or gear be that has optical or magnetic characteristics. The reading can be done optically, ex. by means of a light barrier, and / or magnetic, for example by induction or by Hall sensor.

Further For example, the common position detecting device can be electric or be magnetically connected to the drive shaft. Here are the currents flowing in the electrical machine detected, with their course and / or their amplitude on the Speed and / or can be closed to the position. For example The electrical machine can be controlled with a power output stage which comprises a sense MOSFET transistor as a switching element, wherein the power section of these transistors is the electric machine controls and the scythe section into the electric machine flowing current. Alternatively you can Also shunt resistors are used in the current flow the electric machine are turned on.

To the One can be the current and / or the voltage of the drive windings be considered, for example by means of a shunt resistor, a sense MOSFET or by means of a Hall sensor, the magnetic field Measures, which is caused by the flow of electricity. On the other hand can the current or the voltage in the field winding are considered, For example, the voltage component, which is due to the inductive Linkage to the stator windings, d. H. With gives the drive windings. As a position signal can thus the edges and / or the amplitude of the voltage or the current the excitation coil are considered, for example, from the frequency of the flanks gives the speed of rotation and each flank approaching or removing an exciter pole indicates to a pole of the stator winding. Such Component te can, for example, via a shunt resistor be tapped in the excitation circuit. Alternatively, a Sense MOSFET can be used to drive the excitation winding, its sense output the flowing stream and thus the reproduces the stress component described above. Furthermore, the Using a shunt resistor or a Hall sensor possible, the conclusions on the through the exciter winding allow flowing current and the induced voltage component reflect the movement of the excitation winding relative to the Ständerwicklung reflects.

Preferably For example, the common position detecting device is a device for sensorless control of the electric machine, whereby "sensorless" here the lack of mechanical connection between sensor and shaft means. Such a sensorless control can, for example via the above-described current or voltage-related sampling of the Operation of the electrical machine may be provided. This can for example the drive signal are drawn in and / or controller signals, which are used to control a power level. There are Numerous algorithms known from such stream-related Sensor data determine the speed and / or the absolute angular position.

In One embodiment includes the common position detection device a sensor that passes through a specific winding position indicates, as well as another sensor, the rotational speed determined, for example, an occurrence frequency of edges in Current flow of the electric motor. The common position detection device can thus combine the information of both sensors and from this Close the combination to the absolute angle. In general For example, the common position detecting device may have a plurality of angle signals combine, for example, an absolute angle signal and a relative angle signal, being different angle signals from different sensors, in particular different types of sensors can come from. For example, can a mechanical sensor can be used which determines the exact passing time mechanically detected at a certain angular position, this information can be combined with a relative angle signal that off the electrical determination of the rotational speed, for example a current-related sensor, can be derived.

The underlying inventive concept is implemented by a hybrid drive with electric machine and internal combustion engine, which are coupled to each other at least in an operating state with a fixed speed ratio, wherein a common position detection device in this operating condition determines the angular position of the electrical rule machine and the internal combustion engine. For hybrid drives with elek trischer engine and internal combustion engine, the drive shafts are always firmly connected to each other, for example, directly, or via a transmission with a fixed speed ratio, the common position detection device can be used in all operating conditions. If a switchable coupling is arranged between the electric machine and the internal combustion engine, then the common position detection detects the position of the electric machine and of the internal combustion engine when they are connected to one another. When the electric machine is disconnected from the internal combustion engine via the shiftable clutch, the common position detection device determines the position data of the electric machine, wherein a secondary position sensor detects the movement of the internal combustion engine. Since with separate clutch the position data of the internal combustion engine must be supplied with lower accuracy, can be used as a secondary position sensor, a low-cost sensor device without affecting the operation of the internal combustion engine.

The underlying inventive concept is further by a method implemented for position detection, in which also a common Position detecting device, the angular position of the engine as well as the electric machine collectively when these together are coupled. As already described, this coupling can be permanent be provided or via a switchable coupling, wherein the common position detecting device is the angular position the electric machine and the internal combustion engine only together detected when they are coupled together. In operating conditions or during time intervals in which the electrical Machine is separated from the internal combustion engine is sufficient a secondary position sensor for recording the position data of the internal combustion engine used for the operation of the internal combustion engine sufficient in a separate state of the electric machine is. Furthermore, the underlying inventive concept of a method for operating a hybrid engine implemented in the the electric machine at least temporarily with the internal combustion engine coupled and a common position detection device, preferably the position sensor of the electric machine, the Position of the electric machine and the position of the internal combustion engine recorded simultaneously.

The Operating conditions in which the internal combustion engine with the coupled electrical machine, or the operating conditions, in which the electric machine and the internal combustion engine from each other can be separated from the driving behavior and the power requirement result. With regard to the inventive concept is between Operating states divided, the first time intervals define where the combustion engine with the electric machine is coupled. Operating conditions in which the electrical Engine is disconnected from the internal combustion engine, enter second Time intervals. The coupling or decoupling is due to the handling conditional, may be regular or irregular, and is also dependent on the power requirement. Further Sizes that indicate the timing of the coupling or decoupling can affect tank contents, still remaining Distance, desired speed / acceleration, Accumulator capacity and accumulator state of charge and the Power requirements of other consumers, such as the headlamp, be.

In This application is intended to "mechanical coupling" the carry a rotational movement, for example, the rotational movement of the Drive shaft of the electric machine or the rotational movement the drive shaft of the internal combustion engine. As a clutch with fixed Speed ratio are combinations of clutches and gears designated, the gearbox a fixed speed ratio between input and output and the couplings also a fixed ratio between input speed and output speed have, for example, elastic couplings or couplings with constant slip. As speed-proof coupling is here in Generally referred to a clutch whose output power in fixed relation to the input power.

For this Distinguishable are separable couplings, which are also in combination provided with gearboxes with fixed speed ratio can be. Separable couplings are switchable couplings, their mechanical transfer between input and output can be influenced from the outside. examples for Switchable clutches are externally switched clutches, for example Disc clutch, magnetic clutch, cone clutch or dog clutch or gear coupling. The motion transfer between input and output of a clutch may also be self-switching and thus be influenced only conditionally from the outside. Examples of this are centrifugal clutch whose movement transfer ratio depends on the speed, the one-way clutch whose motion transfer depends on the speed difference between input and output, and the slip clutch whose motion transfer depends of the torque difference between input and output.

Brief description of the drawings

embodiments The invention is illustrated in the drawings and in the following Description explained in more detail.

It demonstrate:

The 1 a schematic diagram of a hybrid drive according to the invention, wherein the drive shaft of the electric machine and the drive shaft of the internal combustion engine are permanently coupled together in a fixed speed ratio.

The 2 an operating diagram of the hybrid drive according to the invention, in which an electric machine with an internal combustion engine via a switchable coupling are interconnected.

embodiments

The in 1 shown hybrid drive includes an electric machine 10 with a first drive shaft 12 and an internal combustion engine 20 with a second drive shaft 22 wherein the drive shaft of the electric machine is coupled directly to the drive shaft of the internal combustion engine. To connect the two drive shafts, a speed clutch, for example a flange coupling or a face gear coupling, is provided. Alternatively, the connection 30 also be a positive coupling. In a further, non-manufactured embodiment, the two drive shafts for speed adaptation are connected to a transmission which couples the electric machine with the internal combustion engine via a permanent, unchangeable speed ratio. Furthermore, as an alternative or in combination thereto, an elastic coupling can be provided between the two drive shafts which can not be shifted, for example for damping speed oscillations or as torque-dependent securing.

In the 1 illustrated embodiment allows the use of only one common position detection device 40 respectively. 50 since the position of the electric machine can be used to directly and unambiguously deduce the position of the internal combustion engine, and vice versa, even if a transmission with a fixed speed ratio is provided between the electric machine and the internal combustion engine.

In the in 1 In the illustrated embodiment, the electric machine comprises a motion sensor, which also in another embodiment of the hybrid drive according to the invention on the internal combustion engine 20 or may be provided on the second drive shaft.

The position detection device 40 generally includes two parts that move relative to each other. Here, a fixed sensor, such as a magnetic sensor, an electromechanical sensor, an optical sensor or a magnetic sensor are fixed and detect the movement of a rotating with the drive shaft part. Alternatively or in combination with this, a sensor 50 used, which detects the flow of current to the electric machine. In the in 1 In the illustrated embodiment, therefore, a shunt resistor is used, at which a voltage drops, which is proportional to the current flow to the electric machine. This voltage can be evaluated in terms of their shape and / or their amplitude. The current flowing to the electrical machine current can also be measured via sense MOSFET or other semiconductor devices, for example via Hall sensors that detect the magnetic field, which results from the current flowing to the electric machine.

The position detection device 50 may refer to the current that flows into one or more stator windings of the electrical machine. Alternatively, the position detection device 50 refer to current that flows into the excitation winding, for example, to determine the voltage component, which is due to the induction of the stator windings back into the regulator winding. A common position detecting device which measures the current flow within or about the electric machine may alternatively be a position detecting device 40 be used, which determines the position by means of sensor. Furthermore, the movement sensor arranged on the electric machine can 40 be a sensor that outputs an absolute angle signal, for example, when the drive shaft or part of the rotor passes through a certain angular position, for example 0 °. In combination, a relative position detection device can then be used 50 used, which determines the angular velocity. The relative and absolute position recognizer signals may then be combined and together form an accurate absolute angle signal for each angular position.

The in 1 shown hybrid drive further includes a controller 60 that the operation of the internal combustion engine 20 as well as the operation of the electrical machine 10 controls. For example, the controller 60 Ignition signals for the internal combustion engine 20 provide and / or provide the electrical machine with electrical drive power. Here, the controller 60 provide the current for the excitation winding and the current for the stator windings. Alternatively, the controller 60 also provide control signals for the field winding and / or for the stator windings, wherein a downstream power amplifier converts one of the two signals or both signals into currents flowing in the respective windings.

According to one embodiment of the invention the electric machine 10 a DC motor whose power can be controlled via amplitude and / or pulse wave modulation. To adjust the rotational speeds, the electric machine may have a suitable number of poles. Further, a speed adjustment between the electric machine and the internal combustion engine by means of a transmission, for example by means of a gear transmission is possible to connect the electric machine and the internal combustion engine with a common drive shaft.

Preferably, the electric machine 10 a synchronous machine whose rotor winding is supplied with an excitation current, and whose stator winding is supplied to generate a rotating field with a stator current. For position detection, the profile of the control of individual stator winding sections, the frequency and / or the phase position of the stator current can be tracked. Furthermore, alternatively or in combination with this, the armature reaction can be detected, for example by means of a current sensor (shunt, sense section of a MOSFET or the like) in the supply circuit of the stator winding. Instead of a field winding preferably a permanent magnet is used.

The combined drive power of the electric machine and the internal combustion engine is by means of a drive shaft 80 to a drive connection 70 coupled. The mechanical power in the form of rotational energy is thus forwarded by the hybrid drive in a driven direction A.

Although in the 1 two position detection devices 40 . 50 1, another embodiment, not shown, of the invention comprises only one of the position recognition devices 40 . 50 In this case, these position detecting devices detect the angular position of the first drive shaft and the second drive shaft directly or indirectly with high resolution. In a further embodiment of the hybrid drive according to the invention, a position detection device is provided neither on the electric machine nor on the internal combustion engine. Instead, the position is provided solely via the drive or current signals of the electric machine. Alternatively, the position detection device may comprise a simple absolute angle detection sensor attached to one of the drive shafts 12 . 22 , on the drive shaft 80 , and / or is mounted on the electric machine or on the internal combustion engine and is able to detect a single absolute angular position, for example a certain angular passage or the passage through the horizontal, with high precision and to generate a corresponding signal. Preferably, this absolute angle signal is sent to the controller 60 directed, which in combination with a relative Winkelelsig signal with high resolution can determine the exact position of the first drive shaft and thus simultaneously the second drive shaft.

The 2 shows a further embodiment of the hybrid drive according to the invention. As in the 1 The embodiment shown in FIG 2 illustrated embodiment, an electrical machine 110 , an internal combustion engine 120 wherein the electric machine is a first drive shaft 112 and the internal combustion engine, a second drive shaft 122 includes. The movements of both drive shafts can be combined and via an output shaft 180 an output conclusion 170 be supplied. The kinetic energy is dissipated in one direction A 'from the hybrid drive.

Furthermore, the in 2 shown hybrid drive a controller 160 using a common position detection device 150 connected is. The common position detection device 150 determines the position of the electric machine 110 or the first drive shaft 112 ,

Unlike in 1 illustrated embodiment, the first drive shaft is not permanently connected in a fixed speed ratio with the second drive shaft. Rather, both drive shafts by means of a switchable coupling 190 be interconnected, depending on the desired operating condition. The switchable clutch 190 is via a line with the controller 160 connected and controlled by this.

For example, in an operating mode in which the internal combustion engine is switched off and only the electric machine generates drive power, the first drive shaft is decoupled from the second drive shaft. In this case, the output shaft 180 only with the first drive shaft 112 , ie connected to the electrical machine. For this operating state, in which the internal combustion engine is not connected to the electric machine, detects a secondary position sensor 155 the position of the second drive shaft, ie the angular position of the internal combustion engine 120 , Preferably, the angle encoder 155 with the controller 160 connected to provide this data, which includes information about the angular position. Preferably, the secondary position sensor 155 an absolute angle sensor with low resolution, for example, a stepwise resolution of 3 °, 5 °, 6 °, 10 °, 12 °, 15 ° or 30 °. In a further embodiment, the secondary position sensor is set up to detect angular positions that are necessary for starting the internal combustion engine 120 required are.

The second drive shaft 122 can also be connected to a freewheel clutch that does not transmit motion when the speed of the second Drive shaft less than the speed of the first drive shaft 112 is, however, the drive power from the internal combustion engine 120 to the first drive shaft or to the drive shaft 180 transmits, if the internal combustion engine has a higher speed than the electric machine. In this way, the internal combustion engine is decoupled to prevent portions of the kinetic energy generated as friction and / or flow losses in the internal combustion engine 120 be converted into heat. Preferably, the one-way clutch is permanently lubricated, that is equipped with a lubricating film regardless of the operation of the internal combustion engine.

The common position detection device 150 determines the angular position of the first drive shaft and the second drive shaft when the first drive shaft is coupled to the second drive shaft. If the first drive shaft is separated from the second drive shaft, for example to avoid friction losses in the internal combustion engine, a secondary position sensor takes over the function for the internal combustion engine 120 However, with regard to the accuracy of the secondary position sensor only low demands are made, which are sufficient for starting the internal combustion engine and for a controlled operation of the internal combustion engine well below its maximum power.

Instead of or in combination with a common position detection device 150 that between the controller 160 and the electric machine 110 is arranged, a position detecting device may be provided directly to the electric machine or to the first drive shaft, which detects the movement of the drive shaft by means of an optical sensor, magnetic sensor or Hall sensor. As in the 1 illustrated embodiment, an absolute angle encoder directly to the first drive shaft or on the drive shaft 180 be provided while a relative angle encoder with high accuracy and resolution in the current path between the electric machine 110 and control 160 is provided. In combination, these two sensors provide the common position detection device, with the controller 160 the signals combined in a suitable manner.

Further can signals a sensorless regulation of the electrical Machine for position determination and thus as a common position detection device where the controller is set up, algorithms to carry out, which consists of signals of the sensorless control Calculate position signals.

As a switchable clutch 190 between the first drive shaft 112 and second drive shaft 122 can be used a non-positive and externally connected clutch, for example, a disc clutch, a disc dry clutch, a double clutch, a multi-plate clutch, a magnetic clutch, or a cone clutch. Furthermore, non-positive and self-switching clutches as a clutch 190 be used, for example, a centrifugal clutch, a one-way clutch or a slip clutch. Here, the coupling state is not by the controller 160 determinable.

Furthermore, external and external couplings can be used, in turn, by the controller 160 can be switched, for example, a dog clutch or a toothed clutch.

When common position detection device may be a shunt resistor, a sense MOSFET and / or a Hall sensor can be used. Of the Shunt resistor or the sense MOSFET can with a or a plurality of stator windings and / or with the field winding be coupled. Furthermore, such current sensors in the circuit of the exciter winding and in the circuit of the stator windings be provided. In addition, control signals of the controller, the specify an angle setpoint, used for position detection become. The Hall sensor can be used to measure the magnetic field of the supply line to the excitation winding and / or the magnetic field of the supply line to the Stator windings are used. Furthermore, the Hall sensor also in the stator windings and / or in the field winding be provided to the respective field generated by the windings capture. Instead of a Hall sensor can also be an induction coil be used to from the voltage induced in the coil to be able to close the angle course. Further can also be used as a generator powered electric motors (For example, low-power DC motors) for position detection be used, whose shaft with the electric machine, the Internal combustion engine, the first drive shaft, the second drive shaft or the output shaft is connected, for example via a gearbox or indirect way. In a further embodiment According to the invention, the controller further detects the ignition timing suitable signals, for example by detecting the ignition voltage or the ignition control voltage.

QUOTES INCLUDE IN THE DESCRIPTION

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Cited patent literature

• - DE 10303392 A1 [0002]

Claims (10)

Hybrid drive, which is an electric machine ( 10 . 110 ) with a first drive shaft ( 12 . 112 ) and an internal combustion engine ( 20 . 120 ) with a second drive shaft, wherein the first and the second drive shaft ( 22 . 122 ) are coupled together at least temporarily with a fixed speed ratio, characterized by a common position detection device ( 40 . 140 . 50 ), which at least temporarily the position of the first drive shaft ( 12 . 112 ) and the position of the second drive shaft ( 22 . 122 ) detected. Hybrid drive according to claim 1, wherein the first and the second drive shaft ( 12 . 22 ) are permanently coupled together in a fixed speed ratio. Hybrid drive according to claim 2 with a non-shiftable clutch ( 30 ), wherein the first and the second drive shaft ( 12 . 22 ) directly via the non-shiftable clutch ( 30 ) are coupled together. Hybrid drive according to claim 1, which is arranged, the first and the second drive shaft ( 22 . 122 ) at a fixed speed ratio during first time intervals having selectable starts and selectable ends, and not coupling at a fixed speed ratio during second time intervals having selectable starts and selectable ends. Hybrid drive according to claim 4, comprising a shiftable clutch ( 190 ), wherein the first and the second drive shaft ( 112 . 122 ) via the switchable coupling ( 190 ) whose operation defines the first and second time intervals. Hybrid drive according to claim 4, comprising a secondary position sensor ( 155 ), which is arranged, the position of the first drive shaft ( 112 ), wherein the common position detection device ( 150 ), during the second time intervals the position of the second drive shaft ( 122 ) capture. Method for detecting the position of a first drive shaft ( 12 . 112 ) an electric machine ( 10 . 110 ) and the position of a second drive shaft ( 22 . 122 ) of an internal combustion engine ( 20 . 120 ), wherein the electric machine ( 10 . 110 ) and the internal combustion engine ( 20 . 120 ), at least temporarily in direct coupling ( 30 . 190 ) are operated in combination with one another at a constant speed ratio in a hybrid drive, characterized by providing a common position detection device ( 40 . 140 . 50 ) and, while operating the electric machine ( 10 . 110 ) and the internal combustion engine ( 20 . 120 ) in direct coupling with each other, collectively detecting the position of the first drive shaft ( 12 . 112 ) and the position of the second drive shaft ( 22 . 122 ) by means of the common position recognition device ( 40 . 140 . 50 ). Method according to claim 7, wherein the electric machine ( 10 ) and the internal combustion engine ( 20 ) are arranged to be permanently operated in direct coupling with each other at a constant speed ratio in a hybrid drive, and the common detection comprises detecting the position of the first drive shaft ( 12 ) and the second drive shaft ( 22 ). Method according to claim 7, wherein the electric machine ( 110 ) and the internal combustion engine ( 120 ) are arranged to operate in combination with each other at a constant speed ratio during first time intervals having selectable starts and selectable ends, and are arranged to be separated from one another during second time intervals having selectable beginnings and selectable ends wherein the step of jointly detecting is performed during the first time intervals and the method further comprises detecting, during the second time intervals, the position of the second drive shaft (10). 122 ) by means of the common position detection device ( 150 ) and the position of the first drive shaft ( 12 . 112 ) by means of a secondary position sensor ( 155 ). Method for operating a hybrid engine comprising an electric machine ( 10 . 110 ) with a first drive shaft ( 12 . 112 ) and an internal combustion engine ( 20 . 120 ) with a second drive shaft ( 22 . 122 ), with the step of at least temporarily coupling the first drive shaft ( 12 . 112 ) with the second drive shaft ( 22 . 122 ), characterized in that the method further comprises jointly determining, while the first drive shaft with the second drive shaft ( 22 . 122 ), the position of the first and the second drive shaft ( 22 . 122 ) by means of a common position recognition device ( 40 . 140 . 50 ).