DE102020208181A1 - Method for operating a hybrid vehicle during a special operating trip, control unit and hybrid vehicle - Google Patents

Abstract

The present invention relates to a method for operating a hybrid vehicle (100) in a special operating mode (SB), the hybrid vehicle (100) having a drive train (1) comprising an internal combustion engine (V), an electrical machine (E1, E2) and a Has output and the drive train (1) is set up to _{variably translate a power (P VKM} ) delivered by the internal combustion engine (V) to the output, the method comprising:
- Detecting a drive power requirement (P _des ) for driving the hybrid vehicle (100) in accordance with a driver's request;
- Operating the internal combustion engine (100) in an operating range (T) optimized for the special operating mode (SB); and
- Implementation of the drive power requirement (P _des ) by means of the drive train (100), the internal combustion engine (V) being operated within the optimized operating range (T).

Description

The invention relates to a method for operating a hybrid vehicle during a special operating mode, a control device and a hybrid vehicle.

US 6,359,404 B1 describes a control device comprising a requested torque calculator that calculates a torque required to drive a hybrid vehicle, and a torque control device that controls a torque generated by a motor and a torque generated by an electric motor of the hybrid vehicle based on the requested torque , having. The torque control device controls the electric motor to generate a torque obtained by subtracting a torque to be generated by the motor from the requested torque. According to this control device, the electric motor is controlled so that it generates the missing (additional) torque when responsiveness to a change in the gear ratio of the transmission is poor and the torque generated by the motor becomes lower than the requested torque, and smooth acceleration of the Vehicle can be carried out. Furthermore, the torque control device can comprise a device for limiting the motor torque, which device limits the torque to be generated by the motor in accordance with a predetermined condition. Thus, the engine torque limiting device can limit the torque to be generated by the engine when the temperature of a catalytic converter provided in the exhaust system of the engine is higher than a predetermined temperature.

JP 2016037252A describes a hybrid vehicle having a drive system that includes an internal combustion engine and a motor. A first clutch is provided between the internal combustion engine and the motor. Furthermore, a continuously variable transmission is provided between the internal combustion engine and drive wheels. In the hybrid vehicle, a catalyst for purifying the exhaust gases from the internal combustion engine and a catalyst warm-up control device for heating the catalyst to the activation temperature by the internal combustion engine are provided. The catalyst warm-up control means controls the engine torque according to the driving torque required by the driver during the catalyst warm-up operation in which the hybrid vehicle is running while the first clutch is slipped and the catalyst for controlling the engine is warmed up, and also maintains the slipped state of the first clutch by speed control of the continuously variable transmission upright.

JP4967898B2 describes a hybrid vehicle that has an internal combustion engine having a catalytic device, a generator that can generate power by the power of the internal combustion engine and charge a battery with the power obtained by the generation, and an electric motor that can generate power depending on the discharge power discharged from the battery can deliver, includes. A control device for the hybrid vehicle comprises first specific means for identifying the power obtained by the generation during the warm-up phase of the catalytic converter device, first setting means for setting an upper limit of the discharge power on the basis of the identified power, and first control means for controlling the internal combustion engine and the electric motor such that the discharge power is less than or equal to the set discharge power limit.

In previous catalyst heating processes by operating an internal combustion engine in idle mode or through torque band catalytic converter heating, comparatively high emission values, comparatively high fuel consumption and / or comparatively long heating processes can occur. Furthermore, the heating process can also be interrupted if a possible drive requirement has to be met by shifting the operating point of the internal combustion engine.

The object of the present invention is to provide an improved method for operating a hybrid vehicle in special operating modes, an improved control device and an improved hybrid vehicle.

This object is achieved by the method according to claim 1, the control device according to claim 9 and the hybrid vehicle according to claim 10.

Further advantageous embodiments of the invention emerge from the subclaims and the following description of preferred exemplary embodiments of the present invention.

• - Erfassen einer Antriebsleistungsanforderung zum Antreiben des Hybridfahrzeugs gemäß einem Fahrerwunsch;
• - Betreiben der Verbrennungskraftmaschine in einem optimierten Betriebsbereich; und
• - Umsetzen der Antriebsleistungsanforderung mittels des Antriebsstrangs, wobei die Verbrennungskraftmaschine innerhalb des optimierten Betriebsbereichs betrieben wird.

A first aspect of the present disclosure relates to a method for operating a hybrid vehicle in a special operating mode, the hybrid vehicle having a drive train that has an internal combustion engine, an electric machine and an output, and the drive train is set up to transfer power output by the internal combustion engine to the output to translate variably, the procedure comprising:

• - Detecting a drive power request for driving the hybrid vehicle according to a driver's request;
• - Operating the internal combustion engine in an optimized operating range; and
• Implementation of the drive power requirement by means of the drive train, the internal combustion engine being operated within the optimized operating range.

The hybrid vehicle may have a series or a parallel hybrid arrangement.

The drive train of the hybrid vehicle is set up to convert the power output by the internal combustion engine (internal combustion engine power) at least partially or even completely variably to the output. A torque generated by the internal combustion engine and / or a speed of the internal combustion engine can be translated. "Translate" means that the internal combustion engine power can be transferred to the output in certain ratios. In some embodiments, the variable gear ratio, that is to say the transmission ratio, can be freely selected. The translation can be done by a suitably set up gear arrangement. Alternatively or in addition, the translation can also include that the internal combustion engine power is converted at least into electrical power by means of a generator, which is then at least partially used to drive the electrical machine operated as a drive motor. The electrical power can also be used to charge an electrical storage device of the hybrid vehicle that is connected to the electrical machine.

The output of the drive train usually includes the wheels of the hybrid vehicle. In this way, a (drive) power generated by the internal combustion engine can be transmitted to the output in an at least partially freely adjustable manner. "Freely adjustable" here means that the power of the internal combustion engine can be transmitted to the output without a fixed gear ratio.

Examples of hybrid vehicles that enable a variable gear ratio are a serial hybrid, a serial-parallel hybrid, an eCVT hybrid, or a parallel hybrid with mechanical CVT . Further examples are parallel hybrids with stepped gear arrangements, which can represent a variable ratio, or at least transfer part of the power of the internal combustion engine independently of the fixed ratio, since there is another electric machine on the wheel axle side. Examples of this are a parallel P0-P3 hybrid (with a belt starter generator (P0) and an electric machine (P3) on the front wheel axle), a P0 hybrid with an electric machine on the rear wheel axle (P4), or a P2 parallel hybrid with an additional Electric machine provided on the rear wheel axle side (P4). In other examples, the first-mentioned hybrid arrangements with variable transmission can also have an electrical machine additionally provided on the rear wheel axle side.

The electrical machine can be operated as a motor or as a generator. For this purpose, the electrical machine is coupled to the electrical storage device. In some embodiments, the electrical machine is also coupled to the internal combustion engine, so that the electrical machine can convert the internal combustion engine power into electrical power in generator mode.

The drive power is the power that is provided by the drive train and used to drive the hybrid vehicle. The drive power requirement is a driving speed desired by a driver of the hybrid vehicle, which can be derived, for example, from an actuation and / or position of an accelerator pedal of the hybrid vehicle.

The method is aimed at operating the hybrid vehicle in a special operating mode. Special operating modes of the hybrid vehicle, such as catalytic converter heating, can regularly only be implemented in a sub-range of the regular operating range of the internal combustion engine due to the limited stability of fuel combustion in the internal combustion engine.

The internal combustion engine is operated in the operating range optimized for the special operating mode. The optimized operating range comprises a large number of optimized operating points. This refers to the operating points of the internal combustion engine, an operating point being defined by the torque generated by the internal combustion engine and its speed. The internal combustion engine is thus operated at an optimized operating point, the optimized operating point being selected from a large number of operating points optimized for the special operating mode. In some embodiments, the optimized operating range can be a single operating point. In other embodiments, the optimized operating range can be a (characteristic) line or trajectory in a characteristic diagram of the internal combustion engine. In further embodiments, the optimized operating range can include a range around the previously described line in the engine map of the internal combustion engine.

Each operating point of the multitude of optimized operating points is an operating point optimized for a corresponding performance of the internal combustion engine. Depending on the special operating mode, the optimized operating range can be determined according to corresponding optimization criteria. For example, the ratio of exhaust gas enthalpy to raw emissions (e.g. HC raw emissions and / or NOx raw emissions) can be used as an optimization criterion for the above-mentioned catalyst heating as a special operating mode. As a rule, the engine map and the optimized operating range are determined empirically. In some embodiments, the optimized operating range and the map can also be derived from models, simulations, mathematical formulas, etc.

The drive power requirement is implemented by means of the drive train. In other words, the internal combustion engine, the electric machine and the variable ratio through the drive train interact in such a way that the drive power requirement of the driver, e.g. B. the desired vehicle speed is implemented. While the drive power requirement is being implemented, the internal combustion engine is operated in the optimized operating range. Depending on the drive power requirement, it can happen that the internal combustion engine operated in the optimized operating range delivers a power (internal combustion engine power) that is higher or lower than the drive power requirement. However, the difference between the drive power requirement and the internal combustion engine power can be compensated for by the variable ratio of the drive train and / or by an electrical power reserve of the drive train, which is made available by the electrical machine and an electrical storage device. The electrical power reserve can include at least one of positive and negative power reserves. "Positive power reserve" means that an (electrical) power can be provided in addition to the internal combustion engine power, and "negative power reserve" means that the internal combustion engine power transferred to the output can be reduced, whereby the operating point of the internal combustion engine is not influenced in any case.

Thus, in order to implement the drive power requirement, the internal combustion engine is operated in the optimized operating range, the operating point of the internal combustion engine shifting within or along the optimized operating range depending on the drive power requirement. To achieve the drive power requirement, the internal combustion engine power is combined, if necessary, with the electrical power reserve.

The above method can thus ensure that the internal combustion engine is operated in an operating range optimized for the special operating mode and that the driver's drive power requirement is met at the same time.

In one embodiment, in which the special operating mode is the catalyst heating mode and the optimization criterion is the ratio between the exhaust gas enthalpy and the raw emissions, it can be ensured that a catalyst heating mode is enabled in which (raw) emissions and / or fuel consumption are at least partially reduced can or even be optimally adjusted and at the same time the drive power requirement is ensured.

• - Übersetzen der von der Verbrennungskraftmaschine abgegebenen Leistung zur Umsetzung der Antriebsleitungsanforderung; und
• - Betreiben der elektrischen Maschine in einem Motor- oder Generatormodus zum Erreichen der Antriebsleistungsanforderung.

In some embodiments, the implementation of the drive power requirement by means of the drive train can further comprise at least one of the following:

• - Translate the power delivered by the internal combustion engine to implement the drive line request; and
• - Operating the electrical machine in a motor or generator mode to achieve the drive power requirement.

As described above, the translation of the torque or the internal combustion engine power can take place through the variable translation. In some embodiments, the translation can take place via a correspondingly configured gear arrangement which the drive train has. The gear arrangement can, for example, be a planetary gear, a double clutch gear and / or a continuously variable transmission CVT ) include.

Alternatively or additionally, the electric machine can be operated in a motor or generator mode in order to implement / achieve the drive power requirement. In a case in which the engine power is insufficient to implement the drive power requirement, the electric machine can be used as a drive motor in order to close the gap between the engine power and the drive power requirement. In another case in which the internal combustion engine power is higher than the drive power requirement, the electric machine can be used as a generator which at least partially converts the internal combustion engine power into electrical power. Thus, for example, the electrical storage device can be charged by the power of the internal combustion engine will. Correspondingly, the internal combustion engine power can thus be at least partially transferred to the output.

In further embodiments, the power from the internal combustion engine can alternatively or additionally be converted at least partially into electrical power by a further electrical machine and converted back into mechanical power (at a different speed) by the electrical machine. A correspondingly designed drive train can thus also represent a variable ratio. For example, such a variable translation can be implemented by means of a serial hybrid arrangement.

Thus, by means of the drive train described above, the internal combustion engine can be operated in the special operating mode within the optimized operating range and, at the same time, meet the drive power requirement of the driver.

In further embodiments, the optimized operating range can include an optimal operating point at a specific output of the internal combustion engine, i. E. H. an optimal operating point for the specific power, and ancillary optimized operating points for further power of the internal combustion engine. In other words, the optimized operating range comprises an absolute optimum for the specific performance and a corresponding local optimum for every other performance. The optimal operating point fulfills the above-mentioned optimization criterion best, whereas the ancillary optimized operating points or local optima fulfill the optimization criterion comparatively less well than the optimal operating point. In some embodiments, the situation is such that the greater the distance between the optimal operating point and one of the secondary optimized operating points, the worse the optimization criterion is met. What is meant here is the distance between the operating points in the engine map.

Thus, in some embodiments, an operating point within the optimized operating range can be selected as a function of the drive power requirement, taking into account the absolutely optimal operating point and the additional, optimized operating points.

In other embodiments, the optimized operating range can lie within a minimum power limit and a maximum power limit for the special operating mode and / or within a minimum speed and a maximum speed for the special operating mode. In other words, the optimized operating range can have a minimum and a maximum power limit and / or a minimum and a speed limit. The power and speed limits ensure that no higher or lower power or speed of the internal combustion engine is set that would lead to the special operating mode being exited. In other words, these limits ensure that the hybrid vehicle and the internal combustion engine are operated within the operating range (of the internal combustion engine) for the special operating mode. A power difference between the internal combustion engine power (which results from compliance with the power and / or speed limit) and the drive power requirement can be served by the electrical power reserve.

• - Verschieben eines Betriebspunkts der Verbrennungskraftmaschine innerhalb des optimierten Betriebsbereichs in Abhängigkeit einer Leistungsreserve des Antriebsstrangs, wobei die Leistungsreserve eine elektrische Leistungsreserve, die durch die elektrische Maschine und einen elektrischen Speicher zur Verfügung gestellt wird, und/oder eine verbrennungsmotorische Leistungsreserve, die durch ein Momentenband um den optimierten Betriebsbereich zur Verfügung gestellt wird, aufweist.

In some embodiments, operating the internal combustion engine within the optimized operating range may further include:

• - Shifting an operating point of the internal combustion engine within the optimized operating range as a function of a power reserve of the drive train, the power reserve being an electrical power reserve made available by the electrical machine and an electrical storage device, and / or an internal combustion engine power reserve that is generated by a torque band the optimized operating range is made available.

The torque band is a minimum (lower) and a maximum (upper) torque limit for the torque generated by the internal combustion engine, the torque band extending along the optimized operating range. In some embodiments, the torque band can be designed as a function of the speed. This means that the minimum and maximum torque limit can be determined differently for each speed within the optimized operating range. The drive power requirement can be partially covered by the internal combustion engine power reserve, so that little or no speed change is required on the internal combustion engine.
Furthermore, the power reserve can fall back on the electrical power reserve or on the internal combustion engine power reserve or on a combination of the electrical and internal combustion engine power reserve.

If there is now a large power reserve, the internal combustion engine can be operated over a comparatively long period of time at a comparatively better optimized operating point at which the internal combustion engine power is reduced by the power reserve of the Powertrain is supported. If the power reserve now decreases (e.g. due to a decreasing state of charge of the electrical storage device), the power reserve can only support the internal combustion engine to implement the drive power requirement for a comparatively short period of time. Consequently, the internal combustion engine output is increased or decreased by shifting the operation of the internal combustion engine from the comparatively better optimized operating point to a comparatively poorer optimized operating point (within the optimized operating range). The internal combustion engine power is thus at least approximated to the drive power requirement, so that less power reserve is used to achieve the drive power requirement.

If there is now a small power reserve, the internal combustion engine can be operated over a comparatively short period of time at a comparatively better optimized operating point, at which the internal combustion engine power is supported by the power reserve of the drive train. As a result, the procedure is as above and the internal combustion engine power is increased or decreased by shifting the operation of the internal combustion engine from the comparatively better optimized operating point to a comparatively poorer optimized operating point (within the optimized operating range). The internal combustion engine power is thus at least approximated to the drive power requirement, so that less power reserve is used to achieve the drive power requirement.

By shifting the operating point within the optimized operating range as a function of the power reserve of the drive train, the internal combustion engine can be operated particularly well in the optimized operating range B. Temperature) of the electrical machine can be taken into account.

In addition, short and / or small changes in the drive power requirement can be served by the power reserve, so that a shift in the operating point can be delayed or even avoided. As a result, the internal combustion engine can be operated longer at a better optimized operating point. Furthermore, the power reserve enables short and small changes in the drive power requirement to be debounced, which would otherwise lead to a shift in the operating point.

In further embodiments, the internal combustion engine can be operated as a function of an average drive power requirement. “Average drive power requirement” means that the drive power requirement can be averaged over a predetermined period of time; H. an average drive power requirement over the predetermined period of time. For example, these predetermined time periods can be up to 120 seconds. The internal combustion engine can thus be operated within the optimized operating range as a function of the average drive power requirement. A power difference between the (actual) drive power requirement and the average power requirement can be served by the power reserve of the drive train described above. As a result, the internal combustion engine can be operated longer at a better optimized operating point. Since the internal combustion engine remains in an operating state for a longer period, unsteady operation of the internal combustion engine can also be at least partially avoided.

In some embodiments, the special operating mode may include a catalyst heating operation of the hybrid vehicle. For example, the internal combustion engine can only be operated in part of its regular operating range in the catalytic converter heating mode due to the limited stability of the combustion. Furthermore, the catalytic converter heating mode is used to condition an exhaust gas aftertreatment and is therefore particularly sensitive to raw emissions, especially if the exhaust gas aftertreatment is not yet ready for operation and convertible. Leaving the special operating mode by leaving the corresponding operating range of the internal combustion engine can thus lead to impermissibly high emissions.

A second aspect of the present disclosure relates to a control device which is set up to carry out a method according to one of the embodiments described above.

A third aspect of the present disclosure relates to a hybrid vehicle with the control device described above. The hybrid vehicle is set up and designed to carry out a method according to one of the embodiments described above.

• 1A-C verschiedene Konfigurationen für einen Antriebsstrang eines Hybridfahrzeugs;
• 2A-C weitere verschiedene Konfigurationen für den Antriebsstrang des Hybridfahrzeugs;
• 3 ein Blockdiagram für eine schematische Darstellung des Hybridfahrzeugs;
• 4A, 4B schematisch Kennfelder einer Verbrennungskraftmaschine des Hybridfahrzeugs; und
• 5 ein Verfahren gemäß einer Ausführungsform.

Embodiments of the invention will now be described by way of example and with reference to the accompanying drawings. It shows:

• 1A-C various configurations for a hybrid vehicle powertrain;
• 2A-C other different configurations for the powertrain of the hybrid vehicle;
• 3 a block diagram for a schematic representation of the hybrid vehicle;
• 4A , 4B schematic maps of an internal combustion engine of the hybrid vehicle; and
• 5 a method according to an embodiment.

1A-C and 2A-C show exemplary configurations of a drive train 1 of a hybrid vehicle 100 , being the powertrain 1 is set up, a mechanical power of the internal combustion engine V (internal combustion engine power) to be variably translated to an output or, in other words, to be variably transmitted. The output can be wheels R. of the hybrid vehicle 100 include. In 1A-C and 2A-C Structurally and / or functionally similar components are identified with the same reference symbols.

1A shows the powertrain 1 with a serial-parallel hybrid arrangement. The powertrain 1 has an internal combustion engine V , a first and a second electrical machine E1 , E2 that with an electrical storage IT connected, a clutch K and a final drive A. on.

The internal combustion engine V can be designed as a gasoline or diesel engine and is via the clutch K with the axle drive A. connectable connected. With the clutch K can the internal combustion engine V with the axle drive A. be coupled or from the axle drive A. be decoupled. The internal combustion engine V is with the first electric machine E1 via an optional first translation facility T1 connected. The first translation facility T1 is set up to at least partially transfer the internal combustion engine power to the first electrical machine E1 transferred to. The electric machine 1 can be operated as a generator, so that the internal combustion engine V Mechanical power produced by the electrical machine E1 can be converted into electrical power. The electrical power can be used to charge the electrical storage device IT be used. The second electric machine E2 can be used as a motor to drive the hybrid vehicle. The electrical machine relates to this E2 from the electrical storage IT electrical power and converts it into mechanical power, which is then generated by means of an optional second translation device T2 on the axle drive A. and thus on the wheels R. for driving the hybrid vehicle 100 be transmitted. The second translation facility T2 is set up, the drive power of the second electrical machine E2 at least partially on the axle drive A. transferred to.

Furthermore, the arrangement in 1A also be operated in such a way that the mechanical (internal combustion engine) power of the internal combustion engine V at least partially via the clutch K on the axle drive A. and thus on the wheels R. is transmitted. This is done using the clutch K adjusted accordingly, so that the internal combustion engine V with the axle drive A. is coupled. Thus, in the 1A the hybrid vehicle 100 by means of the second electrical machine E2 or by means of a combination of the second electrical machine E2 and the internal combustion engine V are driven.

In one embodiment, the arrangement can consist of 1A no clutch K exhibit. Such an arrangement without a clutch K is called a serial hybrid arrangement. In this embodiment, the hybrid vehicle is driven only by the second electric machine 2.

1B shows an example of a power-split hybrid arrangement, which is referred to, among other things, as an eCVT hybrid arrangement. With an eCVT hybrid arrangement, there is a continuously variable transmission of the internal combustion engine power to the wheels R. possible. The structure of the eCVT hybrid arrangement is similar to the serial-parallel arrangement from FIG 1A . In contrast to the arrangement 1A the eCVT hybrid arrangement has a planetary gear P. instead of the clutch K on. The internal combustion engine V is via the planetary gear G with the first and the second electrical machine E1 , E2 connected. The internal combustion engine power is at least partially transferred to the planetary gear P. submitted. In some embodiments, the internal combustion engine power can be transmitted to a planet carrier of a planetary gear set of the planetary gear P. be delivered, the first electric machine E1 with the sun gear of the planetary gear P. be connected and the second electrical machine E2 hang on the ring gear of the planetary gear. This coupling of the internal combustion engine V , the first electric machine E1 and the second electric machine E2 is only an example and further coupling options are possible. By setting a variable counter-torque with the first electrical machine E1 can be the speed of the internal combustion engine V can be set variably. As a result, the performance of the internal combustion engine V branched and partly directly mechanically transmitted to the axle drive and partly electrically via the first electrical machine E1 and the second electric machine E2 .

In the 1C is another configuration of the powertrain 1 shown, which is a parallel hybrid arrangement with a mechanical continuously variable transmission CVT having. The internal combustion engine V can through the clutch K with the continuously variable transmission CVT coupled or from the continuously variable transmission CVT be decoupled. The continuously variable transmission CVT is set up to vary the internal combustion engine power on the axle drive A. and thus on the wheels R. transferred to. Furthermore, the drive train 1 just an electric machine E. that can be used as a drive motor. The electric machine E. can through the electrical storage IT Obtain electrical power in order to convert it into mechanical drive power by means of the optional second transmission device T2 and the final drive A. on the wheels R. can be transferred. The parallel hybrid arrangement makes it possible to drive the hybrid vehicle purely using a combustion engine, purely electrically or a combination of both.

Further configurations for the drive train 1 are in the 2A-C described. These configurations allow a purely internal combustion engine or a purely electric vehicle drive or a vehicle drive from a combination of both. The parallel hybrid arrangements shown differ in the position and the point of engagement of their electrical machines E1 , E2 .

2A shows the powertrain 1 which is similar to the previous configurations. The axle drive A. is connected to a front or rear axle of the hybrid vehicle. In contrast to the previous configurations, the powertrain has 1 out 2A a multi-step transmission DC on that with the internal combustion engine V is connected, and the first translation device T1 is located between the multi-step transmission DC and the final drive. The multi-step transmission DC is set up to apply an internal combustion engine output in predetermined ratios, ie in predetermined stages, to the axle drive A. and thus on the wheels R. transferred to. The multi-step transmission DC can be a manual or automatic gearbox. In one embodiment, the multi-step transmission DC be a dual clutch transmission.

The first electric machine E1 is used here as a belt starter generator and is connected to the crankshaft of the internal combustion engine via a belt V connected. Other embodiments of the first electrical machine as well E1 as a starter generator are possible. The second electric machine E2 is in front of the final drive A. arranged. Due to the arrangement of the first and second electrical machines E1 , E2 the hybrid arrangement shown is also referred to as a P0-P3 parallel hybrid.

In another embodiment (not shown), the second electrical machine E2 at the gear output of the multi-step gear DC be arranged.

2 B Fig. 10 shows a configuration of the powertrain 1 that led to the arrangement 2A is similar. For a description of the elements, therefore, reference is made upwards with the same reference symbols. The powertrain 1 out 2 B differs from that from 2A in that the powertrain 1 a first axle drive A1 has, which is arranged on a front axle of the vehicle, and a second axle drive A. which is arranged on a rear axle of the vehicle, and the internal combustion engine V via the multi-step transmission DC and the first translation device T1 with the first axle drive A1 is connected and the second electrical machine E2 with the second axle drive A2 . The internal combustion engine can thus V the wheels on the front axle RF drive and the second electric machine E2 the wheels on the rear axle RB . Due to the arrangement of the first and second electrical machines E1 , E2 the configuration shown is also referred to as a P0-P4 parallel hybrid.

2C Fig. 10 shows a configuration of the powertrain 1 that related to the configuration 2 B is similar. For a description of the elements, therefore, reference is made upwards with the same reference symbols. The powertrain off 2C differs from that from 2 B being that the first electric machine E1 is no longer provided as a belt starter generator, but between the internal combustion engine V and the multi-step transmission DC is arranged. Furthermore, the arrangement has 2C additionally the clutch K on with the electric machine E1 (and the multi-step transmission DC ) with the internal combustion engine V coupled or from the internal combustion engine V can be decoupled. The first electric machine E1 can be connected to the multi-step transmission either permanently or via a further clutch (not shown). Due to the arrangement of the first and second electrical machines E1 , E2 the hybrid arrangement shown is also referred to as a P2-P4 parallel hybrid.

3 Fig. 13 is a block diagram schematically showing the configuration of a hybrid vehicle 100 according to an embodiment of the present invention.

The hybrid vehicle 100 includes several components that use a data bus 30th communicate with each other, namely at least one control unit 10 and a battery system 20th .

A control unit (ECU) 10 is an electronic control unit that controls a number of internal combustion engine actuators V and the first and second electrical machines E1 , E2 controls. The control unit is also set up to receive relevant sensor signals from the multi-step transmission DC , from the continuously variable transmission CVT or from the planetary gear P. evaluate and convert these into control commands for the corresponding gear actuators. The control unit 10 is set up for this, depending on the configuration of the drive train 1 the multi-step transmission DC , the continuously variable transmission CVT or the planetary gear P. to control. The control unit is also 10 set up to open (decouple) and close (couple) the clutch K to control.

The battery system 20th can use the electrical storage IT , for example a battery, and power electronics. The electrical storage IT can be charged by connecting to an external power source. As an alternative or in addition, part of the torque generated by the internal combustion engine can be used by the first and / or second electrical machine E1 , E2 which work as a generator and can convert the torque into electrical energy, which is then stored in the electrical storage device IT can be (temporarily) saved. The power electronics control the high-voltage energy flow between the electrical storage IT and the electrical machines E1 , E2 and converts the direct current stored in the charging unit ( DC ) in alternating current (AC) for the electrical machines E1 , E2 around.

The data bus 30th can be implemented according to communication technologies such as CAN (controller area network), LIN (local interconnect network), FlexRay, LAN / Ethernet or MOST. Can also be in the vehicle 100 a combination of several different bus types can be used.

In 4A is an (operating) map of the internal combustion engine V shown by way of example and schematically. The speed n of the internal combustion engine is on the horizontal axis V (Engine speed) and that of the internal combustion engine on the vertical axis V generated torque M. Also are lines P ₁ , P ₂ , P ₃ to see the respective operating points of the internal combustion engine V with constant power, so-called power hyperbolas, where the power of P ₁ to P ₂ to P ₃ gets bigger. There is also a full load curve M _Max shown, the maximum achievable torque curve of the internal combustion engine V under full load, and an exemplary operating range SB for a special operating mode. About the hybrid vehicle 100 To operate in the special operating mode, the internal combustion engine V in the operating area SB operated. In the present example, the special operating mode is a catalyst heating mode.

Furthermore, there is an optimized operating range in the map T shown as an example in the form of a line (or trajectory) within the special operating mode SB is located. In other embodiments (not shown), the optimized operating range T also a single operating point or an area within the special operating mode SB being. The optimized operating area T is indicated by a large number of optimized speed-torque pairs (operating points). Accordingly, there is the optimized operating range T also an internal combustion engine performance P _VKM on that the internal combustion engine V when operating in the optimized operating range T can provide. In the example shown is the optimized trajectory T through the speed and torque limits (see dashed line SB ) the special operating mode SB limited. In other exemplary embodiments, a minimum speed and / or torque limitation of the optimized operating range T also be greater than the minimum speed and / or torque limit of the special operating mode SB . A maximum speed and / or torque limitation of the optimized operating range can accordingly be achieved T also be smaller than the maximum speed and / or torque limit of the special operating mode SB .

The optimized operating area T can be determined empirically. The optimized operating area T is determined with regard to an optimization criterion. In some embodiments, the optimized operating range may T also be determined on the basis of several optimization criteria. In the present example, the optimization criterion is the ratio of exhaust gas enthalpy to raw emissions for catalytic converter heating as a special operating mode SB . As long as the internal combustion engine V within the optimized operating range T or along the optimized trajectory T is operated, the hybrid vehicle can be operated in the catalytic converter heating mode and at the same time optimized for fuel consumption and emissions. Depending on the optimization method and criteria, the optimized area T have a different shape

In 4A has the optimized trajectory T an absolute optimum at the operating point I ₀ , at which the optimization criterion is best met. Furthermore are lines I ₁ , I ₂ , I ₃ , I ₄ shown, each of which corresponds to operating points of the same quality (with regard to optimization), the quality of the operating points from the inside to the outside (i.e. from the line I ₁ after line I ₄ ) decreases, ie the operating points are less optimized. Thus, for example, the operating points are on the line I ₁ better than the operating points on the line I ₂ . The lines I ₁ , I ₂ , I ₃ , I ₄ are also known as iso lines.

A maximum drive power is still in the map P _des of the drive train shown as a dashed line. The maximum drive power Pmax indicates which (positive) total drive power the hybrid vehicle can produce during the operating point of the internal combustion engine V along the optimized trajectory T can be moved or operated. The maximum drive power Pmax is made up of an internal combustion engine power P _VKM and an electrical power reserve P _{EM, max} .

mit
M = Drehmoment der Verbrennungskraftmaschine
N = Drehzahl der VerbrennungskraftmaschineThe internal combustion engine performance P _VKM is indicated by the optimized trajectory T . In particular, the internal combustion engine performance P _VKM calculate using the following formula: $${\mathrm{P.}}_{VK\mathrm{M.}}=2\ast \pi \ast \mathrm{M.}\ast n$$

With
M = torque of the internal combustion engine
N = speed of the internal combustion engine

The electrical power reserve P _{EM, max} is made by the electric machine E2 that can be used to drive the hybrid vehicle and the electrical storage IT made available. So can the electric machine E2 those in the electrical storage IT Convert stored energy into kinetic energy and use it to drive the hybrid vehicle. The electrical power reserve is therefore used P _{EM, max} as electrical power reserve of the drive train 1 . The electrical power reserve P _{EM, max} can therefore in addition to the internal combustion engine performance P _VKM can be accessed. The line for the maximum drive power Pmax is therefore obtained by shifting the line (parallel) T in the direction of the vertical axis by the contribution of the electrical power reserve P _{EM, max} .

Furthermore, is an exemplary current drive power P _act shown. The current drive power P _act indicates how much drive power by shifting the operating point of the internal combustion engine V along the optimized trajectory T while maintaining a (from the electrical power reserve P _{EM, max} retrieved) electrical drive power P _EM by the second electric machine E2 can be provided. As the requested electrical drive power P _EM is smaller than the electrical power reserve P _{EM, max} , there is still a retrievable reserve power P _{EM, res} from the electrical power reserve P _{EM, max} before. The reserve power P _{EM, res} can be calculated as follows: $${\mathrm{P.}}_{\mathrm{E.}\mathrm{M.},res}={\mathrm{P.}}_{\mathrm{E.}\mathrm{M.},max}-{\mathrm{P.}}_{\mathrm{E.}\mathrm{M.}}$$

In 4B the map is off 4A shown, with the iso-lines for the sake of clarity I ₁ , I ₂ , I ₃ , I ₄ have been omitted. In contrast to 4a is in 4B a moment band P _{VKM, res} shown that at each speed along the optimized trajectory T indicates a minimum and maximum torque. The moment band P _{VKM, res} provides a combustion engine power reserve for the drive train 1 which can be accessed at short notice. The internal combustion engine power reserve P _{VKM, res} can be used to make short-term changes in the drive power requirement P _des to operate without changing the speed of the internal combustion engine V (i.e. a shift in the operating point of the internal combustion engine V along the optimized trajectory T ) or changing the electrical drive power P _EM to have to perform. In other words, in order to serve a short-term change in the drive power requirement, one of the internal combustion engine V generated torque within the torque band P _{VKM, res} (up or down). This can lead to unfavorable conditions during unsteady operation of the internal combustion engine V and on (from changes in speed of the internal combustion engine V resulting) acoustically noticeable behavior of the internal combustion engine V to be avoided towards the driver.

Furthermore, in 4B additionally a minimum speed n _{T, min} and a maximum speed n _{T, max} on the optimized trajectory T specified. The operating point of the internal combustion engine V can then between the minimum speed n _{T, min} , n _{T, max} along the optimized trajectory T be moved. The minimum and the maximum speed n _{T, min} , n _{T, max} along the optimized trajectory T also correspond to a minimum and a maximum power limit P _{T, min} and P _{T, max} , which the internal combustion engine V during operation along the optimized trajectory T adheres to. Thus, analogous to the torque band mentioned above can also be used P _{VKM, res} a speed band through the minimum and maximum speed n _{T, min} , n _{T, max} in the speed direction over the optimized trajectory T be provided. In some embodiments, the above torque band P _{VKM, res} and the speed band can be provided. In these exemplary embodiments, a minimum and a maximum power limit can also be provided. A minimum power limit then corresponds to that point which is caused by the minimum speed _{limit n T, min} and the lower limit of the torque band P _{VKM, res} is shown. Correspondingly, the maximum power limit is at the point that is caused by the maximum speed _{limit n T, max} and the upper limit of the torque band P _{VKM, res} is shown. In other words, the minimum power limit corresponds to a point at the bottom left in a range defined by the minimum and maximum speed limits n _{T, min} , n _{T, max} and the torque band P _{VKM, res} is limited, and the maximum power limit corresponds to a point at the top right in this area.

This allows the internal combustion engine V operated in such a way that they have no lower or higher output P _VKM the internal combustion engine V provides that to exit the special operating mode SB can lead. Thus, it can be ensured that the hybrid vehicle 100 reliable in the special operating mode SB can be operated. This can also be used to ensure that the special operating mode SB does not become unnecessarily inefficient or unnecessarily extended. This is the case, for example, when the special operating mode is used for the minimum required duration during operation with minimum power SB all from the internal combustion engine V generated energy also completely from the electrical storage IT could be included.

5 shows a method for operating the hybrid vehicle during the special operating mode SB .

The drive power requirement is in S1 P _des for driving the hybrid vehicle 1 recorded. As mentioned above, the drive power requirement P _des For example, can be derived from the position of an accelerator pedal of the hybrid vehicle. There are also other options for recording the drive line requirement P _des are possible.

In S2, the internal combustion engine V in that for the special operating mode SB optimized operating range T operated. As in the in 4A example shown can be the optimized operating range T be an optimized operating line. The optimized operating area T is already known in advance and can, for example, be called up from a database by the vehicle control unit.
The drive power requirement is in S3 P _des by means of the drive train 1 implemented, the internal combustion engine V within the optimized operating range T is operated. This is the operating point of the internal combustion engine V depending on the drive power requirement P _des selected. In some embodiments, the powertrain is 1 set so that the internal combustion engine V can be operated as close as possible to the optimal operating point I ₀ . Thus, the drive power requirement P _des through the combustion engine performance P _VKM , through the electric drive power P _EM or a combination of both can be met.

As a rule, an attempt is made to meet the drive power requirement P _des through the combustion engine performance P _VKM by shifting the operating point of the internal combustion engine V along the optimized trajectory T to meet. However, it can happen that the drive power requirement P _des is greater or less than the internal combustion engine power P _VKM by shifting the operating point along the optimized trajectory T is adjustable. This performance gap ΔP can be determined as follows: $$\Delta \mathrm{P.}={\mathrm{P.}}_{des}-{\mathrm{P.}}_{VK\mathrm{M.}}$$

is ΔP greater than 0, the performance gap or lack of performance ΔP through the electrical drive power P _EM to be served. is ΔP less than 0, the performance gap or excess performance ΔP also through a corresponding translation of the internal combustion engine performance P _VKM as drive power to the wheels R. to be met. As an alternative or in addition, the first and / or second electrical machine can E1 , E2 operated as a generator to generate the excess of the internal combustion engine power P _VKM to convert it into electrical power. Thus, by operating the first and / or second electrical machine E1 , E2 as a generator, the electrical power reserve P _{EM, max} be built up by means of the excess power ΔP the electrical storage IT is loaded. In some embodiments where a torque band P _{VKM, res} around the optimized trajectory T is provided, the performance gap can ΔP can also be served by the power reserve made available by the torque band. is ΔP equals 0, the drive power requirement P _des by shifting the operating point of the internal combustion engine V along the optimized trajectory T and thus only through the internal combustion engine performance P _VKM to be met. It can thus be achieved that the internal combustion engine V along the optimized trajectory T is operated and at the same time the drive train meets the drive power requirement P _des Fulfills.

Becomes the operating point of the internal combustion engine V taking into account the minimum and maximum speed n _{T, min} , n _{T, max} mentioned above, the power gap is shifted ΔP with the help of the electrical power reserve P _{EM, max} served. This can ensure that the hybrid vehicle 100 or the internal combustion engine V safe in the special operating mode SB can be operated. The special operating mode SB is exited when a corresponding control signal to exit the special operating mode SB is present. This control signal can be generated if, for example, a driver performs a “kick-down”. In other examples, the control signal can be used to exit the special operating mode SB are generated when a state of charge of the electrical storage IT reaches a minimum or maximum state of charge. Basically, the minimum and maximum state of charge depend on the built-in electrical storage device. An example can be for certain electrical storage systems IT the state of charge limits are between 15% and 95%, for example.

In some embodiments, the internal combustion engine V depending on an average performance requirement P _{des, avg} operate. In some embodiments, the internal combustion engine V at an operating point along the optimized trajectory T operated to the mean power requirement P _{des, avg} to meet. A difference ΔP _{des, avg} between the (actual) drive power requirement P _des and the mean performance requirement P _{des, avg} can be expressed by the following formula: $$\Delta {\mathrm{P.}}_{des,avG}={\mathrm{P.}}_{des}-{\mathrm{P.}}_{des,avG}$$

The difference ΔP _{des, avg} between the (actual) drive power requirement P _des and the mean performance requirement P _{des, avg} can address the performance gap in the same way as above ΔP described by the drive train 1 operated / closed. The internal combustion engine can thus V along the optimized trajectory T operated to the mean drive power requirement P _{des, avg} to meet, for example. Power _{peaks (ΔP des, avg} is greater than 0) through the electrical power reserve P _{EM, max} can be covered.

In further embodiments, the shift of the operating point of the internal combustion engine along the optimized trajectory T also depending on the electrical and / or internal combustion engine power reserve P _{VKM, res} respectively. For example, if there is still a lot of electrical power reserve P _{EM, max} is present, the internal combustion engine V be operated closer to the optimal operating point I ₀ for a comparatively long time, since the power gap ΔP comparatively long due to the electrical power reserve P _{EM, max} can be operated. Correspondingly, if there is only little electrical power reserve P _{EM, max} is present, the internal combustion engine V be operated closer to the optimal operating point I ₀ for a comparatively short time, since the power gap ΔP comparatively short due to the electrical power reserve P _{EM, max} can be operated. In some embodiments, “a lot of electrical power reserve” can mean that a state of charge of the electrical storage device IT is greater than a predetermined limit load value. The limit load value can be between 95% and 15%. This enables a current performance of the powertrain 1 that depends on an (operating) temperature and / or on the state of charge of the electrical storage device IT and / or from an (operating) temperature of the first and / or second electrical machine E1 , E2 is dependent on the selection of the operating point of the internal combustion engine V must be taken into account.

Furthermore, for example, a short-term (power) change due to the internal combustion engine power reserve P _{VKM, res} are used to avoid unfavorable operating conditions during transient operation of the internal combustion engine V to avoid. The lower the internal combustion engine power reserve P _{VKM, res} is, the shorter its useful life, so that the operating point of the internal combustion engine V moved earlier. For example, the internal combustion engine power reserve P _{VKM, res} used when there is a distance / distance (power difference) from the desired power and the optimized trajectory T is below a predetermined distance value. Furthermore, the internal combustion engine power reserve P _{VKM, res} used to further increase the load on the internal combustion engine V to avoid which would otherwise lead to exiting the special operating mode SB would lead. The internal combustion engine power reserve can also P _{VKM, res} can be used to approximate the maximum converted emission mass flow for exhaust gas aftertreatment.

List of reference symbols

1

Powertrain

10

Control unit

20th

Battery system

30th

Data bus

100

Hybrid vehicle

A.

Axle drive

A1

axle drive on the front axle

A2

rear axle drive

CVT

Continuously variable transmission

DC

Multi-step transmission

E.

Electric machine

E1

first electric machine

E2

second electric machine

IT

electrical storage

I1-4

Iso lines

K

coupling

Mmax

Maximum torque curve

P.

Planetary gear

P1,2,3

Power hyperbolas

Pact

current drive power

Pdes

Drive power requirement

Pdes, avg

medium drive power requirement

Pmax

maximum drive power

ΔP

Performance gap

ΔPdes

Difference between drive power requirement and average drive power requirement

PEM

electrical drive power

PEM, max

electrical power reserve

PEM, res

electrical reserve power

PVKM

internal combustion engine performance

PVKM, res

internal combustion engine power reserve

R.

wheels

RB

Rear wheels

RF

Front wheels

SB

Special operating mode

T

optimized operating range / optimized line or trajectory

T1

first translation facility

T2

second translation device

V

Internal combustion engine

S1-S3

Procedural steps

QUOTES INCLUDED IN THE DESCRIPTION

This list of the documents listed by the applicant was generated automatically and is included solely 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

• US 6359404 B1 [0002]
• JP 2016037252 A [0003]
• JP 4967898 B2 [0004]

Claims (10)

A method for operating a hybrid vehicle (100) in a special operating mode (SB), the hybrid vehicle (100) having a drive train (1) which has an internal combustion engine (V), an electric machine (E1, E2) and an output, and the drive train _{(1) is set up to variably translate a power (P VKM} ) output by the internal combustion engine (V) to the output, the method comprising: detecting a drive _{power requirement (P des} ) for driving the hybrid vehicle (100) according to a driver's request; - Operating the internal combustion engine (100) in an operating range (T) optimized for the special operating mode (SB); and - Implementation of the drive power requirement (P _des ) by means of the drive train (100), the internal combustion engine (V) being operated within the optimized operating range (T). Procedure according to Claim 1 , the implementation of the drive _{power requirement (P des} ) by means of the drive train (1) further comprising at least one of the following: - translation of the power (P _VKM ) delivered by the internal combustion engine (V) to implement the drive line _{requirement (P des} ); and - operating the electrical machine (E1, E2) in a motor or generator mode to achieve the drive power requirement (P _des ). Procedure according to Claim 1 or 2 , wherein the optimized operating range (T) _{includes an optimal operating point (I 0} ) at a certain power of the internal combustion engine (V) and ancillary optimized operating points for further powers of the internal combustion engine (V). Method according to one of the preceding claims, wherein the optimized operating range (T) lies within a minimum power limit and a maximum power limit for the special operating mode (SB). Method according to one of the preceding claims, wherein the optimized operating range (T) lies within a minimum speed and a maximum speed for the special operating mode (SB). Method according to one of the preceding claims, wherein operating the internal combustion engine (V) within the optimized operating range (T) further comprises: - shifting an operating point of the internal combustion engine (V) within the optimized operating range (T) as a function of a power reserve of the drive train, wherein the Power reserve an electrical power reserve (P _{EM, max} ), which is made available by the electrical machine (E1, E2) and an electrical storage device (ES), and / or an internal combustion engine power _{reserve (P VKM, res} ), which is provided by a torque band is made available to the optimized operating range (T). Method according to one of the preceding claims, wherein the internal combustion engine (V) is operated as a function of an average drive power _{requirement (P des, avg} ). Method according to one of the preceding claims, wherein the special operating mode (SB) comprises a catalytic converter heating mode of the hybrid vehicle. Control device (10), which is set up, a method according to one of the preceding Claims 1 until 8th to execute. Hybrid vehicle (100) with a control unit (10) Claim 9 , wherein the hybrid vehicle (100) is set up and designed, a method according to the Claims 1 until 8th to execute.

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