CN106014655A - Method for controlling auxiliary compressorof drive device and control device - Google Patents

Abstract

The invention relates to a method for controlling an auxiliary compressor of a driving device comprising an internal combustion engine, a compression assembly and an auxiliary compressor, wherein the compression assembly is designed to generate a basic boost pressure and the auxiliary compressor is designed to Generates auxiliary boost pressure. The method includes: obtaining a rated torque, obtaining a variable representing a basic torque according to the rated torque, wherein the internal combustion engine generates the basic torque in response to a basic boost pressure, determining whether the basic torque is less than the rated torque according to the variable representing the basic torque, and when the basic torque is less than the rated torque , the variable characterizing the assist torque is obtained from the rated torque and the variable characterizing the base torque, wherein the internal combustion engine generates the assist torque in response to the assist boost pressure, and when the base torque is less than the rated torque, from the variable characterizing the assist torque in such a manner The auxiliary compressor is controlled such that the internal combustion engine provides total engine torque boosted by assist torque.

Description

Method and control device for controlling an auxiliary compressor of a driving device

technical field

The invention relates to a method and a control device for controlling an auxiliary compressor of a vehicle drive comprising an internal combustion engine, one or more compression assemblies provided in addition to the auxiliary compressor , and an auxiliary compressor, wherein the compression assembly is designed to generate a primary boost pressure for the internal combustion engine, and wherein the auxiliary compressor is designed to generate an auxiliary boost pressure for the internal combustion engine.

Background technique

Internal combustion engines are typically configured to provide torque to drive, for example, a vehicle. The torque can also be adjusted via the boost pressure of the air supplied by the internal combustion engine. In order to regulate the charge pressure, for example, throttle valves, exhaust gas turbochargers, waste gas recuperation valves and bypass valves can be provided in the intake tract of the compression unit of the internal combustion engine, which interact in such a way that they are adjusted to produce the desired torque boost pressure. However, an undesired delay occurs between the engagement of the compression assembly and the adjustment of the boost pressure, which leads to functional impairments, especially when the load changes, for example when the vehicle accelerates.

This lag is sometimes attributed to the delayed action of the exhaust gas turbocharger. In order to improve the response of the exhaust gas turbocharger, DE 10 2004 042 272 A1 proposes to derive the setpoint rotational speed of the compressor of the exhaustgas turbocharger from the deviation between the setpoint boost pressure and the actual boost pressure and to use the control element to control the speed of the compressor.

Furthermore, it is known, for example, from DE 103 02 453 A1 to provide an electrically assisted supercharger in the intake tract of an internal combustion engine and a bypass with a bypass valve in the exhaust tract. The boost pressure can then be adjusted through the cooperation of the exhaust gas turbocharger and the electro-assisted supercharger, wherein the bypass valve is actuated as a function of the rotational speed of the electro-assisted supercharger.

Contents of the invention

Even though methods and control devices for controlling an auxiliary compressor of a vehicle drive are basically known in the prior art, the technical problem underlying the invention is to provide an improved vehicle drive A method for an auxiliary compressor and a corresponding control device for controlling the auxiliary compressor.

This technical problem is solved by a method according to the invention for controlling an auxiliary compressor of a drive and a control device according to the invention for controlling an auxiliary compressor of a vehicle drive.

According to a first aspect, the invention relates to a method for controlling an auxiliary compressor of a drive of a vehicle having an internal combustion engine, one or more compression assemblies provided in addition to said auxiliary compressor, and The auxiliary compressor, wherein the compression assembly is designed to generate a primary boost pressure for an internal combustion engine, and wherein the auxiliary compressor is designed to generate an auxiliary boost pressure for an internal combustion engine, the method comprising:

obtain the rated torque for the drive;

obtaining a variable characterizing the base torque from the rated torque, wherein the internal combustion engine produces the base torque in response to the base boost pressure;

determining whether the base torque is less than the rated torque according to the variable used to characterize the base torque;

When the base torque is less than the rated torque, obtaining the variable characterizing the assist torque from the rated torque and from the variable characterizing the base torque, wherein the internal combustion engine generates the assist torque in response to the auxiliary boost pressure provided by the auxiliary compressor; and

When the base torque is less than the rated torque, the auxiliary compressor is controlled according to the variable characterizing the auxiliary torque in such a way that the internal combustion engine provides a total engine torque boosted by the auxiliary torque.

According to a second aspect, the invention relates to a control device for controlling an auxiliary compressor of a drive of a vehicle having an internal combustion engine, one or more compression assemblies provided in addition to said auxiliary compressor, and the auxiliary compressor, wherein the compression assembly is designed to generate a primary boost pressure for the internal combustion engine, and wherein the auxiliary compressor is designed to generate an auxiliary boost pressure for the internal combustion engine, wherein the control The device is designed to carry out the method for controlling an auxiliary compressor of a vehicle drive according to the first aspect.

A method according to the invention for controlling an auxiliary compressor of a drive of a vehicle having an internal combustion engine, one or more compression assemblies provided in addition to the auxiliary compressor, and the auxiliary compressor, wherein the compression assembly is designed to generate a primary boost pressure for the internal combustion engine, and wherein the auxiliary compressor is designed to generate an auxiliary boost pressure for the internal combustion engine, the method comprises: obtaining a Rated torque, according to the rated torque to obtain a variable used to characterize the basic torque, wherein the internal combustion engine generates a basic torque in response to the basic supercharging pressure, according to the variable used to characterize the basic torque to determine whether the basic torque is less than the rated torque, when the basic torque is less than At rated torque, the variable used to characterize the auxiliary torque is obtained from the rated torque and from the variable used to characterize the basic torque, where the internal combustion engine generates the auxiliary torque in response to the auxiliary boost pressure provided by the auxiliary compressor, and when the basic torque is less than the rated When the torque is increased, the auxiliary compressor is controlled in such a way that the internal combustion engine provides a total internal combustion engine torque which is boosted by the auxiliary torque.

The method according to the invention enables a targeted reaction to the driver's wishes contained within the setpoint torque by generating a suitable assist torque. As a result, the exhaust gas quantity and consumption of the drive can be optimized and driver comfort and driving pleasure can be increased. Since the auxiliary torque can only be provided when the base torque is less than the rated torque, or the auxiliary compressor can only be operated when the base torque is less than the rated torque, the auxiliary compressor can simultaneously keep the energy requirement low.

The auxiliary compressor is, for example, an electrical auxiliary compressor. For example, a rotary-piston supercharger or a screw supercharger driven by an electric motor or a radial compressor driven by an electric motor can be used as an electrical auxiliary compressor. The electric auxiliary compressor is characterized by rapid controllability and it allows a rapid acquisition of auxiliary boost pressure generating auxiliary torque. As a result, the required setpoint torque can be set quickly, wherein the energy consumption is adjusted in a suitable manner in order to protect the energy storage device from excessive loads. Alternatively, a pneumatic or otherwise driven compressor can also be used as an auxiliary compressor.

The compression package of a gasoline engine may include an exhaust turbocharger, a throttle valve and/or a bypass with a bypass valve. The compression unit of the diesel engine can include an exhaust gas turbocharger with variable turbine geometry and/or include a throttle valve. The exhaust gas turbocharger can have a turbine arranged in the exhaust tract of the internal combustion engine, and a compressor arranged in the intake tract of the internal combustion engine. For exhaust gas turbochargers with variable turbine geometry, the turbine preferably has adjustable guide vanes. The throttle valve is preferably arranged in the intake tract of the internal combustion engine in the air supply direction, preferably upstream of the turbine of the exhaust gas turbocharger. The bypass is designed, for example, as a channel which connects an exhaust tract region upstream of the turbine of the exhaust gas turbocharger in the exhaust gas discharge direction with an exhaust tract region downstream of the turbine.

The auxiliary compressor can be arranged in the intake tract of the internal combustion engine, for example in the intake tract, through which the internal combustion engine is supplied with intake air, to generate a boost pressure for the internal combustion engine. For example, the auxiliary compressor can be arranged upstream or downstream of the compressor of the exhaust gas turbocharger and/or downstream of the throttle valve in the intake tract of the internal combustion engine. The auxiliary compressor generates a boost pressure (auxiliary boost pressure) for the internal combustion engine which is proportional to the acquired assist torque.

The drive unit can have a crankshaft coupled to the internal combustion engine. The crankshaft preferably connects the drive via the transmission to the wheels of the vehicle in order to drive the vehicle. In particular, the auxiliary compressor is not connected to the crankshaft of the internal combustion engine, but is driven separately. As a result, the auxiliary compressor can be controlled independently of the operation of the internal combustion engine and can optionally be selectively engaged in the operation of the internal combustion engine.

Obtaining the rated torque may include receiving an adjustment signal indicative of accelerator pedal position and calculating the rated torque from the adjusted signal. The control signal can be received, for example, by a sensor which detects the position of the accelerator pedal.

The variable used to characterize the basic torque may be the real-time basic torque of the internal combustion engine, the real-time basic boost pressure in the combustion chamber of the internal combustion engine, or other parameters proportional to the real-time basic torque. The variable used to characterize the base torque can be obtained from one or more operating parameters of the internal combustion engine And/or state parameters are based on the performance of the electrical energy storage device (battery) and/or optionally from the performance of the drive unit of one or more further drive units.

To determine whether the base torque is less than the rated torque, the base torque can be subtracted from the rated torque. When the difference is positive, the base torque is less than the rated torque. Otherwise the base torque is greater than or equal to the rated torque.

The variable used to characterize the assist torque may be the real-time assist torque of the internal combustion engine, the real-time assist supercharging pressure in the combustion chamber of the internal combustion engine, or other variables proportional to the real-time assist supercharging pressure. The variable characterizing the auxiliary torque derived from the nominal torque can additionally be derived from the performance of the energy storage device (battery), from the performance of the auxiliary compressor, from the real speed of the internal combustion engine and/or from the performance of the internal combustion engine and/or optionally from one or more The performance of the power unit of an additional drive unit is realized. For example, the real-time adjusted driving speed level of the drive, the state of charge of the electrical energy storage, the aging of the electrical energy storage, the temperature of the electrical energy storage and/or the previous operating time and/or operating mode of the auxiliary compressor can be taken into account. Assist torque may additionally be related to auxiliary compressor readiness.

When controlling the auxiliary compressor, the auxiliary compressor can be adjusted in such a way that it provides an auxiliary boost pressure which causes the internal combustion engine to generate the acquired auxiliary torque.

The method for controlling the auxiliary compressor may include obtaining a maximum auxiliary compressor-boost boost pressure that can be provided by the auxiliary compressor and obtaining a maximum auxiliary compressor-boost boost pressure produced by the internal combustion engine at the maximum auxiliary compressor-boost boost pressure. Boost torque. The maximum auxiliary compressor-boost boost pressure is preferably defined by the real-time air mass flow through the intake tract. The acquisition of the maximum auxiliary compressor-boost boost pressure and the maximum auxiliary compressor-boost torque is preferably done in real-time because it is related to vehicle conditions such as engine speed, maximum auxiliary compressor-boost boost pressure and maximum auxiliary compressor-boost torque. related to changes in torque.

A maximum auxiliary compressor-boost torque may be provided in addition to a maximum base torque during a boost operation. The lifting operation is a medium-term acceleration operation, which can be requested by pushing the accelerator pedal of the drive all the way and lasts from a few seconds to a few minutes.

According to the described method for controlling the auxiliary compressor, the current available for the auxiliary compressor and/or the actual rotational speed of the internal combustion engine can additionally be taken into account when determining the maximum auxiliary compressor boost torque. Alternatively or additionally, when obtaining the maximum auxiliary compressor-boost torque, it is possible to take into account: state parameters of the driving device, such as a real-time adjusted road speed level; and/or state parameters of the electric energy storage device, such as the state of charge of the electric energy storage device , the aging of the electrical energy storage device and/or the temperature of the electrical energy storage device; and/or a state parameter of the auxiliary compressor, such as the boost duration during which the auxiliary compressor has produced said maximum auxiliary compressor-boost increase so far Pressure. Auxiliary compressor-boost torque may additionally be related to auxiliary compressor readiness.

For example, on the basis of the set driving speed level and the real speed of the internal combustion engine, a desired torque can be determined which is limited by a limit torque based on the current available to the auxiliary compressor and the internal combustion engine speed. The limited desired torque can then be converted to the auxiliary compressor maximum boost torque by means of a factor (Faktor) in the range 0 to 1 based on the defined real-time state of the electrical energy storage device and/or the real-time state of the auxiliary compressor One or more parameters to determine. For determining the desired torque, the factor and/or the engine characteristic curve of the limit torque can be taken into account.

The method for controlling the auxiliary compressor may additionally comprise ascertaining a maximum base torque of the internal combustion engine; determining an overall torque limit of the drive taking into account the maximum auxiliary torque and the maximum base torque; and comparing the rated torque with the overall torque limit Compare. The overall torque limit of the drive can be the maximum torque available for the entire drive, for example the sum of the maximum available torques of all drive units via the drive, such as the internal combustion engine, the auxiliary compressor and optionally the electric motor. If it is determined that the rated torque is greater than the overall torque limit when comparing the rated torque with the overall torque limit, the torque is limited to the overall torque limit. In other cases, the rated torque remains unchanged.

The maximum auxiliary compressor-boost torque here helps the drive to provide a boosted total torque. As a result, the efficiency of the drive can be effectively improved, which means, for example, that the vehicle can be accelerated better and faster.

In embodiments where the drive unit includes an internal combustion engine and an auxiliary compressor, but does not include an electric motor as an auxiliary power unit, the total torque limit may be the sum of the maximum auxiliary compressor-boost torque and the maximum base torque or may be the maximum internal combustion engine gross torque .

In certain exemplary embodiments, the drive can be a hybrid drive and have an electric machine in addition to the internal combustion engine and the auxiliary compressor. The electric machine is preferably connected to the crankshaft and provides electric motor torque for driving the vehicle. In this case, the method according to the invention additionally includes determining a maximum motor torque of the electric machine of the drive, wherein the maximum motor torque is taken into account when determining the overall torque limit value. For a hybrid drive, the total torque limit value can then be the sum of the maximum auxiliary compressor boost torque, the maximum base torque and the maximum electric motor torque or the sum of the maximum internal combustion engine total torque and the maximum electric motor total torque.

According to the method for controlling the auxiliary compressor, when it is known that the rated torque is greater than the total torque limit value in the process of comparing the rated torque with the total torque limit value, the maximum auxiliary compressor may be obtained in the process of obtaining the assist torque- Boost torque acts as assist torque. If, for example, even the residual drive unit of the drive unit is operated at maximum torque, the drive unit essentially provides a torque corresponding to the overall torque limit value.

With the aid of the maximum auxiliary compressor boosting torque, an increased overall torque of the internal combustion engine can be provided, so that a higher desired torque can be achieved, which is indicative of the driver's wishes. This is desirable, for example, when accelerating the vehicle, when the driver requires the highest possible torque, since this achieves driver comfort and a sporty driving.

According to the method for controlling the auxiliary compressor, when it is known that the rated torque is less than or equal to the total torque limit value and greater than the maximum base torque in the process of comparing the rated torque with the total torque limit value, it may be possible in the process of obtaining the assist torque The assist torque less than or equal to the maximum assist compressor-boost torque is obtained as the assist torque.

Depending on the method used to control the auxiliary compressor, a setpoint gradient of the boost pressure in the combustion chamber can be taken into account. As a result, targeted adjustments can be made as to how quickly the torque provided in real time should reach the setpoint torque. By means of a targeted adjustment of the torque available in real time, it is possible, for example, to limit exhaust emissions and/or to satisfy the driver's wishes for a short time.

The method for controlling an auxiliary compressor may alternatively or additionally comprise: obtaining a nominal boost pressure gradient; obtaining an auxiliary compressor-transient boost pressure providable by the auxiliary compressor based on the nominal boost pressure gradient; and obtaining at The Auxiliary Compressor-Transient Boost Pressure is a variable characterizing the auxiliary compressor-transient torque produced by the internal combustion engine. The boost pressure-setpoint gradient can be determined, for example, according to the driver's wishes. For this purpose, for example, a movement of the accelerator pedal, in particular a speed of movement of the accelerator pedal, can be detected and a charge pressure-setpoint gradient can be determined as a function of the movement of the accelerator pedal, in particular the speed of movement of the accelerator pedal.

Auxiliary compressor-transient torque may be provided in addition to base torque during transient compensation operation. Transient compensation operations are brief compensation operations lasting at most a few seconds. The variables used to characterize the auxiliary compressor-transient torque can be the auxiliary compressor-transient torque itself, the auxiliary compressor-transient boost pressure, the rotational speed of the auxiliary compressor to be regulated, the auxiliary Compressor transient current, or other variable proportional to auxiliary compressor-transient torque.

According to the method for controlling the auxiliary compressor, when the total engine torque is less than or equal to the maximum base torque of the engine, the auxiliary compressor-transient torque may be equal to the difference between the total engine torque and the base torque. In this case, the assist torque may correspond to the assist compressor-transient torque. The auxiliary compressor-transient torque may be equal to the difference between the maximum base torque and the base torque when the total engine torque is greater than the maximum base torque of the internal combustion engine. In this case, the assist torque is equal to or greater than the assist compressor-transient torque.

The variable characterizing the auxiliary compressor-transient torque may be less than or equal to the variable characterizing the maximum auxiliary compressor-transient torque. The variable characterizing the maximum auxiliary compressor-transient torque may be determined based on the current available to the auxiliary compressor, the real speed of the internal combustion engine, and/or the state parameters mentioned above. For example, the duration of the transient during which the auxiliary compressor has currently produced auxiliary boost pressure may be included in deriving the variable characterizing the maximum auxiliary compressor-transient torque.

For example, the detected variable characterizing the auxiliary compressor-transient torque may be the rotational speed of the auxiliary compressor to be adjusted. The variable characterizing the maximum auxiliary compressor-transient torque may then be the maximum auxiliary compressor-transient current, which is converted into a maximum rotational speed in order to limit the rotational speed of the auxiliary compressor to be regulated. As a result, such auxiliary compressor transient torques can also be tolerated during brief compensating operations, the energy consumption of which is optimized by means of the maximum auxiliary compressor transient torque.

For example, the current can be determined based on the adjusted driving speed level and the real-time rotational speed of the internal combustion engine and based on one or more parameters defining the real-time state of the electrical energy storage device and/or the real-time state of the auxiliary compressor. factor, with which the determined current is then converted into the maximum auxiliary compressor transient current. Maximum Auxiliary Compressor - Transient Current can additionally be used to limit the rated speed of the auxiliary compressor based on the current being used by and by the auxiliary compressor, thereby maximizing the maximum impact on the maximum compensation by the auxiliary compressor torque.

Therefore, the assist torque can be selected such that it best matches the base torque and the rated torque. In this way, for example, base torques which cause high exhaust emissions can be avoided without reducing the overall torque of the internal combustion engine.

When the drive device includes an electric motor, the method for controlling the auxiliary compressor may further comprise determining an electric motor torque to be provided by the electric motor, wherein the auxiliary torque is determined based on the electric motor torque. The assist torque can then best match the base torque, electric motor torque and rated torque.

The invention also relates to a control device for controlling an auxiliary compressor of a vehicle drive having an internal combustion engine, one or more compression assemblies provided in addition to the auxiliary compressor, and the auxiliary compressor, In this case, the compression assembly is designed to generate a basic boost pressure of the internal combustion engine, and the auxiliary compressor is designed to generate an auxiliary boost pressure of the internal combustion engine. The control device is designed to carry out the method for controlling an auxiliary compressor of a drive device as explained above.

The control means preferably comprises a processor, such as a microprocessor, and a data memory. A program is preferably stored in the data memory, the program including instructions for the processor to control the electric auxiliary compressor corresponding to the method described.

The control device can comprise a plurality of signal inputs and signal outputs. For example, control signals describing the position of the accelerator pedal, the rotational speed of the internal combustion engine, information about the electrical energy storage device and/or further parameters can be received via the signal input. The electrical auxiliary compressor, the internal combustion engine, the compression unit and optionally the electric motor can be controlled via the signal output.

The control unit can be partly or completely integrated into the engine control unit.

The invention furthermore relates to a vehicle, in particular a motor vehicle, having a drive device and a control device as described above. The drive device has an internal combustion engine, one or more compression assemblies provided in addition to the auxiliary compressor, and the auxiliary compressor, wherein the compression assembly is designed to generate a basic boost pressure of the internal combustion engine, and the The auxiliary compressor is designed to generate auxiliary boost pressure for the internal combustion engine. The internal combustion engine may be a gasoline engine or a diesel engine (or called a diesel internal combustion engine).

The vehicle can include an accelerator pedal with a sensor, from which a control signal can be supplied to the control device. In addition, the vehicle can comprise sensors for detecting the rotational speed of the internal combustion engine and/or for providing information about the electrical energy storage device and/or other parameters, which sensors are likewise connected to the control device via data lines.

Description of drawings

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

FIG. 1 schematically shows a first embodiment of a drive train with a control device according to the invention;

Figure 2 schematically shows an internal combustion engine with an intake duct section and an electrically-assisted compressor for the drive train;

Fig. 3 shows a flowchart of a method for controlling an electrically assisted compressor according to a first embodiment;

Fig. 4 shows a schematic diagram of the variation of the maximum assist torque with the speed of the internal combustion engine;

Fig. 5 shows a schematic diagram of the assist torque changing with time at an approximately steady speed;

FIG. 6 shows a flow chart of a method for determining an overall torque limit value in the case of controlling an electrically assisted compressor according to a first embodiment;

Figure 7 schematically shows a second embodiment of a drive train with a control device according to the invention;

Fig. 8 shows a flowchart of a method for controlling an electrically assisted compressor according to a second embodiment;

Fig. 9 shows a schematic diagram of the variation of the maximum assist torque and the maximum electric motor torque with the speed of the internal combustion engine;

Fig. 10 shows a schematic diagram of the variation of motor torque with time at approximately steady speed;

FIG. 11 shows a flowchart of a method for determining an overall torque limit value when controlling an electrically assisted compressor according to a second exemplary embodiment.

detailed description

A first exemplary embodiment of a drive train 1 is shown in FIG. 1 . The drive train 1 comprises a drive device 2 which is connected via a crankshaft 10 and a transmission 11 to a drive shaft 12 in order to move the wheels of the vehicle connected to the drive shaft 12 .

As shown in FIG. 2 , the drive device 2 has an internal combustion engine 20 and an electric auxiliary compressor 21 . The internal combustion engine 20 is connected to the intake duct 22 of the intake tract section of the internal combustion engine 20 and to the exhaust duct 23 . In order to regulate the charge pressure in the intake duct 22 , the intake tract of the internal combustion engine 20 includes an exhaust gas turbocharger 24 with a turbine 240 and a compressor 241 which is connected via a shaft to the turbine 240 . The turbine 240 is arranged in the exhaust passage 23 and is driven by exhaust gas discharged from the internal combustion engine 20 . The compressor 241 is arranged in the intake passage 22 and is driven by the turbine 240 to compress the air in the intake passage 22 .

The electric auxiliary compressor 21 is arranged downstream of the compressor 241 of the exhaust gas turbocharger 24 in the air supply direction 25 in the intake duct 22 and is designed to increase the boost pressure in the intake duct 22 . This leads to an increase in the torque of the drive 2 compared to a drive without an electric auxiliary compressor, as will be explained in more detail below with reference to FIGS. 3 and 6 with regard to the method for controlling the electric auxiliary compressor.

As shown in FIG. 1 , vehicle 1 additionally has an engine control unit 3 and an energy storage unit 4 . The engine control unit 3 is connected via a data line 130 to the drive unit 2 to obtain the rotational speed of the internal combustion engine 20 , via a data line 131 to the energy storage device 4 to obtain information about its state, and via a data line 132 to the accelerator pedal 14 A sensor (not shown) is connected to receive an adjustment signal including the driver's intention. The engine control device 3 includes a processor and a storage device. The processor is designed to carry out, by means of a program stored in a storage device, a method for controlling an electrically assisted compressor as explained further below with reference to FIGS. 3 and 6 . The engine control unit 3 is connected to the drive unit 2 via a data line 133 in order to control the electric auxiliary compressor 21 in such a way that the internal combustion engine 20 supplies the total engine torque M _VZ increased by the auxiliary torque M _Z and supplies the drive unit 2 with Further control commands, for example the supply of the setpoint position of the throttle valve, information for injection and other commands.

An energy storage device 4 in the form of a battery is connected to the drive device 2 in order to supply it with electrical energy.

FIG. 3 shows a method 5 for controlling the electric auxiliary compressor 21 . In step 50 , the setpoint torque for the drive is ascertained, including the driver's desire. For this purpose, a control signal is received from a sensor on the accelerator pedal and the target torque is determined using the control signal.

In step 51 , a base torque M _V is determined from the nominal torque, wherein the internal combustion engine generates the base torque M _V in response to the base boost pressure provided by the exhaust gas turbocharger, the throttle valve, the waste gas recovery valve and the bypass valve. The base torque M _V is a torque smaller than or equal to the maximum base torque M _Vmax shown in FIG. 4 . FIG. 5 shows an exemplary time profile of the base torque M _V achieved at an approximately steady speed.

In step 52 it is determined whether the base torque M _V is less than the nominal torque.

In step 53, when the base torque M _V is less than the rated torque, the assist torque M _Z is obtained according to the rated torque and the base torque M _V , wherein the internal combustion engine generates the assist torque M _Z in response to the auxiliary boost pressure provided by the electric auxiliary compressor. The auxiliary torque M _Z is selected in such a way that the overall torque M _VZ of the internal combustion engine is adjusted quickly, but still with low emissions, to a value corresponding to the setpoint torque. During acceleration, the total torque limit value M _max should be reached, for example, quickly.

In step 54, when the basic torque M _V is smaller than the rated torque, the auxiliary compressor is controlled according to the auxiliary torque M _Z in such a way that the internal combustion engine provides the total internal combustion engine torque M _{VZ boosted} by the auxiliary torque M _Z , in FIG. 5 The time course of the overall torque M _VZ of the internal combustion engine is shown at an approximately steady speed.

When the setpoint torque is ascertained in step 50 , the setpoint torque can additionally be determined taking into account the total torque limit value M _max . FIG. 6 shows a method 6 for determining the overall torque limit value M _max .

In step 60 , the maximum basic boost pressure that can be provided by the exhaust gas turbocharger, the throttle valve, the waste gas recovery valve and the bypass valve is determined. In step 61 , the maximum basic torque M _Vmax produced by the internal combustion engine based on this maximum basic boost pressure is ascertained.

In step 62 , the maximum boost boost pressure of the auxiliary compressor that can be provided by the auxiliary compressor at the maximum base boost pressure is determined. The state of the battery, the mass flow in the intake tract of the internal combustion engine and the rotational speed of the internal combustion engine are taken into account here.

In step 63 , the maximum auxiliary compressor boost torque M _Boostmax generated via the internal combustion engine based on the maximum auxiliary compressor boost boost pressure is determined. The maximum auxiliary compressor boost torque M _Boostmax denotes the maximum achievable auxiliary compressor boost torque of the electric auxiliary compressor, which is provided by the drive with the support of the electric auxiliary compressor during rapid acceleration.

In step 64 , an overall torque limit value M _max of the drive is determined taking into account the maximum auxiliary compressor boost torque M _Boostmax and the maximum base torque M _Vmax . The total torque limit M _max is the maximum torque that can be generated by the drive under prevailing control conditions. In the present exemplary embodiment, the total torque limit value M _max corresponds to the internal combustion engine maximum torque M _VZmax .

FIG. 4 shows a schematic diagram of the maximum basic torque M _Vmax and the overall torque limit value M _max as a function of the speed of the internal combustion engine. The maximum base torque M _Vmax increases linearly in the low speed range A and remains substantially constant in the middle speed range B. The maximum base torque M _Vmax then drops again in the high speed range C. The overall torque limit value M _max increases linearly in the low speed range A, wherein this increase is however smaller than the increase of the maximum base torque M _Vmax . The overall torque limit value M _max drops slightly in the middle speed range B, after which it drops more rapidly in the high speed range C similarly to the maximum base torque M _Vmax .

The maximum auxiliary compressor boost torque M _Boostmax is obtained from the difference between the total torque limit value M _max and the maximum basic torque M _Vmax , which is shown in FIG. 4 as between the total torque limit value M _max and the maximum basic torque M _Vmax The distance is shown. The maximum auxiliary compressor boost torque M _{Boostmax drops} sharply in the low speed range A and slightly decreases in the middle speed range B as the speed increases. In the high speed range C, the maximum boost torque M _Boostmax remains essentially unchanged. Since the maximum auxiliary compressor boost torque M _Boostmax is highest at low speeds, the electric auxiliary compressor works particularly effectively just during acceleration at low speeds.

FIG. 5 shows the temporal profile of the base torque M _V of the internal combustion engine and the temporal profile of the overall torque M _ZV of the internal combustion engine at an approximately steady speed. The base torque M _V increases substantially linearly until it reaches a maximum base torque M _Vmax and thereafter remains constant. The overall internal combustion engine torque M _VZ increases faster than the basic internal combustion engine torque M _V until it reaches the overall torque limit value M _max or the maximum overall internal combustion engine torque and then remains constant. The increase of the base torque M _V and the total internal combustion engine torque M _VZ can be varied depending on the driver's wishes or depending on the movement of the accelerator pedal, in order to optimize the acceleration process, in particular to perform it quickly and with low emissions.

The auxiliary torque M _Z influenced by the electric auxiliary compressor is defined as the difference between the overall internal combustion engine torque M _VZ and the base torque M _V . As a function of time, the auxiliary torque M _Z first increases and then decreases again as soon as the _sum of the base torque M _V and the auxiliary torque M _Z or the overall torque M _VZ of the internal combustion engine equals the overall torque limit value M _max .

Assist torque M _Z may include auxiliary compressor-instant torque M _Inst and/or auxiliary compressor-boost torque M _Boost . If it is known from the setpoint torque that the driver wishes to increase the overall torque (internal combustion engine overall torque M _VZ ), the electric auxiliary compressor first causes a transient compensation and then transitions to a boosting process. Before the total internal combustion engine torque M _VZ reaches a value equal to the maximum basic torque M _Vmax , an auxiliary torque M _Z equal to the auxiliary compressor transient torque M _Inst is generated by the electric auxiliary compressor. Auxiliary compressor-transient torque M _{Inst must} not exceed the maximum auxiliary compressor-transient torque related to engine speed and battery state. The overall internal combustion engine torque M _VZ is increased more rapidly by the auxiliary compressor transient torque M _Inst .

The auxiliary compressor-instantaneous torque M _Inst is determined by ascertaining a nominal boost pressure gradient, on the basis of which the auxiliary compressor-instantaneous boost pressure that can be provided by the auxiliary compressor is determined and thereby Auxiliary Compressor - Instantaneous Torque M _Inst . When the total engine torque M _VZ is less than or equal to the maximum basic torque M _Vmax of the internal combustion engine, the auxiliary compressor-transient torque M _Inst is equal to the difference between the total internal combustion engine torque M _VZ and the basic torque M _V , and when the total internal combustion engine torque M _VZ is greater than the maximum internal combustion engine torque At the base torque M _Vmax , the auxiliary compressor-transient torque M _Inst is equal to the difference between the maximum base torque M _Vmax and the base torque M _V . Auxiliary compressor-transient torque M _Inst is less than or equal to a maximum auxiliary compressor-transient torque related to current available for the auxiliary compressor, engine speed and/or drive, battery and The status parameters of the auxiliary compressor are related.

If the overall torque M _VZ is greater than the maximum base torque M _Vmax , the base torque is less than the maximum base torque M _Vmax , and the overall torque M _VZ of the internal combustion engine of the drive should be increased further, the drive transitions to lifting operation. In this case, the electrical auxiliary compressor generates an auxiliary torque M _Z consisting of an auxiliary compressor transient torque M _Inst and an auxiliary compressor boost torque M _Boost .

If the base torque M _V reaches a value equal to the maximum base torque M _Vmax and the total engine torque M _VZ should be increased further to accelerate the vehicle, the assist torque M _Z is equal to the auxiliary compressor-boost torque M _Boost . The auxiliary compressor boost torque M _Boost is increased up to a value equal to the maximum auxiliary torque M _Boostmax when the maximum base torque M _Vmax is achieved.

A second embodiment of a drive train 1 ′ is shown in FIG. 7 . In comparison with the drive train 1 in FIG. 1 , the drive 2 ′ of the drive train 1 ′ has an electric machine 26 (E-Maschine) as an auxiliary drive. The internal combustion engine 20 and the electric auxiliary compressor 21 are designed as described with reference to FIG. 2 . Electric machine 26 is connected to internal combustion engine 20 and to transmission 11 and is designed to generate an electric motor torque M _E . The electric machine 26 is connected to the engine control unit 3 via a data line 134 . The engine control unit 3 is designed to control the electric machine 26 in such a way that it provides a suitable electric motor torque M _E for use.

Figure 8 shows a method 5' for controlling the electric auxiliary compressor 21. Steps 50 and 51 correspond to steps 50 and 51 in FIG. 3 .

In step 55 , the motor torque M _E is determined as a function of the setpoint torque base torque. The motor torque M _E is a torque smaller than the maximum motor torque M _Emax shown in FIG. 9 . An exemplary time profile of the acquired electric motor torque M _E at an approximately steady speed is shown in FIG. 10 .

In step 52 ′ it is determined whether the sum M _E + M _V of the base torque M _V and the motor torque M _E is less than the nominal torque.

In step 53', when the sum of the basic torque M _V and the motor torque M _E M _E + M _V is less than the rated torque, the auxiliary torque M _Z is obtained according to the rated torque, the obtained basic torque M _V and the motor torque M _E , where the engine generates assist torque M _Z in response to the assist boost pressure provided by the assist compressor. The auxiliary torque M _Z is selected in such a way that the overall torque of the drive is quickly adjusted to a value equal to the target torque in a low-emission manner. During acceleration, for example, the total torque limit value M _max should be reached quickly. Said overall torque is equal to the sum of the overall torque M _VZ of the internal combustion engine and the torque M _E of the electric motor.

In step 54', when the sum of the base torque M _V and the electric motor torque M _E M _E + M _V is less than the rated torque, the auxiliary compressor is controlled such that the internal combustion engine provides the total internal combustion engine torque boosted by the auxiliary torque M _Z M _VZ , and its time-varying curve is shown in FIG. 9 .

In step 50 , the overall torque limit value M _max can also be taken into account in determining the setpoint torque in addition to the set signal of the sensor on the accelerator pedal.

FIG. 11 shows a method 6 ′ for determining the total torque limit value M _max taking into account the electric motor torque M _E . Steps 60 , 61 , 62 and 63 correspond to steps 60 , 61 , 62 and 63 in FIG. 6 . In step 65, the maximum internal combustion engine torque M _VZmax is determined on the basis of the maximum base torque M _Vmax and the maximum auxiliary compressor-boost torque M _Boostmax , and the maximum electric motor torque M _Emax that can be supplied by the electric machine with the maximum internal combustion engine torque M _VZmax is determined . In step 64 ′, an overall torque limit value M _max of the drive is determined taking into account the maximum auxiliary compressor boost torque M _Boostmax , the maximum base torque M _Vmax and the maximum electric motor torque M _Emax .

A schematic diagram of the curves of the maximum basic torque M _Vmax , the maximum overall internal combustion engine torque M _VZmax and the overall torque limit M _max as a function of the rotational speed of the internal combustion engine is shown in FIG. 9 . The course of the maximum basic torque M _Vmax and the maximum overall torque M _VZmax of the internal combustion engine is as explained with reference to FIG. 4 . The overall torque limit value M _max has a stable value in the low rotational speed range A. The total torque limit M _max drops slightly in the middle speed range B and sharply in the high speed range C.

The maximum electric motor torque M _Emax results from the difference between the overall torque limit value M _max and the maximum overall torque M _VZmax of the internal combustion engine, which is shown in FIG. 9 as the distance between the overall torque limit value M _max and the maximum overall torque M _VZmax of the internal combustion engine out. As the speed increases, the maximum total motor torque M _Emax drops sharply in the low speed range A and slightly in the middle speed range B. In the high speed range C, the maximum total motor torque M _Emax is basically stable. Since the maximum total motor torque M _Emax is substantially constant, the motor can be efficiently used at all speeds during acceleration.

FIG. 10 shows the time profile of the base torque M _V of the internal combustion engine and the time profile of the torque M _E +M _V corresponding to the sum of the electric motor torque M _E and the base torque M _V at an approximately constant speed. The base torque M _V increases substantially linearly until it reaches a maximum base torque M _Vmax and thereafter remains constant. Torque M _E +M _V increases analogously to internal combustion engine base torque M _V until it reaches a maximum torque M _Emax +M _Vmax and then remains constant.

The motor torque M _E caused by the electric machine is defined as the difference between the torque M _E +M _V and the base torque M _V . The motor torque M _E is substantially constant over time.

Like the assist torque M _Z also shown in Fig. 5, the motor torque M _E can also be supplemented in transient operation to quickly reach rated torque, and also in lifting operation to increase the overall torque of the drive train. torque.

list of reference signs

1. 1' drive system

10 crankshaft

11 transmission

12 drive shaft

130-134 data cable

14 accelerator pedal

2, 2' drive unit

20 internal combustion engine

21 Electric Auxiliary Compressor

22 air intake

23 exhaust duct

24 exhaust gas turbocharger

240 Turbo

241 compressor

25 Air supply direction

26 motor

3 Engine controls

4 Energy Storage Devices

5, 5' Method for controlling electrical auxiliary compressors

50 Get the nominal torque of the drive

51 Get base torque

52, 52' Determine whether the base torque and if necessary the motor torque is less than the rated torque

53, 53' for assist torque

54, 54' control auxiliary compressor

55 Get Motor Torque

6, 6' Method for determining the total torque limit

60 Determining the maximum base boost pressure

61 Get maximum base torque

62 Get the maximum Auxiliary Compressor-boost boost pressure that can be provided by the Auxiliary Compressor

63 Get Maximum Auxiliary Compressor-Boost Torque

64, 64' Determine the total torque limit

65 Determining the maximum torque of an internal combustion engine

A low speed range

B middle speed range

C high speed range

M torque

M _E motor torque

M _Emax maximum motor torque

M _V base torque

M _Vmax maximum base torque

M _VZ Internal Combustion Engine Gross Torque

M _VZmax internal combustion engine maximum total torque

M _max total torque limit

Auxiliary Torque for M _Z Electric Auxiliary Compressors

M _Boost auxiliary compressor boosts torque

M _Boostmax auxiliary compressor maximum boost torque

M _Inst Auxiliary Compressor Instantaneous Torque

n internal combustion engine speed

t time

Claims (10)

1. A method for controlling an auxiliary compressor (21) of a driving device (2, 2') of a vehicle, said driving device comprising an internal combustion engine (20), one or more A compression assembly (24), and an auxiliary compressor (21) are also provided, wherein the compression assembly (24) is designed to generate a basic boost pressure for the internal combustion engine (20), and wherein the auxiliary compressor ( 21) Designed to generate auxiliary boost pressure for an internal combustion engine (20), said method comprising: obtaining (50) a rated torque for the driving device (2); Deriving (51) a variable characterizing a base torque from said nominal torque, said base torque (M _V ) being produced by the internal combustion engine in response to said base boost pressure; determining (52) whether the base torque is less than the rated torque according to the variable characterizing the base torque; When the base torque (M _V ) is smaller than the rated torque, obtaining (53, 53') a variable characterizing the auxiliary torque (M _Z ) from the rated torque and the variable characterizing the base torque, wherein said internal combustion engine (20) generates said auxiliary torque (M _Z ) in response to auxiliary boost pressure provided by said auxiliary compressor (21); and When said base torque (M _V ) is smaller than said nominal torque, said auxiliary compressor (21 ) is controlled ( 54 , 54 ′) according to said variable characterizing the auxiliary torque (M _Z ) in such a way, The internal combustion engine (20) is made to provide the total internal combustion engine torque (M _VZ ) boosted by the assist torque (M _Z ). 2. The method of claim 1, comprising: obtaining (62) the maximum auxiliary compressor-boost boost pressure capable of being provided by the auxiliary compressor (21); and The maximum auxiliary compressor-boost torque (M _Boostmax ) produced by the internal combustion engine (20) at the maximum auxiliary compressor-boost boost pressure is obtained (63). 3. A method according to claim 2, wherein the current available for the auxiliary compressor ( ₂₁ ), the rotational speed of the internal combustion engine (20) and/or Or a state parameter of the drive device (2, 2') and/or a state parameter of the electrical energy storage device (4) and/or a state parameter of the auxiliary compressor (21). 4. A method according to claim 2 or 3, comprising: obtaining the maximum basic torque of the internal combustion engine described in (61); determining ( 64 , 64 ′) the total torque limit (M _max ) of the drive ( 2 , 2 ′) taking into account the maximum auxiliary torque (M _Boostmax ) and the maximum base torque (M _Vmax ); Compare the rated torque with the total torque limit (M _max ). 5. The method of claim 4, comprising: A maximum motor torque (M _Emax ) of _an electric machine (26) of the drive (2, 2') is determined (65), which is taken into account when determining the overall torque limit value (M _max ). 6. A method according to claim 4 or 5, wherein when the rated torque is greater than the total torque limit (M _max ), the maximum auxiliary compressor-boost torque (M _Boostmax ) is taken as the auxiliary torque (M _Z ), and Wherein when the rated torque is less than or equal to the total torque limit value (M _max ), an assist torque less than or equal to the maximum boost torque of the auxiliary compressor (M _Boostmax ) is obtained as the assist torque (M _Z ). 7. The method according to any one of claims 1 to 6, comprising: Obtain the boost pressure rated gradient; Deriving an auxiliary compressor-transient boost pressure capable of being provided by the auxiliary compressor (21) based on said boost pressure nominal gradient; and A variable characterizing auxiliary compressor-transient torque produced by an internal combustion engine (20) at said auxiliary compressor-transient boost pressure is obtained. 8. The method of claim 7, wherein the auxiliary compressor-transient torque is equal to the difference between the total engine torque and the base torque when the total engine torque is less than or equal to the maximum base torque of the engine, and wherein when the total engine torque is greater than At the maximum base torque of the internal combustion engine, the auxiliary compressor-transient torque is equal to the difference between the maximum base torque and the base torque. 9. A method according to claim 7 or 8, wherein the variable characterizing the auxiliary compressor-transient torque is less than or equal to the variable characterizing the maximum auxiliary compressor-transient torque, said maximum auxiliary compressor - the variable of the transient torque can be related to the current used by the auxiliary compressor (21), the speed of the internal combustion engine (20) and/or the state parameters of the drive means (2, 2') and/or the state of the electric energy storage means (4) parameters and/or state parameters of the auxiliary compressor (21). 10. A control device for controlling an auxiliary compressor (21) of a driving device (2, 2') of a vehicle having an internal combustion engine (20), one or more In addition, a compression assembly, and said auxiliary compressor (21), wherein said compression assembly is designed to generate a basic boost pressure for the internal combustion engine, and wherein said auxiliary compressor (21) is designed to Generating an auxiliary boost pressure for an internal combustion engine (20), wherein the control device is designed to perform an auxiliary for controlling a drive device (2, 2') of a vehicle according to one of claims 1 to 9 compressor method.