DE102011075145A1 - Method for operating a drive train of a hybrid vehicle - Google Patents

Abstract

Method for operating a drive train of a hybrid vehicle, which has a drive unit (1) comprising an electrical machine (3) and an internal combustion engine (2) and an electrical energy storage device (7), the electrical energy storage device being more discharged during motor operation of the electrical machine and in regenerative operation is more strongly charged, with an output torque depending on a selected operating mode in an electrical operating mode exclusively via the electrical machine (3) or in a hybrid operating mode both via the electrical machine and via the internal combustion engine (2) in compliance with the output (4) of a state of charge operating area of the electrical energy store (7), a hybrid preparatory operating mode with an extended state of charge operating area of the electrical energy store automatically being triggered by a driver actuating an operating element r Preparation of an electrical operating mode or hybrid operating mode that is related to the driver's actuation of the control element after a defined travel distance or duration of travel is activated, whereby in the preparation operating mode the electric machine and the internal combustion engine are operated in such a way that after the defined travel distance or duration of travel the charge state of the electrical energy store ( 7) corresponds to an extended limit of the extended state of charge operating range.

Description

The invention relates to a method for operating a drive train of a hybrid vehicle according to the preamble of claim 1. Furthermore, the invention relates to a control device for carrying out the method.

Hybrid vehicles, the drive unit comprising an electric machine and an internal combustion engine, are well known in practice. Thus, hybrid vehicles can be operated purely electrically in an electric operating mode, in which case only the electric machine of the hybrid vehicle at an output of the same provides an output torque. Furthermore, hybrid vehicles can be operated in a hybrid mode of operation, in which case both the electric machine and the internal combustion engine of the hybrid vehicle at the output provides an output torque. The electric machine of such a hybrid vehicle can be operated on the one hand by a motor and on the other hand by a generator, wherein in the motor operation of the electric machine the same one more discharges an electrical energy store of the hybrid vehicle and charges it more in regenerative operation.

From practice, it is also already known to predictively determine an operating mode for the hybrid vehicle on the basis of topographical data of a driving distance ahead of the hybrid vehicle. This topographical data of the route lying in front of the hybrid vehicle is provided by a navigation system or a GPS system in hybrid vehicles known from practice. Alternatively, it is also known for hybrid vehicles such. B. for city buses, which are operated on recurring routes to measure the routes in advance by departing the same and maintain appropriate route data in a memory. Both the provision of the topographical route data via a GPS system or navigation system and the pre-measurement by driving off the routes and storage of the route data requires a high device complexity and application costs.

There is therefore a need for a method for operating a drive train of a hybrid vehicle and at a control device for carrying out such a method, with which without the need for a GPS system or navigation system and without the need for pre-measurement of the route by departing the same a suitable operating mode for a hybrid vehicle with optimization of the efficiency of the hybrid vehicle can be selected.

On this basis, the present invention based on the object to provide a novel method for operating a drive train of a hybrid vehicle and a control device for carrying out the method.

This object is achieved by a method according to claim 1. According to the invention, a hybrid preparation operating mode with an extended permissible charge state operating range of the electrical energy store is automatically activated by a driver-side actuation of an operating element in preparation for a related to the driver-side actuation of the control element after a defined driving distance or driving subsequent electric mode or hybrid mode activated, wherein in the hybrid preparation operating mode, the electric Engine and the internal combustion engine are operated so automatically that after the defined route or travel time of the state of charge of the electric energy storage automatically corresponds to an extended limit of the extended allowable state of charge operating range.

The method according to the invention runs automatically after a driver-side release by actuation of a control element.

For performing the method no topographic route data is needed. The hybrid vehicle according to the invention thus comes without GPS system and navigation system. Furthermore, it is not necessary to pre-measure a route by departing the same and to save corresponding route data.

Rather, after the driver-side actuation, a hybrid preparation mode of operation is automatically activated and selected for the operation of the hybrid vehicle, with the hybrid preparation mode of operation providing an extended allowable state of charge operating range for the electrical energy storage over the previous hybrid mode or electric mode.

During the hybrid preparation mode of operation, the powertrain is automatically operated such that after the defined cruise distance or drive duration after activation of the hybrid preparation mode, the state of charge of the electrical energy store automatically corresponds to an extended, upper or extended lower limit of the extended, allowable state of charge operating range of the electrical energy store.

As a result, without knowing the topographical distance data, the hybrid vehicle adjusts or prepares for an electric operation mode or subsequent hybrid operation mode subsequent to the hybrid preparation operation mode.

According to an advantageous development, when the hybrid preparatory operating mode is activated, a charging state of the electrical energy store that forms is automatically monitored in such a way that if a defined travel distance or time interval is detected before the defined travel distance or travel time expires, the charge state of the electrical energy store is the upper limit value has not yet reached or will not reach the extended allowable state of charge operating range, a load point boost is automatically made to the internal combustion engine. This development of the invention is particularly suitable for adapting or preparing the hybrid vehicle to an electric operating mode for a zero emission travel path following the hybrid preparation operating mode or to a subsequent hybrid operating mode for uphill driving or for a subsequent hybrid operating mode with power takeoff activation.

According to a further advantageous development, when the hybrid preparatory operating mode is activated, a charging state of the electrical energy store that forms is automatically monitored such that when a defined travel distance or time interval is detected before the defined travel distance or travel time expires, the charge state of the electrical energy store is extended Lower limit of the extended allowable state of charge operating range has not yet reached or will not reach automatically a load point reduction is made for the internal combustion engine. This development of the invention is particularly suitable for adapting the hybrid vehicle to an electric operating mode or hybrid operating mode for a downhill following the hybrid preparation operating mode.

Preferably, the defined driving distance or driving time of the hybrid preparation operating mode is automatically determined when the operator controls the driving element, with a constant driving distance or driving time or a variable driving distance or driving time depending on an operating time or operating frequency of the operating element being used as the defined driving distance or driving time of the hybrid preparation operating mode. The above determination of the defined travel distance or travel time of the hybrid preparation operating mode, within which the electrical state of charge of the electrical energy store is to adopt the extended limit value of the extended state of charge operating range, is particularly simple and preferred.

The control device according to the invention has means for carrying out the method according to the invention.

Preferred embodiments of the invention will become apparent from the dependent claims and the description below. Embodiments of the invention will be described, without being limited thereto, with reference to the drawings. Showing:

1 an exemplary schematic of a hybrid vehicle;

2 a diagram for illustrating the method according to the invention for operating a drive train of a hybrid vehicle.

The present invention relates to a method for operating a drive train of a hybrid vehicle and to a control device for carrying out the method.

1 shows very schematically a drive train scheme of a hybrid vehicle with a drive unit 1 which is an internal combustion engine 2 and an electric machine 3 includes. Between the drive unit 1 and a downforce 4 The hybrid vehicle is a transmission 5 switched, which is preferably designed as an automatic or automated manual transmission. Between the internal combustion engine 2 and the electric machine 3 of the drive unit 1 is a clutch 6 connected. With the clutch open 6 is the internal combustion engine 2 from the downforce 4 decoupled, in which case with the clutch open 6 the internal combustion engine 2 set quiet and the drive train purely electrically in an electrical mode of operation starting from the electric machine 3 can be driven. For a hybrid mode of operation, the clutch is 6 closed, in which case the internal combustion engine 2 running in hybrid mode and through the closed clutch 6 to the output 4 is coupled. The electric machine 3 of the drive unit 1 is an electrical energy storage 7 assigned. The electrical energy storage 7 is in the motor operation of the electric machine 3 from the same more dischargeable and in generator operation of the electric machine 3 from the same more rechargeable. In this case, a permissible state of charge operating range of the electrical energy store 7 , which is defined by an upper limit and a lower limit, complied with.

The operation of the internal combustion engine 1 is the powertrain of the 1 from an engine control device 8th controlled or regulated. to Control of the operation of the transmission 5 The powertrain includes a transmission control device 9 , A hybrid control device 10 controls or regulates the operation of the electric machine 3 ,

For controlling or regulating the components 1 . 3 and 5 via the control devices 8th . 9 and 10 exchange the controls 8th . 9 and 10 with the components 2 . 3 and 5 in the sense of double arrows data, including the control device 8th . 9 and 10 exchange data with each other.

It should be noted at this point that the hybrid control device 10 also part of the transmission control device 9 or the engine control device 8th can be.

According to the invention, it is proposed that triggered by a driver-side actuation of a control element 11 the powertrain of the hybrid vehicle automatically a hybrid preparation operating mode for the operation of the drive train in preparation for a relative to the driver-side operation of the control element 11 is activated after a defined distance or travel duration subsequent electric operation mode or hybrid operation mode.

This hybrid preparation mode of operation is characterized by an extension of the allowable state of charge operating range of the electric energy storage. To extend the allowable state of charge operating range, an upper limit of the state of charge operation range is shifted upward or a lower limit of the state of charge operation range downward, respectively.

In the hybrid preparation mode of operation then become the electric machine 3 and the internal combustion engine 2 of the drive unit 1 operated so automatically that after the defined route or travel time of the hybrid preparation operation mode, the state of charge of the electrical energy storage 7 automatically an extended limit of the extended, allowable state of charge operating range of the electrical energy storage 7 that is, either the upper limit shifted above or the lower limit of the state of charge operating range shifted down.

The method according to the invention accordingly provides a drive train, in particular the state of charge of an electrical energy store 7 of the drive train, triggered by a driver-side actuation of the control element 11 fully automatic on a subsequent electric operation mode or hybrid operating mode, namely such that with completion of the hybrid preparation mode and thus with the beginning of the subsequent electric operation mode or hybrid mode of operation of the state of charge of the electrical energy storage 7 a limit value extended or shifted for the hybrid preparation operating mode of the extended, permissible charge state operating range of the electrical energy storage device 7 equivalent.

Hereinafter, the invention with reference to 2 in the event that the powertrain of a hybrid vehicle is to be automatically prepared for an electric operation mode for a zero emission travel ahead of the hybrid vehicle. This is done in 2 in which, over time t or over a distance s, the state of charge SOC of the electrical energy store 7 is plotted at a time t0 or at a distance s0 by driver-side actuation of the control element 11 automatically activates the hybrid preparation mode and this automatically an upper limit SOC-MAX of the permissible state of charge operating range of the electrical energy storage 7 raised to the extended, upper limit SOC-MAX-E. Subsequently to this driver-side actuation of the operating element 11 and the automatic activation of the hybrid preparation operating mode effected thereby is in particular controlled by the hybrid control device 10 for carrying out the method according to the invention, in the hybrid preparation operating mode, the internal combustion engine 2 as well as the electric machine 3 operated so automatically that, based on the driver-side operation of the operating element 11 at time t0 or at the distance s0 after a defined travel time .DELTA.t1 or after a defined travel distance .DELTA.s1, the state of charge SOC of the electrical energy storage 7 automatically to the extended, upper limit SOC-MAX-E of the extended, permissible charge state operating range of the electrical energy storage 7 equivalent.

Depending on the unknown topographical route profile during the route Δs1 or travel time Δt1 of the preparatory mode of operation, a chronological progression or travel-route-dependent course of the state of charge SOC is formed, namely from an initial value SOC-0 of the state of charge at the time t0 or the distance s0 in such a way that at the end of the preparatory operating mode with expiration of the travel time Δt1 or with travel of the distance Δs1, the raised, upper limit value SOC-MAX-E of the extended, permissible charge state operating range of the electrical energy store 7 is reached.

When activated, hybrid preparation operating mode, ie during the route Δs1 or the travel time .DELTA.t1, the developing state of charge SOC of the electrical energy storage 7 monitored automatically such that when it is detected that a defined distance Δs2 distance or a defined time interval .DELTA.t2 before expiration of the defined distance .DELTA.s1 or the defined travel time .DELTA.t1, the state of charge SOC of the electrical energy storage 7 has not yet reached or will not reach the extended upper limit of the extended allowable state of charge operating range, automatically increases the load point of the internal combustion engine 2 takes place, so that the state of charge SOC of the electrical energy storage 7 the limit value SOC-MAX-E which has been increased or raised at the end of the defined travel distance Δs1 or the defined travel time Δt1 has been reached with the assistance of the internal combustion engine.

With expiration of the travel time .DELTA.t1 or reaching the distance Δs1 after automatic activation of the hybrid preparation operating mode, the previously raised or extended, upper limit of the permissible state of charge operating range is again reduced during the subsequent change to the prepared electric operating mode for the zero emission travel distance and preferably based on this operating mode change who in 2 is carried out at the time t1 or to the driving position s1, for a defined distance or travel time lowered the lower limit of the permissible state of charge operating range to a purely electrical operation of the hybrid vehicle via the electric machine during the entire electric operating mode of the zero emission travel distance 3 under stronger discharge of the electrical energy storage 7 to ensure.

The defined travel distance .DELTA.s1 or travel time .DELTA.t1 of the hybrid preparation operating mode is the driver-side actuation of the control element 11 automatically by the process performing controller, in the embodiment shown by the hybrid control device 10 , certainly.

In this case, it can be provided that a constant travel distance or driving time is used and selected as defined travel distance Δs1 or travel time Δt1 of the hybrid preparation operating mode, which is selected for each actuation of the corresponding operating element 11 is constant.

Alternatively it can be provided as a defined distance Δs1 or travel time .DELTA.t1 of the hybrid preparation operating mode, a variable, by an actuation duration or actuation frequency of the operating element 11 dependent travel distance Δs1 or travel time Δt1 to use. Thus it can be provided that for each actuation of the operating element 11 an increment for the defined travel distance Δs1 or travel time Δt1 of the hybrid preparation operating mode in the hybrid control device 10 is deposited. So is the driver side, the control 11 actuated only once, then a relatively short distance .DELTA.s1 or travel time .DELTA.t1 for the hybrid preparation operating mode is then automatically determined and used, whereas, when the actuating element 11 is operated repeatedly, a correspondingly longer driving distance .DELTA.s1 or travel time .DELTA.t1 is determined and used the hybrid preparation operating mode.

For the hybrid preparation operating mode for preparing the subsequent electric operation mode for a zero emission travel distance, it may be provided, for example, that with a simple actuation of the operating element 11 is used as a trip Δs1 of the hybrid preparation operation mode a 200m travel that is used with double actuation of the control element a distance Δs1 of 400m, that with triple actuation a distance Δs1 of 600m is used and that with n-fold operation of the control element a travel distance Δs1 which is n × 200m is used.

The method according to the invention is not limited to the preparation of an electric operating mode for a zero emission travel route. Rather, with the method according to the invention or the control device according to the invention, a hybrid operating mode for uphill driving or a hybrid operating mode with a power take-off activation, which is also referred to as PTO activation, can be carried out.

Thus, it is possible in the preparation of a preparatory operating mode for an upcoming uphill drive using the method according to the invention or the control device according to the invention, after driver-side actuation of the operating element 11 automatically activate the hybrid preparation mode of operation in the automatically determined defined travel distance Δs1 or travel time Δt1 after actuation of the control element 11 and before starting the hybrid operation mode for the uphill driving the state of charge SOC of the electrical energy storage 7 Accordingly, namely, by automatically activating the hybrid preparation operation mode automatically raised, upper limit value SOC-MAX-E of the state of charge operating range for the electrical energy storage 7 , In this case, the state of charge of the electrical energy store is then automatically raised accordingly during the preparation mode of operation, so that for the subsequent uphill hill, in which less Rekuperationsenergie can be obtained, a sufficient State of charge of the electrical energy store 7 is present. For all other details, reference may be made to the above-described procedure for preparing a zero mission route electrical operation mode.

An analogous procedure is possible for a hybrid vehicle via the hybrid preparation operating mode, after the driver-side actuation of a control element 11 is automatically enabled to prepare for a subsequent hybrid drive in hybrid mode with PTO enabled or power take-off enabled. In such a power take-off may be, for example, a cooling loader of a truck or other power take-off.

Furthermore, with the method according to the invention, it is possible to prepare a hybrid vehicle via the hybrid preparation operating mode for a subsequent electric operating mode or hybrid operating mode for a downhill run. In this context, then after appropriate actuation of the control element 11 and thereby effected, automatic activation of the hybrid preparation operating mode, the allowable state of charge operating range extended so that a lower limit thereof is shifted downwards and thus extended. Furthermore, in this context then the electric machine 3 as well as the internal combustion engine 2 operated such that at the end of the defined route or travel time of the hybrid preparation operating mode of the state of charge of the electrical energy storage 7 takes this lower limit of the extended allowable state of charge operating range.

In this case, when the hybrid preparation operating mode is activated, the state of charge of the electrical energy storage device is formed 7 is preferably automatically monitored so that when it is determined that a defined path distance or time interval before expiration of a defined route or driving time of the hybrid preparation operating mode, the state of charge has not reached the extended, lower limit or will not reach automatically a load point reduction for the Internal combustion engine is made, so that the electrical energy storage 3 over the electric machine 3 is discharged more heavily, so that then the recuperation potential of lying in front of the hybrid vehicle downhill can be fully utilized in the subsequent transition to the electric mode or hybrid mode for the downhill.

If appropriate, then for the subsequent downhill run, the upper limit of the state of charge operating range can be raised in order to fully exploit the recuperation potential.

In all embodiments of the invention, it is possible for the driver to activate the hybrid preparatory operating mode, which is automatic upon driver-side actuation of the operating element 11 is activated via a display device 12 to visualize.

Furthermore, the driver can use this display device 12 an upcoming end of the hybrid preparatory mode of operation may be displayed so that the driver may adjust to an operating mode change from the preparatory mode of operation to the subsequent electric mode of operation or subsequent hybrid mode of operation.

After activation of a hybrid preparation operating mode by corresponding driver-side actuation of the operating element 11 may be further provided in the sense of the invention that by subsequent actuation of the control element 11 the preparatory operation mode is aborted and returned to a regular electric operation mode or hybrid operation mode with a charge state operation region restricted from the extended charge state operation region.

It may be provided, for each prepared electrical operating mode or hybrid operating mode, a separate control element 11 provided. Furthermore, provision can be made for a common operating element for operating modes to be prepared in the same direction in relation to the state of charge of the electrical energy store in the sense of greater charge or boosting of the electrical energy store 11 provided.

The control device according to the invention is preferably a hybrid control device. The same has means for carrying out the method according to the invention, in particular interfaces for direct or indirect, unidirectional or bidirectional data exchange with the operating element 11 and / or the electric machine 3 and / or the electrical energy storage 7 and / or the internal combustion engine 2 and / or the display device 12 and / or the clutch 6 , as well as software-side and / or hardware-side means for the evaluation and generation of corresponding, serving the implementation of the method data signals. An indirect data exchange takes place via interposition of another control device.

The extended limit values for the extended charge state operating range of the electrical energy store in the preparation operating mode and the defined travel distances or driving times Δs1, Δt1, Δs2, Δt2 of the preparation operating mode and optionally increments for the defined travel distances or driving times Δs1, Δt1 of the preparation operating mode are preferably in stored a memory of the control device according to the invention and freely applicable via an interface.

LIST OF REFERENCE NUMBERS

1

power unit

2

internal combustion engine

3

electric machine

4

output

5

transmission

6

clutch

7

electrical energy storage

8th

Motor controller

9

Transmission control device

10

Hybrid controller

11

operating element

12

display element

Claims (11)

Method for operating a drive train of a hybrid vehicle, which comprises an electric machine ( 3 ) and an internal combustion engine ( 2 ) comprehensive drive unit ( 1 ), one between the drive unit ( 1 ) and an output ( 4 ) switched gear ( 5 ) and an electrical energy store ( 7 ), wherein the electrical energy store ( 7 ) in the motorized operation of the electric machine ( 3 ) and in regenerative operation of the electric machine ( 3 ) is more charged, with the downforce ( 4 ) an output torque depending on a selected for the operation of the drive train operating mode in an electric operating mode exclusively via the electric machine ( 3 ) or in a hybrid mode of operation both via the electric machine ( 3 ) as well as via the internal combustion engine ( 2 ) in each case while maintaining an allowable state of charge operating range of the electrical energy store ( 7 ), characterized in that, triggered by a driver-side actuation of a control element, a hybrid preparation operating mode with an extended permissible charge state operating range of the electrical energy store ( 7 ) is activated in preparation for a related to the driver-side actuation of the control element after a defined route or travel duration subsequent electric operation mode or hybrid mode, wherein in the hybrid preparation operating mode, the electric machine ( 3 ) and the internal combustion engine ( 2 ) are operated automatically such that automatically corresponds to the extended state of the extended state of charge operating range after the defined route or journey time of the state of charge of the electrical energy storage device. Method according to Claim 1, characterized in that, when the hybrid preparatory operating mode is activated, such a charging state of the electrical energy store (FIG. 7 ) is automatically monitored, that when a defined path distance or time interval is detected before expiration of the defined route or travel time that the state of charge of the electrical energy storage ( 7 ) has not or will not reach an extended upper limit of the extended allowable state of charge operating range, automatically increases a load point for the internal combustion engine ( 2 ) is made. A method according to claim 2, characterized in that upon activation of the hybrid preparation operating mode, the upper limit of the permissible state of charge operating range for expanding the same is automatically increased, wherein the subsequent changeover to the now prepared Elektrobetriebsmodus or hybrid mode, the upper limit of the permissible state of charge operating range again reduced and with respect to this Operating mode change for a defined route or travel time is lowered, the lower limit of the permissible state of charge operating range. A method according to claim 2 or 3, characterized in that the hybrid preparation operating mode prepares a subsequent electric operation mode for a zero emission travel route or a hybrid operation mode for uphill driving or a hybrid operation mode with power take-off activation. Method according to one of Claims 1 to 4, characterized in that, when the hybrid preparation operating mode is activated, such a charging state of the electrical energy store (FIG. 7 ) is automatically monitored, that when a defined path distance or time interval is detected before expiration of the defined route or travel time that the state of charge of the electrical energy storage ( 7 ) has not reached or will not reach an extended lower limit of the extended allowable state of charge operating range, automatically a load point depression for the internal combustion engine ( 2 ) is made. A method according to claim 5, characterized in that the hybrid preparation operating mode prepares a subsequent electric operation mode or hybrid operation mode for downhill driving. Method according to one of claims 1 to 6, characterized in that automatically after expiration of the defined route or journey duration is changed from the hybrid preparation operation mode to the now prepared electric operation mode or hybrid operation mode. Method according to one of claims 1 to 7, characterized in that the defined travel distance or travel time of the hybrid preparation operating mode is automatically determined when the driver side actuation of the control element. Method according to one of the claim 8, characterized in that a constant travel distance or travel duration is used as the defined travel distance or travel time of the hybrid preparation operating mode. Method according to one of claim 8, characterized in that as a defined travel distance or travel time of the hybrid preparation operation mode, a variable, dependent on an operating time or frequency of operation of the operating element driving distance or travel time is used. Control device of a hybrid vehicle, in particular hybrid control device, characterized in that the same means for performing the method according to one of claims 1 to 10.

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