阅读说明：本技术 用于运行混合动力车辆的方法和控制设备 (Method and control device for operating a hybrid vehicle ) 是由 M·福格特 A·克鲁斯 S·阿佩尔 C·霍姆 于 2019-07-04 设计创作，主要内容包括：本发明涉及一种用于运行混合动力车辆(1)的方法,所述混合动力车辆包括电机(3)、电池(4)和内燃机(2),在用于给电池(4)充电的发电机运行中提高其负荷点以驱动电机(3),预设电池(4)的目标荷电状态；确定需要的目标充电功率；首先仅在被列为有利的内燃机(2)特性曲线范围(9)内提高内燃机(2)的负荷点；如果在预设的时间段内根据获取的电池(4)平均实际充电功率判定,仅通过在被列为有利的特性曲线范围(9)内的负荷点提高不会达到目标荷电状态,那么在离开被列为有利的内燃机(2)特性曲线范围(9)的情况下进一步提高内燃机(2)的负荷点。本发明还涉及一种用于混合动力车辆(1)的控制设备(6)和具有所述控制设备(6)的混合动力车辆(1)。(The invention relates to a method for operating a hybrid vehicle (1) comprising an electric machine (3), a battery (4) and an internal combustion engine (2), the load point of which is increased in the generator mode for charging the battery (4) in order to drive the electric machine (3), a target state of charge of the battery (4) being predetermined; determining a required target charging power; firstly, the load point of the internal combustion engine (2) is increased only in the range (9) of the characteristic curve of the internal combustion engine (2) that is classified as advantageous; if it is determined from the acquired average actual charging power of the battery (4) within a predetermined time period that the target state of charge is not reached only by increasing the load point within the characteristic curve range (9) that is classified as favorable, the load point of the internal combustion engine (2) is increased further if the characteristic curve range (9) of the internal combustion engine (2) that is classified as favorable is left. The invention also relates to a control device (6) for a hybrid vehicle (1) and a hybrid vehicle (1) having the control device (6).)

1. Method for operating a hybrid vehicle (1) comprising an electric machine (3), a battery (4) and an internal combustion engine (2), the load point of which is increased for driving the electric machine (3) in generator operation for charging the battery (4),

it is characterized in that the preparation method is characterized in that,

-presetting a target state of charge of the battery (4) at a future point in time, according to a plurality of parameters determining the electric power demand of the hybrid vehicle (1);

-determining a target charging power required to reach a preset target state of charge of the battery (4);

-initially increasing the load point of the internal combustion engine (2) as a function of the determined target charging power only in a range (9) of the characteristic curve of the internal combustion engine (2) which is listed as advantageous in terms of efficiency and/or noise emission;

-if it is decided from the obtained average actual charging power of the battery (4) within a preset time period: if the load point is increased only within the characteristic curve range (9) that is classified as favorable and the target state of charge is not reached, the load point of the internal combustion engine (2) is increased further away from the characteristic curve range (9) of the internal combustion engine (2) that is classified as favorable.

2. The method according to claim 1, characterized in that the target state of charge of the battery (4) is preset as a function of the current state of charge of the battery (4), the power demand of the auxiliary loads of the hybrid vehicle (1) and/or the speed of the hybrid vehicle (1).

3. The method according to claim 1 or 2, characterized in that the range of the characteristic curve (9) classified as favorable is expanded in the direction of a stronger noise emission of the internal combustion engine (2) the faster the hybrid vehicle (1) is driven.

4. Method according to one of the preceding claims, characterized in that threshold values for efficiency and/or for noise emission are preset, which specify a range (9) of the characteristic curve of the internal combustion engine (2) which is listed as favorable.

5. Method according to any of the preceding claims, characterized in that if it is decided from the average battery (4) actual charging power obtained within a preset time period: if the target state of charge is not reached by a previous increase in the load point, the load point of the internal combustion engine (2) is gradually increased further outside the range (9) of the characteristic curve of the internal combustion engine (2) that is classified as advantageous.

6. Method according to any of the preceding claims, characterized in that the torque limit of the electrical machine (3) is preset in respect of its generator operation, and that the load point increase is performed only in case the torque limit is not exceeded.

7. The method according to any one of the preceding claims, characterized in that prediction data are provided, which describe future changes in the state of charge of the battery (4) caused by regeneration, which are taken into account when the load point of the internal combustion engine (2) increases and/or when a target state of charge is preset.

8. The method according to any one of the preceding claims, characterized in that prediction data relating to an operating strategy of the hybrid vehicle (1) are provided, which prediction data describe when the hybrid vehicle (1) is driven in the future by means of the electric machine (3) and/or by means of the internal combustion engine (2), said prediction data relating to the operating strategy being taken into account when the load point of the internal combustion engine (2) increases and/or when a target state of charge is preset.

9. The method according to any one of the preceding claims, characterized in that road characteristics of the hybrid vehicle (1) to be traveled are taken into account when the load point of the internal combustion engine (2) is increased and/or when the target state of charge is preset.

10. The method according to any one of the preceding claims, characterized in that the driver characteristics of the driver of the hybrid vehicle (1) are taken into account when the load point of the internal combustion engine (2) is increased and/or when the target state of charge is preset.

11. A control device (6) for a hybrid vehicle (1) for implementing a method according to any one of the preceding claims.

12. A hybrid vehicle (1) having the control apparatus (6) according to claim 11.

Technical Field

The invention relates to a method for operating a hybrid vehicle of the type described in the preamble of claim 1. The invention also relates to a control device for operating a hybrid vehicle and a hybrid vehicle having such a control device.

Background

It is known that, in hybrid vehicles, an electric machine for driving the vehicle can also be operated during generator operation in order to charge the vehicle battery.

DE 102010022018 a1 describes a method for operating a vehicle having an internal combustion engine and a generator. When the internal combustion engine is running, the partial torque of the torque exerted by the internal combustion engine on the shaft is used to generate an electric current in the generator. In the first mode, the partial torque is determined in such a way that the efficiency is set to a maximum value. In the second mode, the partial torque is determined in such a way that the efficiency is set to a lower value. If it is desired in urban environments to charge the vehicle battery more quickly, the partial torque is determined in the second mode, since the vehicle should only be driven for a short time with the internal combustion engine and only be driven electrically after the battery has been charged.

DE 102013020759 a1 proposes a method for regulating a hybrid drive unit in a vehicle. The target charging power of the vehicle battery is reduced in such a way that the internal combustion engine is operated at an optimum operating point during the charging process of the battery.

DE 102008008238 a1 proposes a charging strategy for a hybrid drive. The charging strategy comprises different charging and discharging functions for the vehicle battery, which are adjusted by the load point shift of the internal combustion engine.

Disclosure of Invention

The object of the present invention is to provide a method and a control device for a hybrid vehicle, by means of which a particularly efficient supply of electrical energy for the hybrid vehicle can be achieved.

The object is achieved by a method and a control device for operating a hybrid vehicle having the features of the independent claims. Advantageous embodiments with suitable and non-trivial developments of the invention are given in the dependent claims.

In the method according to the invention for operating a hybrid vehicle, which comprises an electric machine, a battery and an internal combustion engine, the load point of the internal combustion engine is increased for driving the electric machine during the operation of the generator for charging the battery. The method according to the invention is characterized in that a target state of charge of the battery at a future point in time is preset on the basis of a plurality of parameters determining the electric power demand of the hybrid vehicle. Subsequently, a target charging power required to achieve the preset target state of charge of the battery is determined. The load point of the internal combustion engine is first increased as a function of the determined target charging power only in the range of the characteristic curve of the internal combustion engine which is rated as advantageous in terms of efficiency and/or noise emission. And if the judgment is made according to the acquired average actual charging power of the battery within a preset time period: if the load point is increased only in the range of the characteristic curve classified as favorable and the target state of charge cannot be achieved, the load point of the internal combustion engine is further increased when the range of the characteristic curve classified as favorable is left. In particular, the process according to the invention is carried out continuously. The future time point can also be moved further forward, for example, at certain intervals all the time again and the target charging power can be determined again for the new future time point accordingly. The increase in the load point or the multiple increases in the load point then likewise take place continuously as required.

According to the invention, it is therefore proposed that, if the actual charging power does not reach the preset target state of charge of the battery at a future point in time as a result of the load point increase of the internal combustion engine within the range of the characteristic curve classified as advantageous, an upgrade is initiated, according to which the load point increase of the internal combustion engine is disadvantageously shifted in terms of efficiency and/or noise emission of the internal combustion engine.

The electrical energy necessary for charging the vehicle electrical system and in particular the battery, if the electrical energy is not accumulated to a sufficient extent by regeneration, is made available by the load point shift or operating point shift of the internal combustion engine optimized according to the invention. The following movements of the load point are particularly advantageous here: in this movement, the load lines are close to each other and have a state without abnormality in terms of acoustics. If the hybrid vehicle is in motion, the additional load point shift is acoustically more favorable than in the motionless state of the hybrid vehicle. If the load point moves very much, this means very high loads for the motor and the battery as well as thermal and electrical losses, whereby this is also not considered very advantageous. With the method according to the invention, it is also possible to set an almost constant state of charge of the battery at an almost constant rotational speed of the internal combustion engine. In particular, the injection quantity, the internal torque and/or the indicated pressure of the internal combustion engine are/is regulated during an increase in the load point of the internal combustion engine. This contributes to the operational smoothness of the internal combustion engine and the overall perception of the acoustic aspects of the hybrid vehicle.

In the method according to the invention, the target charging power is therefore determined as a function of various parameters and it is checked whether the actual charging power of the battery at present can reach the target state of charge of the battery in a completely defined time period. If the target state of charge of the battery, i.e. the target energy in relation to the battery, cannot be reached, in particular because of a deviation from the average target charging power, the described upgrade is triggered, so that a change to operating points which do not correspond to optimum values in terms of efficiency and/or noise emission is also permitted on the overall characteristic curve of the internal combustion engine and the entire drive train. Of importance in hybrid vehicles are the efficiency of the internal combustion engine and the electric machine and the drive train components that act between them. However, in acoustic terms, the abnormality is mostly due to the internal combustion engine and secondly also to the transmission.

The following requirements are therefore taken into account by means of the method according to the invention: as far as possible, electrical energy is generated from the fuel using only the movement of the load point, which is particularly advantageous in terms of energy and acoustics. The on-board electrical system requirements of the hybrid vehicle are thus met on average. The method according to the invention therefore comprises a defined upgrading mechanism which can be implemented if necessary, even if more unfavorable load point shifts of the internal combustion engine are available, wherein the method according to the invention is used in the overall characteristic curve of the internal combustion engine, mainly with regard to particularly favorable load point shifts in terms of energy and/or acoustics, in particular not only at a completely defined engine speed.

By means of the method according to the invention, it is thus possible to supply the vehicle electrical system of the hybrid vehicle with a corresponding charging power on average and to achieve a corresponding target charging power in the battery. For example, the energy reserve in the battery can be ensured at a completely defined point in time for a defined discharge measure. As a whole, a particularly efficient supply of electrical energy for a hybrid vehicle can be achieved by means of the method according to the invention.

An advantageous embodiment of the invention provides that the target state of charge of the battery is predefined as a function of the current state of charge of the battery, the power demand of an auxiliary load of the hybrid vehicle and/or the speed of the hybrid vehicle. The target state of charge of the battery at the fully determined future point in time can thus be determined taking into account the current state of charge of the battery. Depending on, for example, the power requirement of the auxiliary loads of the present hybrid vehicle, the target state of charge can likewise be set correspondingly adapted to the future, completely determined point in time. And, taking into account the speed of the hybrid vehicle, it is also possible to set the target state of charge particularly ideally at a future defined point in time.

A further advantageous embodiment of the invention provides that the range of the characteristic curves classified as advantageous is expanded in the direction of a stronger noise emission of the internal combustion engine the faster the hybrid vehicle is driven. Since the faster the hybrid vehicle travels, for example, the wind noise and rolling noise of the hybrid vehicle enter the environment more strongly. The characteristic curve range which is listed as advantageous with regard to noise emissions can thus be shifted in the direction of stronger engine noise emissions, without the vehicle occupants perceiving the stronger engine (noise) emissions. Depending on the speed, therefore, the predefined target state of charge can be reached in a simple manner while remaining within the characteristic curve which is currently listed as advantageous with regard to noise emissions.

According to a further advantageous embodiment of the invention, threshold values for efficiency and/or for noise emission are preset, which specify a range of characteristic curves of the internal combustion engine that are listed as advantageous. In this way, the range of the characteristic curves of the internal combustion engine which are listed as advantageous can be clearly described. For example, it is conceivable to preset threshold values for efficiency and/or for noise emission depending on the current driving mode of the hybrid vehicle. If the hybrid vehicle is operated, for example, in a sport mode, the threshold value for efficiency can be lowered relative to a standard value and the threshold value for noise emission can be raised relative to a standard value. Since in the sport mode the driver usually takes particular care whether as much driving power as possible is available, or not, and, conversely, it may also agree with the sound of the internal combustion engine which is present to a certain extent in order to highlight the sport driving characteristics. Thresholds for efficiency and noise emissions may also be preset, for example, based on the current hybrid vehicle environment. It is therefore conceivable, for example, that an environmental region is being traveled through which the hybrid vehicle is to be moved with particularly low emissions of exhaust gases and noise. In this case, the threshold value for efficiency can be raised relative to a standard value and the threshold value for noise emission can be lowered relative to a standard value, for example. By means of the driving mode-dependent and/or environment-dependent adjustment of the threshold value, the necessary load point increase of the internal combustion engine can be adapted in particular to the specific situation.

In a further advantageous embodiment of the invention, it is provided that, if it is determined from the average battery actual charging power obtained within a predetermined time period: if the target state of charge is not reached by a previous increase in the load point, the load point of the internal combustion engine is increased step by step further outside the range of the characteristic curve of the internal combustion engine that is classified as favorable. It is therefore proposed that the load point increase be carried out gradually, so that the internal combustion engine is only moved increasingly further away from a particularly desired operating state of the internal combustion engine in terms of efficiency and/or noise emission, if this is necessary to achieve a predetermined target state of charge. By leaving the ideal operating state of the internal combustion engine individually or slowly, it can be ensured that the internal combustion engine is operated in the ideal or at least approximately ideal operating state for as long as possible. On the one hand, this ensures that the preset target state of charge is also reached as reliably as possible, and on the other hand, this ensures that the charging of the battery takes place in an energy-and sound-optimized manner.

A further advantageous embodiment of the invention provides that the torque limit value of the electric machine is preset with respect to the generator operation of the electric machine, and that the load point increase is carried out only if the torque limit value is not exceeded. Since in generator operation the partial torque of the internal combustion engine is used via the shaft to generate the current for the generator. In other words, the torque limit of the electric machine with respect to the operation of its generator is taken into account, so that only possible and reasonable load point shifts of the internal combustion engine are also observed and implemented, so that the partial torque is not lost too much. In this way, it is likewise possible to ensure that the electrical energy or power necessary for achieving the target state of charge is generated in the manner of a generator only by means of a particularly advantageous shifting of the load point.

According to a further advantageous embodiment of the invention, provision is made for predictive data to be made which describe future changes in the state of charge of the battery caused by regeneration, said predictive data being taken into account when the load point of the internal combustion engine is increased and/or when the target state of charge is predefined. With knowledge of the future potential for regeneration, the load point increase of the internal combustion engine can therefore be adjusted accordingly. The target state of charge can likewise be set accordingly with knowledge of the future regeneration potential. If, for example, it is anticipated that a relatively large amount of electrical energy is reused by regeneration, the increase in the load point of the internal combustion engine can be carried out moderately such that the range of the characteristic curve of the internal combustion engine which is listed as advantageous is completely absent or only slightly removed. The target state of charge can likewise be selected to be low or high accordingly with knowledge of the future regeneration potential. Since the necessary load point increase is also dependent on the preset target state of charge, this can help to achieve particularly efficient hybrid vehicle operation.

In a further advantageous embodiment of the invention, provision is made for prediction data relating to an operating strategy of the hybrid vehicle (1) to be made, which describes when the hybrid vehicle is driven in the future by means of the electric machine and/or by means of the internal combustion engine, said prediction data relating to the operating strategy being taken into account when the load point of the internal combustion engine increases and/or when the target state of charge is preset. If, for example, it is anticipated that in the near future the electric machine of the hybrid vehicle will be less, or even not used at all, for driving the hybrid vehicle, it is therefore possible to carry out the increase in the load point of the internal combustion engine relatively moderately and/or to select the target state of charge relatively low immediately. Conversely, if it is foreseen that the electric machine is used very much for driving the hybrid vehicle, the opposite measure can be taken exactly.

A further advantageous embodiment of the invention provides that the road profile of the hybrid vehicle to be covered is taken into account when the load point of the internal combustion engine is increased and/or when the target state of charge is preset. In this way, the future energy demand of the hybrid vehicle can be predicted particularly precisely in order to match the load point increase and/or to match the target state of charge preset value immediately.

According to a further advantageous embodiment of the invention, a driver characteristic (profile) of the driver of the hybrid vehicle is taken into account when the load point of the internal combustion engine is increased and/or when the target state of charge is preset. If it is clearly found from the driver characteristics that the driver is a relatively free driver, the load point increase can be carried out, for example, moderately or the target state of charge can be selected to be relatively low. If the driver characteristic is a driving mode with very high mobility, the opposite action can be taken, for example. A particularly efficient provision of electrical energy for the hybrid vehicle can thus be achieved taking into account the respective driver characteristics.

The control device according to the invention for a hybrid vehicle is designed to carry out the method according to the invention or an advantageous embodiment of the method according to the invention. Advantageous embodiments of the method according to the invention can be considered as advantageous embodiments of the control device according to the invention and vice versa, wherein the control device has in particular means for carrying out the method steps.

The hybrid vehicle according to the invention comprises the control device according to the invention or an advantageous embodiment of the control device according to the invention.

Further advantages, features and details of the invention emerge from the following description of preferred embodiments and from the figures. The features and feature combinations cited above in the description and those listed later in the description of the figures and/or shown in the figures individually can be used not only in the respectively given combination but also in other combinations or individually without leaving the scope of the invention.

Drawings

In the figure:

fig. 1 shows a very schematic view of a hybrid vehicle comprising an electric machine, a battery and an internal combustion engine; and

fig. 2 shows a consumption characteristic of the internal combustion engine, wherein the characteristic ranges classified as favorable and less favorable with respect to the efficiency of the internal combustion engine and the engine load point shift are schematically shown.

Detailed Description

A hybrid vehicle 1 is shown in a very schematic view in fig. 1. The hybrid vehicle 1 comprises an internal combustion engine 2, an electric machine 3, a battery 4 for supplying the electric machine of the hybrid vehicle 1 and an on-board electrical system, not shown in detail, a transmission 5 and a control device 6 for controlling the generator operation of the electric machine 3 for charging the battery 4.

In the present case, a hybrid vehicle 1 with parallel hybrid drive units is shown. The following description of operating the hybrid vehicle 1 is not limited to a parallel hybrid system, but can also be used in a series hybrid system or in a split-power (leistingsgverzweiten) hybrid system. The hybrid vehicle 1 may be, for example, a moderate hybrid vehicle or may also be a full hybrid vehicle.

Fig. 2 shows a consumption characteristic curve 7 for the internal combustion engine 2. The consumption characteristic curve 7 is also referred to as a shell curve, a shell curve or an efficiency characteristic curve and shows the specific fuel consumption/specific fuel consumption as a function of the effective mean pressure and rotational speed of the internal combustion engine 2. The characteristic curve is defined on the abscissa by the minimum rotational speed and the maximum rotational speed and on the ordinate by the full load curve 8 of the internal combustion engine 2. The lines with the same specific fuel consumption form a shell-shaped pattern here and are therefore also referred to as "shell-shaped diagrams".

A method for operating the hybrid vehicle 1 is explained in detail below, in which method the load point of the internal combustion engine 2 is increased for driving the electric machine 3 in generator mode for charging the battery 4. The target state of charge of the battery 4 at a future point in time is first preset on the basis of a plurality of parameters which determine the electrical power demand of the hybrid vehicle 1. The target state of charge of the battery 4 may be preset, for example, according to the current state of charge of the battery 4, according to the power demand of the auxiliary loads of the hybrid vehicle 1, and/or the speed of the hybrid vehicle 1. It is also possible to provide prediction data which describe or predict future state of charge changes of the battery 4 caused by the regeneration, wherein the prediction data are taken into account when setting the target state of charge. Furthermore, predictive data can also be provided about the operating strategy of the hybrid vehicle 1, which describes or predicts when the hybrid vehicle 1 will be driven in the future by means of the electric machine 3 and/or by means of the internal combustion engine 2. The prediction data relating to the operating strategy can likewise be taken into account when presetting the target state of charge of the battery 4. Furthermore, the road characteristics to be covered, which are also ahead of the hybrid vehicle 1, and the driving characteristics of the driver of the hybrid vehicle 1 may also be taken into account when setting the target state of charge.

Subsequently, a target charging power required for the battery 4 for achieving a preset target state of charge of the battery 4 is determined. The load point of the internal combustion engine 2 is initially increased by means of the control device 7 as a function of the determined target charging power only in the range 9 of the characteristic curve of the internal combustion engine 2 which is listed as advantageous with regard to efficiency and/or noise emission. The load point of the internal combustion engine 2 is increased further away from the characteristic curve range 9 listed as favorable toward the characteristic curve range 10 with a reduced advantage only if: the predetermined target state of charge is not reached at the predetermined future point in time, as determined from the average actual charging power of battery 4 obtained, only by increasing the load point in the range 9 of the characteristic curve that is listed as advantageous.

If it is determined from the average actual charging power of the battery 4 acquired within a predetermined time period that the target state of charge is not reached by the previous load point increase, the load point of the internal combustion engine 2 is increased further outside the range 9 of the characteristic curve of the internal combustion engine 2, which is classified as advantageous. In this case, the torque limit of the electric machine 3 with respect to its generator operation is always taken into account and the load point increase is only carried out to such an extent that the torque limit is not exceeded.

The electrical energy or power necessary for achieving the preset target state of charge of the battery at the completely determined future point in time, if it is not accumulated, for example, due to regeneration, is achieved by an optimized operating point shift of the internal combustion engine 2. The following shifts within the characteristic curve 7 are particularly advantageous here: closer to each other than the consumption line and brought into a state without abnormality in terms of acoustics. The additional movement is more advantageous if the hybrid vehicle 1 is in motion than in the motionless state of the hybrid vehicle 1. The almost constant state of charge of the battery 4 is set at the most constant possible rotational speed of the internal combustion engine 2 by means of the method for operating the hybrid vehicle 1. The injection quantity, the internal torque or the indicated pressure of the internal combustion engine 2 is adjusted in particular in accordance with the deviation from the actually achieved average actual charging power. This contributes to the operational smoothness of the internal combustion engine 2 and the overall feeling in the acoustics of the hybrid vehicle 1.

In this case, if the charging power cannot be brought to the target charging power in the characteristic curve range 9 which is listed as advantageous, an upgrade is started, which is therefore increasingly disadvantageous, and a shift is made in the consumption characteristic curve 7 with regard to efficiency and/or acoustics. The operating point is therefore shifted over the entire consumption characteristic curve 7 only when this is actually necessary, which does not correspond to an optimum value for efficiency and/or acoustics. The required electrical energy or power is also produced by the fuel using only a movement that is particularly advantageous in terms of energy and acoustics, wherein the electrical on-board electrical system requirements can be met on average. According to the specified upgrading scheme, less favorable load point shifts are used if necessary, wherein the complete consumption characteristic curve 7 is used primarily at the energy-favorable load point shifts and not only at a completely defined rotational speed. Thus, a particularly efficient provision of electric energy in the hybrid vehicle 1 can be achieved.