DE102020119127A1 - Method for operating a motor vehicle and corresponding motor vehicle - Google Patents

Abstract

The invention relates to a method for operating a motor vehicle (1) which has a body (2), a drive device having an electric drive unit and an energy store (6) electrically connected to the drive unit for temporarily storing electrical energy. It is provided that the energy store (6) is attached to the body (2) via an actuator device (7) and can be displaced into different positions with respect to the body (2) by means of the actuator device (7) while the motor vehicle (1) is being driven. depending on an operating state variable of the motor vehicle (1), one position is selected from the different positions of the energy store (6) and set on the actuator device (7) to move the energy store (6) into the selected position. The invention also relates to a motor vehicle (1).

Description

The invention relates to a method for operating a motor vehicle, which has a body, a drive device having an electric drive assembly, and an energy store electrically connected to the drive assembly for temporarily storing electrical energy. The invention also relates to a motor vehicle.

From the prior art, for example, the publication DE 10 2013 003 918 B3 known. This describes a device having a vehicle, comprising at least one electric drive device for driving the vehicle and a first high-voltage battery that can be electrically connected to the electric drive device, which electric drive device and which first high-voltage battery are installed in the vehicle for the intended operation of the vehicle, and at least a second high-voltage battery designed independently of the first high-voltage battery, which can be temporarily arranged in or on the vehicle for the intended operation of the vehicle. A method for the device is also explained, in which the second high-voltage battery is coupled mechanically and electrically to the vehicle in order to increase the range of the vehicle. Furthermore, in the pamphlet EP 2 420 418 A1 explains a battery exchange station.

The object of the invention is to propose a method for operating a motor vehicle which has advantages over known methods, in particular improving the driving dynamics of the motor vehicle and/or the safety of the motor vehicle.

According to the invention, this is achieved with a method for operating a motor vehicle having the features of claim 1 . It is provided that the energy store is fastened to the body via an actuator device and can be displaced into different positions with respect to the body by means of the actuator device while the motor vehicle is being driven, with one position being selected from the different positions of the energy store and depending on an operating state variable of the motor vehicle is set to move the energy store in the selected position on the actuator device.

The method described is used to operate the motor vehicle. The motor vehicle is to be understood as meaning a vehicle which is driven by means of the drive device and is not tied to rails. The motor vehicle is therefore, for example, a motor vehicle, a motorcycle or a tractor. If the motor vehicle is designed as a motor vehicle, the motor vehicle is present, for example, as a passenger car or as a truck. The motor vehicle has the body, the drive device and the energy store as essential components. The body is designed as a self-supporting body, so it includes both a body and a chassis of the motor vehicle.

The drive device is used to drive the motor vehicle, ie to provide a drive torque aimed at driving the motor vehicle. In order to generate the drive torque, the drive device has the drive assembly, which is designed as an electric drive assembly and is in the form of an electric traction machine or at least has one. The drive unit is drive-connected to at least one wheel axle of the motor vehicle and/or at least one wheel of the motor vehicle, for example via at least one clutch, for example a starting clutch, and/or a vehicle transmission. With the aid of the vehicle transmission, one of several different transmission ratios can be set between the drive unit and the wheel axle or the wheel.

Electrical energy is required to operate the electric drive unit. This is at least temporarily taken from the energy store, which is provided and set up for the temporary storage of electrical energy. The energy store is electrically connected to the electric drive unit. The electrical energy temporarily stored in the energy store is therefore used at least temporarily to operate the drive unit and therefore to drive the motor vehicle. Of course, provision can be made for at least one further drive unit to be a component of the drive device in addition to the drive unit. In this case, the drive device is particularly preferably configured in such a way that the drive unit and the further drive unit jointly provide the drive torque aimed at driving the motor vehicle, at least at times. For example, the additional drive unit is also in the form of an electric traction machine or alternatively in the form of an internal combustion engine.

Provision could now be made for the energy store to be rigidly connected to the bodywork or rigidly fastened to it, at least while the motor vehicle is being driven. At best, the energy storage for an off be removed from the body to replace the energy storage device. For this purpose, the rigid connection of the energy store to the body is released, the energy store is removed from the body and replaced by another energy store. This is again rigidly attached to the body. However, the rigid attachment causes disadvantages with regard to the driving dynamics of the motor vehicle, since the energy store has a considerable weight and thus has a significant effect on a center of gravity of the motor vehicle.

For this reason, provision is made for the energy store to be attached to the body via the actuator device. The actuator device is used to shift the energy store into different positions with respect to the body, particularly while the motor vehicle is being driven. In other words, the actuator device can be operated to displace the energy store into at least one position selected from a plurality of positions while the motor vehicle is being driven, namely relative to the body. However, a shift can also take place when the motor vehicle is stationary.

During driving operation, for example, the drive unit is operated in such a way that it provides a non-zero drive torque for driving the vehicle. Additionally or alternatively, a driving speed of the motor vehicle, ie a speed at which the motor vehicle moves in relation to a ground, is different from zero. It is therefore not intended to use the actuator device, for example, to replace the energy store, in particular when the motor vehicle is stationary.

Rather, the actuator device should also be used to displace the energy store with respect to the body when the motor vehicle is stationary, namely as a function of the operating state variable of the motor vehicle. For this purpose, a position of the energy store relative to the body is selected from a number of different positions as a function of the operating state variable, and the energy store is moved to the selected position. For this purpose, the actuator device for moving the energy store is set to the selected position. After the setting, the actuator device moves the energy store relative to the body in the direction of the selected position and finally into the selected position.

The described procedure for operating the motor vehicle enables the driving dynamics of the motor vehicle to be optimized during driving. For this purpose, the energy store is shifted, for example, to adjust the center of gravity of the motor vehicle. Provision can thus be made for the center of gravity of the motor vehicle to be set lower at a higher driving speed than at a lower driving speed by correspondingly shifting the energy store. In other words, the energy store is arranged in a first position at a higher first driving speed and in a second position at a lower second driving speed. The first position is chosen such that the center of gravity of the motor vehicle is lower than in the second position, in particular the energy store is arranged further away from the body in the first position than in the second position. By lowering the center of gravity at higher driving speeds, high driving dynamics and also high safety of the motor vehicle are realized.

A development of the invention provides that the different positions differ at least in part with regard to a distance of the energy store from the body and/or an angle of inclination of the energy store with respect to the body in a longitudinal direction of the motor vehicle and/or an angle of inclination of the energy store with respect to the body in a transverse direction of the Distinguish motor vehicle. The distance of the energy store is to be understood in particular as a distance between a geometric center of gravity of the energy store and a geometric center of gravity of the body in the vertical direction. The angle of inclination in the longitudinal direction of the motor vehicle is an angle of inclination with respect to a longitudinal axis of the motor vehicle and can also be referred to as the roll angle. The angle of inclination in the transverse direction of the motor vehicle is the angle of inclination with respect to a transverse axis of the motor vehicle and can accordingly also be referred to as the pitch angle.

The actuator device is designed, for example, in such a way that it only enables the distance between the energy store and the body to be adjusted while the roll angle and pitch angle remain the same. However, it can also be provided that both the distance and the roll angle are adjustable, whereas the pitch angle is identical for all different positions. It can also be provided that the distance and the pitch angle are adjustable, whereas the roll angle is identical for all different positions. However, a configuration of the actuator device which enables the distance, the roll angle and the pitch angle to be set is particularly preferred. A particularly flexible adjustment of the position of the energy store with respect to the body is dependent on this speed of the operating state variable of the motor vehicle possible.

A further development of the invention provides that the actuator device has a plurality of actuators which act on the energy storage device at a distance from one another on the one hand and on the body on the other hand and are controlled to move the energy storage device into the selected position. Each of the actuators preferably enables the energy store to be displaced with respect to the body independently of the other actuators in each case.

For this purpose, the actuators act on the energy store at a distance from one another. For example, there are two actuators, these acting on opposite sides of the energy storage device. Particularly preferably, however, three or four actuators are part of the actuator device, with at least two of the actuators acting on the same side of the energy store. A configuration is particularly preferred in which two of the actuators act on a front side and on a rear side of the energy store.

Each of the actuators is connected to the body on the side facing away from the energy store. For example, the actuators are articulated either on the energy store or on the body or on both in order to enable the independent displacement described above in a particularly large area. The configuration of the actuator device described and the corresponding procedure enable a particularly flexible adjustment of the position of the energy store with respect to the body as a function of the operating state variable of the motor vehicle.

A development of the invention provides that screw drive actuators are used as actuators. The screw drive actuators are to be understood as meaning actuators which have a drive, in particular an electric drive, and a screw drive. The drive is connected to the energy store or the body in terms of drive technology via the screw drive. The screw drive can be designed, for example, as a ball screw drive or as a roller screw drive, in particular as a planetary roller screw drive. For example, it has a threaded spindle and a spindle nut arranged on the threaded spindle. The threaded spindle and the spindle nut interact in such a way that a rotary movement of the threaded spindle causes a translatory movement of the spindle nut or, conversely, a rotary movement of the spindle nut causes a translatory movement of the threaded spindle. Such a configuration of the actuators enables the energy store to be moved particularly quickly and precisely. The actuators, in particular the screw drive actuators, are particularly preferably designed to be self-locking, so that energy only has to be used to move the energy store, but not to hold the selected and set position.

A further development of the invention provides that the displacement of the energy storage device is limited by means of the actuator device in such a way that the energy storage device is always at a predetermined distance from a subsurface supporting the motor vehicle. The motor vehicle is arranged on the ground, in particular it is supported by the at least one wheel or a plurality of wheels on the ground. The actuator device is designed in such a way that the energy store can be displaced even if the distance between the body and the ground is constant. It is therefore not intended to move the energy store with respect to the ground by moving the body with respect to the ground, but the energy store is shifted relative to the body.

Relocating the energy store with respect to the body usually also results in a relocation of the energy store with respect to the ground, so that the distance between the energy store and the ground changes. The actuator device is designed and/or controlled in such a way that the distance between the energy store and the ground always corresponds at least to the predetermined distance. For example, a mechanical limitation of the displacement of the energy store is implemented and implemented in the actuator device.

However, provision can also be made for the actuator device to fundamentally enable the energy store to be relocated down to the ground. In this case, it is preferably provided that the actuator device is controlled at least while the motor vehicle is being driven in such a way that the distance between the energy store and the ground always corresponds at least to the predetermined distance. This reliably prevents the motor vehicle from touching down on the ground. On the other hand, when the motor vehicle is stationary, the energy store can be lowered to the ground, for example to replace the energy store.

A development of the invention provides that one of the following variables is used as the operating state variable: driving speed of the motor vehicle, longitudinal inclination angle of the motor vehicle zeugs, bank angle of the motor vehicle, steering angle of the motor vehicle, side slip angle of the motor vehicle, state of charge of the energy storage device and safety status of the motor vehicle. The driving speed is to be understood as meaning the speed of the motor vehicle at which it is moving on the ground.

The pitch angle is the angle of inclination of the motor vehicle around its longitudinal axis, i.e. its roll angle. The bank angle is the angle of inclination of the motor vehicle around the transverse axis, i.e. its pitch angle.

The pitch angle and the roll angle may be relative to the ground. However, it is also possible for the longitudinal inclination angle and the transverse inclination angle to be determined in a geodetic reference system, so that the longitudinal inclination angle depends, for example, on an incline of the ground.

The steering angle corresponds, for example, to an average wheel steering angle of a steerable wheel axle of the motor vehicle. The sideslip angle denotes the angle between a direction of movement of the motor vehicle in its center of gravity and the longitudinal axis of the motor vehicle. The state of charge indicates, for example, whether the energy store is being charged or at least should be charged, or whether normal driving operation of the motor vehicle is intended.

The safety status describes, for example, a risk to the motor vehicle, for example due to internal or external influences. The safety status preferably describes whether the safety of the motor vehicle is endangered by the energy store. For example, the safety status indicates such a risk to the motor vehicle as soon as a fire in the energy store is detected. Provision is preferably made for the actuator device to be activated in order to remove the energy storage device from the body as soon as the danger to the motor vehicle from the energy storage device has been recognized. In this case, a maximum possible distance between the energy store and the body is particularly preferably set with the aid of the actuator device.

Controlling the actuator device or the actuators as a function of at least one of the variables mentioned enables particularly good driving dynamics of the motor vehicle and/or an improvement in safety. Of course, it is particularly preferable for several or even all of the variables mentioned to be taken into account when selecting the position from the different positions of the energy store. Here, the several sizes can be prioritized differently.

A further development of the invention provides that the energy storage device has an energy receiving device for wirelessly charging the energy storage device and is relocated together with the energy receiving device in the direction of an energy transmission device for wirelessly charging the energy storage device for charging the energy storage device. A wireless charging device has the power receiving device and the power transmitting device. The energy receiving device is part of the energy store or is at least arranged on the energy store. Accordingly, the energy receiving device can be moved together with the energy store.

The energy transmission device, on the other hand, is a stationary device. It is known, for example, that to charge the energy store of the motor vehicle, the motor vehicle is arranged above the energy transmission device and this is subsequently shifted in the direction of the motor vehicle in order to reduce a distance between the energy transmission device and the energy reception device. Subsequently, with the aid of the energy transmission device, energy is transmitted to the energy reception device, which energy is supplied to the energy store in order to charge it.

The charging of the energy store can be further improved in terms of efficiency by moving the energy receiving device together with the energy store in the direction of the energy transmitting device, so that a particularly small distance is realized between the energy receiving device and the energy transmitting device. Provision is particularly preferably made for the energy transmission device to be completely dispensed with, so that the energy transmission device can be run over with the motor vehicle without any problems whatsoever.

Only after the motor vehicle has been arranged via the energy transmission device and, in particular, the energy reception device has been arranged above the energy transmission device, is the energy reception device moved together with the energy storage device in the direction of the energy transmission device and the energy storage device is subsequently charged with energy transmitted via the energy transmission device and the energy reception device. As already explained, this procedure enables a particularly high charging efficiency.

The invention also relates to a motor vehicle, in particular for carrying out the method according to the statements made within the context of this Description, with a body, with a drive device having an electric drive unit and with an energy store electrically connected to the drive unit for temporarily storing electrical energy. It is provided that the energy storage device is attached to the body via an actuator device and can be moved into different positions with respect to the body by means of the actuator device while the motor vehicle is being driven, the motor vehicle being provided and set up for this purpose, depending on an operating state variable of the motor vehicle from the to select a position from different positions of the energy store and to adjust it to move the energy store into the selected position on the actuator device.

The advantages of such a procedure or such a design of the motor vehicle have already been pointed out. Both the motor vehicle and the method for operating it can be further developed according to the statements made within the scope of this description, so that reference is made to them in this respect.

A development of the invention provides that the energy store is arranged under the body. In other words, the energy store is between the body and the ground. This does not mean that the energy store is arranged laterally next to the body and extends next to the body in the direction of the ground, but the energy store is located completely below the body. For example, the body has a floor panel that closes it off in the direction of the ground. The energy store is now arranged below this floor panel. For example, the floor panel has a recess for at least partially accommodating the energy store. The energy store is particularly preferably arranged approximately centrally under the body or under the motor vehicle. The configuration described enables the center of gravity of the motor vehicle to be influenced particularly effectively by moving the energy store.

A further development of the invention provides that the energy store is arranged between the wheel axles of the motor vehicle and/or between two wheels of a wheel axle, viewed in section. Viewed in longitudinal section with respect to the longitudinal axis of the motor vehicle, the energy store is therefore located between the two wheel axles. In contrast, in cross section, along the transverse axis, it is between the two wheels of the wheel axle, in particular between the wheels of several wheel axles. This arrangement enables the center of gravity of the motor vehicle to be set particularly effectively.

• Figur eine schematische Darstellung eines Kraftfahrzeugs, welches über eine Karosserie, eine elektrische Antriebseinrichtung sowie einen elektrischen Energiespeicher verfügt.

The invention is explained in more detail below with reference to the exemplary embodiments illustrated in the drawing, without the invention being restricted. It shows the only

• Figure shows a schematic representation of a motor vehicle which has a body, an electric drive device and an electric energy store.

The figure shows a schematic representation of a motor vehicle 1. This has a body 2, which is supported on a base 5 via a plurality of wheels 3 of two wheel axles 4. The motor vehicle 1 has a drive device, not shown here, which is used at least temporarily to drive the motor vehicle. The drive device has an electric drive unit which is electrically connected to an energy store 6 of the motor vehicle 1 . Electrical energy temporarily stored in the energy store 6 is used at least temporarily to operate the electric drive assembly and thus to drive the motor vehicle 1 .

The energy store 6 is attached to the body 2, namely via an actuator device 7. This has several actuators 8, which are designed as screw drive actuators in the exemplary embodiment shown here. Each of the actuators 8 has at least one new threaded spindle and a spindle nut 10 . The threaded spindle 9 can be driven using a drive 11 . The drive 11 is controlled by a control unit 12 and is electrically connected to it for this purpose.

The actuator device 7 is provided and set up to displace the energy store 6 with respect to the body 2 while the motor vehicle 1 is being driven, that is to say to bring it into different positions. In this case, one position is selected from a number of different positions and the actuator device 7 is actuated in order to move the energy store 6 into the selected position. The position is selected from the plurality of positions as a function of an operating state of the motor vehicle or an operating state variable.

A speed of the motor vehicle, a pitch angle, a roll angle, a steering angle, a side slip angle or a safety state, for example, is used as the operating state variable. A state of charge of the energy store 6 can also serve as an operating state variable. For example, it is provided that Energy store 6 further lower at higher driving speeds than at lower driving speeds, so that the center of gravity of the motor vehicle 1 is lower at the higher driving speeds.

Provision can also be made to displace the energy store 6 while the motor vehicle 1 is cornering in such a way that a centrifugal force acting on the motor vehicle 1 as a result of cornering is counteracted. As a result, high driving dynamics of the motor vehicle 1 are achieved. In addition or as an alternative, provision can be made for the energy store 6 to be moved away from the body 2 if a fire in the energy store 1 is detected. This considerably increases the safety of the motor vehicle 1 .

reference list

1

motor vehicle

2

body

3

wheel

4

wheel axle

5

underground

6

energy storage

7

actuator device

8th

actuator

9

lead screw

10

spindle nut

11

drive

12

control unit

QUOTES INCLUDED IN DESCRIPTION

This list of documents cited by the applicant was generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Patent Literature Cited

• DE 102013003918 B3 [0002]
• EP 2420418 A1 [0002]

Claims (10)

Method for operating a motor vehicle (1), which has a body (2), a drive device having an electric drive unit and an energy store (6) electrically connected to the drive unit for temporarily storing electrical energy, characterized in that the energy store (6) has an actuator device (7) is attached to the body (2) and can be moved into different positions with respect to the body (2) by means of the actuator device (7) while the motor vehicle (1) is being driven, wherein depending on an operating state variable of the motor vehicle (1) a position is selected from the different positions of the energy store (6) and is set on the actuator device (7) in order to move the energy store (6) into the selected position. procedure after claim 1 , characterized in that the different positions differ at least in part with regard to a distance of the energy store (6) from the body (2) and/or an angle of inclination of the energy store (6) with respect to the body (2) in a longitudinal direction of the motor vehicle (1) and / or an angle of inclination of the energy store (6) with respect to the body (2) in a transverse direction of the motor vehicle (1). Method according to one of the preceding claims, characterized in that the actuator device (7) has a plurality of actuators (8), which each act at a distance from one another on the energy store (6) on the one hand and on the body (2) on the other hand and for displacing the energy store (6 ) can be actuated to the selected position. Method according to one of the preceding claims, characterized in that screw drive actuators are used as actuators (8). Method according to one of the preceding claims, characterized in that the displacement of the energy store (6) is limited by means of the actuator device (7) in such a way that the energy store (6) is always at a predetermined distance from a base (5) carrying the motor vehicle (1). having. Method according to one of the preceding claims, characterized in that one of the following variables is used as the operating state variable: driving speed of the motor vehicle (1), longitudinal inclination angle of the motor vehicle (1), transverse inclination angle of the motor vehicle (1), steering angle of the motor vehicle (1), sideslip angle of the vehicle Motor vehicle (1), state of charge of the energy store (6) and safety status of the motor vehicle (1). Method according to one of the preceding claims, characterized in that the energy store (6) has an energy receiving device for wirelessly charging the energy store (6) and for charging the energy store (6) together with the energy receiving device in the direction of an energy transmitting device for wirelessly charging the energy store (6 ) is relocated. Motor vehicle (1), in particular for carrying out the method according to one or more of the preceding claims, with a body (2), with a drive device having an electric drive unit and with an energy store (6) electrically connected to the drive unit for temporarily storing electrical energy, characterized characterized in that the energy store (6) is attached to the body (2) via an actuator device (7) and can be displaced into different positions with respect to the body (2) by means of the actuator device (7) while the motor vehicle (1) is being driven, the Motor vehicle (1) is provided and set up to select a position from the different positions of the energy store (6) depending on an operating state variable of the motor vehicle (1) and to move the energy store (6) into the selected position on the actuator device (7) set. motor vehicle after claim 8 , characterized in that the energy store (6) is arranged under the body (2). Motor vehicle according to one of the preceding claims, characterized in that the energy store (6) is arranged between wheel axles (4) of the motor vehicle (1) and/or between two wheels (3) of a wheel axle (4), viewed in section.

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