DE102021104692A1 - Driver assistance system and method for operating a driver assistance system - Google Patents

Abstract

The invention relates to a driver assistance system (1) for a motor vehicle (3), the driver assistance system supporting driving operation of the motor vehicle (3) with a first degree of automation and with a second degree of automation. In the first degree of automation, a vehicle occupant of the motor vehicle (3) intervenes or can briefly intervene in the longitudinal and/or lateral guidance of the motor vehicle (3) by operating an operating element (11, 12). In the second degree of automation, the longitudinal and/or lateral guidance can be carried out automatically without intervention by the vehicle occupant using the operating element (11, 12). The driver assistance system (1) is set up to decouple the operating element (11, 12) from the longitudinal and/or transverse guidance when the motor vehicle (3) is operated with the second degree of automation; and during a transition from the first degree of automation to the second degree of automation during a first transition phase, in which the operating element (11, 12) is already decoupled from the longitudinal and/or transverse guidance, using the operating element (11, 12) to provide haptic feedback produce, which gives the vehicle occupant the feeling of still being able to act on the longitudinal and/or transverse guidance by means of the operating element (11, 12).

Description

The invention relates to a driver assistance system for a motor vehicle and a method for operating a driver assistance system for a motor vehicle. Furthermore, the invention relates to a computer program and a computer-readable medium that support such a driver assistance system or such a method.

The invention can be used in particular in the context of a driver assistance system (FAS), which enables at least partially automated driving, preferably up to fully automated driving (VAF), of the vehicle.

In the context of this document, the term "automated driving" can be understood as driving with automated longitudinal or lateral guidance or autonomous driving with automated longitudinal and lateral guidance. The term "automated driving" as used in this document includes automated driving with any degree of automation. Exemplary degrees of automation are assisted, partially automated, highly automated or fully automated driving. These degrees of automation were defined by the Federal Highway Research Institute (BASt) (see BASt publication "Research compact", issue 11/2012).

With assisted driving, the driver constantly performs longitudinal or lateral guidance, while the system takes over the other function within certain limits. With semi-automated driving (TAF), the system takes over longitudinal and lateral guidance for a certain period of time and/or in specific situations, whereby the driver has to constantly monitor the system, as with assisted driving. With highly automated driving (HAD), the system takes over longitudinal and lateral guidance for a certain period of time without the driver having to constantly monitor the system; however, the driver must be able to take control of the vehicle within a certain period of time. With fully automated driving (VAF), the system can automatically handle driving in all situations for a specific application; a driver is no longer required for this application.

The four levels of automation mentioned above, as defined by BASt, correspond to SAE levels 1 to 4 of the SAE J3016 standard (SAE - Society of Automotive Engineering). For example, according to BASt, highly automated driving (HAF) corresponds to level 3 of the SAE J3016 standard. Furthermore, SAE J3016 also provides SAE Level 5 as the highest degree of automation, which is not included in the BASt definition. SAE Level 5 corresponds to driverless driving, in which the system can automatically handle all situations like a human driver throughout the journey; a driver is generally no longer required.

In vehicles that are equipped with automated driver assistance functions up to level 4 (fully automated driving - VAF), the accelerator pedal, brake pedal and steering wheel are not required when VAF is activated. In this case, the driver no longer has to monitor the driving task and therefore no longer has to intervene in the driving process.

In today's vehicles equipped with driver assistance systems, the accelerator pedal, brake pedal and steering wheel are usually installed in such a way that they are in a fixed position relative to the driver. With all of today's driver assistance systems up to and including level 3, the driver must always monitor the driving task and intervene if necessary, so the basic position of the pedals and the steering wheel must not change.

However, this is no longer necessary for driver assistance functions with level 4 and higher, e.g. VAF. Here, the task of driving is completely taken over by the ADAS, i.e. the driver no longer has to monitor the vehicle guidance.

In order to offer the driver more comfort and freedom of movement when the VAF is activated, the pedals can be folded away and the steering wheel retracted. In general, it is possible or at least easier to move the steering wheel and/or pedals in and out or to fold them away by using so-called x-by-wire systems (e.g. steer-by-wire in the case of the steering wheel), which work without a mechanical Transmission line (such as in the form of a mechanical steering column) for the control signals, get by.

Against this background, it is an object of the present invention to specify a driver assistance system or a method that makes a transition between two different degrees of automation, in particular between manual or partially automated driving on the one hand and fully automated driving on the other, as safe and comfortable as possible.

The task is solved by a driver assistance system or by a method according to the independent patent claims. Advantageous embodiments are specified in the dependent claims. It is pointed out that additional features of a claim dependent on an independent claim without the features of the independent patent claim or only in combination with a subset of the features of the independent patent claim can form a separate invention independent of the combination of all features of the independent patent claim, which can be made the subject of an independent patent claim, a divisional application or a subsequent application. This applies equally to the technical teachings explained in the description, which can form an invention independent of the features of the independent patent claims.

A first aspect of the invention relates to a driver assistance system (FAS) for a motor vehicle.

In the context of the present application, the term motor vehicle can in particular be understood to mean a land vehicle that is moved by machine power without being tied to railroad tracks. A motor vehicle in this sense can, for example, be designed as a motor vehicle, motorcycle or tractor.

The ADAS is set up to support (in the sense of enabling) driving operation of the motor vehicle with a first degree of automation and with a second degree of automation.

In the first degree of automation, it is provided (and possibly required) that a vehicle occupant of the motor vehicle intervenes or can intervene briefly in the longitudinal and/or lateral guidance of the motor vehicle by operating an operating element. In particular, with the first degree of automation, it can be provided that the vehicle occupant must at least be ready to intervene in the longitudinal and/or lateral guidance using the control element within a certain time interval if necessary (and possibly upon request by the ADAS), e.g. in driving situations , which the ADAS cannot manage with sufficient reliability in the first degree of automation to guide the vehicle appropriately. The first automation wheel can, for example, be purely manual or merely assisted driving. However, the first degree of automation can also extend up to level 3, i.e. to highly automated driving operations (HAF).

The control element mentioned above can e.g. B. be an element from the following list: a steering wheel; a pedal (e.g. for gas, brake or clutch); a control stick (e.g. in the manner of a joystick). It is also possible for several such operating elements to be provided, which interact with an ADAS according to the invention in the manner described here.

In the second degree of automation, the longitudinal and/or transverse guidance can be carried out automatically without intervention by the vehicle occupant using the operating element. In other words, the second level of automation is a level of automation from level 4 (VAF) upwards.

The ADAS is set up to decouple the operating element from the longitudinal and/or lateral guidance when the motor vehicle is operated with the second degree of automation.

The ADAS is also set up to use the control element to generate haptic feedback during a transition from the first degree of automation to the second degree of automation during a first transitional phase in which the control element is (actually) already decoupled from the longitudinal and/or lateral guidance conveys the feeling to the vehicle occupants that they can still act on the longitudinal and/or lateral guidance by means of the operating element.

In the context of the present document, haptic feedback generated by means of the operating element should be understood to mean that the operating element is set up to give the vehicle occupant, when he/she actuates the operating element, the feeling through force and/or torque feedback that the operating element is lateral and/or longitudinal guidance of the motor vehicle, even if this is actually not the case (e.g. during the first transitional phase and thereafter). The concept of haptic feedback is also known under the term "force feedback" in the field of gaming or fly-by-wire controls in aviation, for example. For example, force feedback is widely used in gaming to achieve a driving experience that is as realistic as possible in a racing simulation.

The invention is based on the finding that the driver of the motor vehicle at the beginning of the transition from the first automation wheel to the second degree of automation (e.g. in the first moment after he has activated a VAF driving mode starting from a manual, assisted, TAF or HAF driving mode) frequently has his hands on the steering wheel and/or his feet in contact with one or more pedals. It would feel uncomfortable and possibly unsafe for the driver if, for example, immediately after he had pressed a button to activate VAF driving mode, the steering wheel suddenly and noticeably no longer had any grip on the road. In order for the transition to be more comfortable and more confidence-inspiring for the driver, the transition should therefore be perceived by the driver not happen suddenly (even if the VAF function is activated immediately at least subordinately and actually takes over the vehicle guidance), but rather be implemented gently. This is made possible by the haptic feedback provided according to the invention on the operating element.

It can also be provided, for example, that an intensity of the haptic feedback decreases over time (e.g. linearly) during the first transition phase. As a result, a transition to the second degree of automation, which the vehicle occupant perceives to be particularly smooth, can be implemented.

To generate the haptic feedback, one or more, e.g. electromechanical, actuators (such as electric motors) can be provided, which are in a mechanical operative connection with the operating element. Mechanisms for generating haptic feedback (force feedback) on control elements, such as steering wheels, pedals or joysticks, are known per se to those skilled in the art. Implementation details for realizing the haptic feedback provided according to the invention on the operating element are therefore not described in detail in the present document.

However, it is pointed out by way of example that if the operating element is a steering wheel with a steer-by-wire function, one or more electric motors are usually present anyway. According to an embodiment proposed here, these can then also be used to generate the haptic feedback on the steering wheel.

For example, during the first transitional phase, in which the vehicle occupant can actually no longer exert any steering effect on the road by operating the steering wheel, the driving behavior can be detected by sensors based on the movement of the wheels. Using the haptic feedback on the steering wheel, the driver can then be given a corresponding steering feel, which suggests that the steering wheel is still coupled to the road.

According to one specific embodiment, the driver assistance system includes a mechanism that is set up to automatically transfer the control element from a use position to a ready position during the transition from the first degree of automation to the second degree of automation, in order to offer the driver's vehicle occupant more comfort and/or freedom of movement when the second degree of automation is activated . For example, the space available to the vehicle occupant in the passenger compartment of the motor vehicle can be increased by moving the control element from the use position to the ready position, by retracting or folding the control element out of the passenger compartment or into a peripheral area of the passenger compartment.

For example, the mechanism may be an electromechanical mechanism and may also include electronic components.

The transfer of the operating element from the usage position to the ready position by means of the mechanism can take place in particular after the end of the first transition phase and (and preferably after a subsequent check for freedom from moments or the like, as described below).

According to a further development, the driver assistance system (by means of suitable sensors and evaluation logic) is set up to check whether the vehicle occupant (physically, i.e. e.g. manually and/or with his feet) acts on the control element and the transfer of the control element into the ready position only under the condition initiate that the vehicle occupant does not (in particular no longer) acts on the control element. This check can take place, for example, in a first test phase, which takes place between the first transition phase and the transfer of the operating element from the use position to the ready position.

If the operating element is a steering wheel or includes a steering wheel, it can be determined in the first test phase, e.g. by checking for freedom from torque, whether the vehicle occupant is gripping the steering wheel or touching it in some other way. If this is the case, the vehicle occupant will generally—voluntarily or involuntarily—act on the steering wheel with (possibly very small) steering torques that can be detected by sensors.

As an alternative or in addition to a check for freedom from torque, a check for changes in the position of the steering wheel and/or steering speeds or changes in steering speed can be carried out, for example, in order to determine whether the vehicle occupant has his hands on the steering wheel. Because the steering wheel is only moved from the use position to the ready position when it has been determined that the vehicle occupant is not (or no longer) holding his/her hands on the steering wheel, it is possible, for example, to prevent his/her hands from being trapped when the steering wheel is moved to the ready position become or similar

If the control is or includes a pedal (such as an accelerator, brake, or clutch ment pedal), in the first test phase it can be detected by sensors, for example, whether the vehicle occupant presses the pedal with one foot, stands with his foot on the pedal or touches the pedal in some other way. For this purpose, for example, position changes of the pedal detected by sensors can be used. For example, it can be provided that the pedal is folded away in the direction of the vehicle floor when transferring from the use position to the ready position. In this case, the fact that the folding away of the pedal is only carried out when it has been determined that the vehicle occupant is no longer in contact with the pedal can be prevented, for example, that a foot of the vehicle occupant when transferring to the ready position under the pedal is jammed.

It is also within the scope of the invention that the control element (preferably after a check has shown that the vehicle occupant is not acting on the control element, as described above) is first automatically transferred to a suitable intermediate position, from which the transition to the stand-by position takes place. In the case of a steering wheel, for example, it can be provided that the steering wheel is first straightened before it is moved to its ready position.

In one embodiment, the mechanism is set up to automatically transfer the operating element from the ready position to the use position when there is a transition from the second degree of automation to the first degree of automation. In other words, the control element can also be automatically adjusted in the opposite direction, e.g. in order to enable the vehicle occupant to intervene in the vehicle guidance using the control element again when changing from fully automated driving to partially automated or manual driving.

It is preferred that the driver assistance system is set up to initially synchronize the control element with a current longitudinal and/or lateral guidance state of the motor vehicle during the transition from the second degree of automation to the first degree of automation, before the control element (again) with the longitudinal and/or or lateral guidance of the motor vehicle is coupled (i.e. before the vehicle occupant can act on the longitudinal and/or lateral guidance using the operating element). For example, in the case that the operating element is or comprises a steering wheel, the steering wheel position can be synchronized with a current wheel position before the steering wheel is coupled to the lateral control of the motor vehicle (i.e. to the wheels).

According to a second aspect of the invention, a method for operating a driver assistance system is proposed.

The method according to the second aspect of the invention can be carried out in particular by means of an ADAS according to the first aspect of the invention. Therefore, embodiments of the method according to the invention can correspond to the advantageous embodiments of the ADAS according to the invention described above and below and vice versa.

In accordance with this, the method includes a transfer (e.g. triggered in response to an operator action by the vehicle occupant) of driving operation of the motor vehicle from a first degree of automation, in which it is provided that a vehicle occupant of the motor vehicle can be activated by actuating an operating element in the longitudinal and / or lateral guidance of the motor vehicle intervenes or can intervene at short notice, to a second degree of automation, in which the longitudinal and/or lateral guidance can be carried out automatically without the vehicle occupant interfering with the operating element, and in which the operating element is decoupled from the longitudinal and/or lateral guidance . During a first transitional phase, in which the control element is already decoupled from the longitudinal and/or transverse guide, the control element generates haptic feedback, which gives the vehicle occupant the feeling of still using the control element on the longitudinal and/or transverse guide to be able to influence.

According to one embodiment, the operating element is automatically transferred from a use position to a ready position during the transition from the first degree of automation to the second degree of automation in order to offer the driver more comfort and/or freedom of movement when the second degree of automation is activated.

The operating element can be moved from the use position to the ready position (and possibly also vice versa) by means of a suitable electromechanical mechanism, for example, as described above with reference to the ADAS according to the invention. With regard to possible properties of the use position and the standby position, reference is also made to the above statements on the ADAS according to the first aspect of the invention.

In a first test phase, before the operating element is moved into the ready position, it is preferably checked whether the vehicle occupant is acting on the operating element. The transfer of the operating element to the ready position is then only initiated under the condition that the vehicle occupant does not act on the control element.

According to a development, the method also includes a transfer of the driving operation from the second degree of automation to the first degree of automation, wherein the control element is automatically transferred from the standby position to the use position during the transition from the second degree of automation to the first degree of automation.

In an advantageous embodiment, it is further provided that the operating element is initially synchronized with a current longitudinal and/or lateral guidance state (e.g. with a current wheel position if the operating element is a steering wheel) of the motor vehicle during the transition from the second degree of automation to the first degree of automation. before the operating element is coupled to the longitudinal and/or transverse guide of the motor vehicle.

A third aspect of the invention is a computer program comprising instructions that cause an ADAS according to the first aspect of the invention to carry out the method steps according to the second aspect of the invention. According to some embodiments, the computer program can also include multiple parts that can each be executed on different computing devices (such as multiple control units) of the ADAS.

For example, according to the first aspect of the invention, the ADAS can include one or more computing devices, in particular control units, for executing the computer program according to the third aspect of the invention, for generating corresponding control signals and for outputting the control signals to suitable actuators in order to carry out the method steps according to the second aspect of the invention.

A fourth aspect of the invention is a computer-readable medium storing a computer program according to the third aspect of the invention.

• 1 zeigt schematisch ein FAS mit beispielhaften Bedienelementen in einer jeweiligen Gebrauchsposition.
• 2 zeigt das FAS aus 1, wobei die Bedienelemente eine jeweilige Bereitschaftsposition einnehmen.
• 3 verdeutlicht beispielhaft und schematisch einen zeitlichen Ablauf in mehreren Phasen bei einem Übergang vom manuellen Fahren zum vollautomatisierten Fahren.
• 4 zeigt beispielhaft und schematisch den Austausch von Steuernachrichten zwischen mehreren Steuergeräten eines FAS bei einem Wechsel vom manuellen Fahren zum vollautomatisierten Fahren.
• 5 verdeutlicht beispielhaft und schematisch einen zeitlichen Ablauf in mehreren Phasen bei einem Übergang vom vollautomatisierten Fahren zum manuellen Fahren.
• 6 zeigt beispielhaft und schematisch den Austausch von Steuernachrichten zwischen mehreren Steuergeräten eines FAS bei einem Wechsel vom vollautomatisierten Fahren zum manuellen Fahren.

The invention will now be explained in more detail using exemplary embodiments and with reference to the accompanying drawings. The features and feature combinations mentioned above or below in the description and/or shown alone in the drawings can be used not only in the combination specified, but also in other combinations or on their own, without departing from the scope of the invention. For example, such aspects and features that relate to the transition from the second degree of automation to the first degree of automation (such as the second transition phase) can also form independent aspects of the invention independently of aspects and features that relate to the transition from the first degree of automation to the second degree of automation.

• 1 shows a schematic of an ADAS with exemplary operating elements in a respective position of use.
• 2 shows the FAS 1 , wherein the controls assume a respective standby position.
• 3 illustrates, by way of example and schematically, a chronological sequence in several phases during a transition from manual driving to fully automated driving.
• 4 shows an example and a schematic of the exchange of control messages between several control units of an ADAS when changing from manual driving to fully automated driving.
• 5 illustrates, by way of example and schematically, a chronological sequence in several phases during a transition from fully automated driving to manual driving.
• 6 shows an example and a schematic of the exchange of control messages between several control units of an ADAS when changing from fully automated driving to manual driving.

the 1 and 2 each show a cross-sectional view of a front area of a motor vehicle 3 with a driver or vehicle occupant. The motor vehicle 3 is equipped with an ADAS 1, which enables the motor vehicle 3 to be driven both with a first degree of automation and with a second, higher degree of automation.

At the first level of automation, which 1 is illustrated, it is, for example, manual driving or partially automated driving up to highly automated driving (HAF or Level 3). For example, assistance functions such as adaptive cruise control (ACC) or steering and tracking assistance (LSA) can be active.

During driving with the first degree of automation, it is necessary for the driver to intervene in the longitudinal and/or lateral guidance of the motor vehicle 3 by actuating one or more operating elements—represented here by a steering wheel 11 and one or more pedals 12—or at least for one such an intervention must be ready at short notice.

At the in 2 The second degree of automation illustrated can in particular be fully automated driving (VAF or level 4). The steering and/or lateral guidance is carried out automatically by the ADAS without the need for intervention on the part of the driver. With the second degree of automation, the driver can therefore divert his attention from what is happening during driving and read a newspaper, for example.

In order to offer the vehicle occupants more comfort and freedom of movement during driving with the second degree of automation (example below: VAF), the pedals can be folded away and the steering wheel retracted in this case, as in 2 shown. For this purpose, the ADAS 1 includes a mechanism that is set up to automatically move the steering wheel 11 and the pedals 12 from a position of use when changing from the first degree of automation to the second degree of automation (see Fig. 1 ) to a ready position (see 2 ) to transfer. The steering wheel 11 and the pedals 12 are retracted or folded out of the passenger compartment or into a peripheral area of the passenger compartment, as in FIG 2 exemplified and illustrated schematically.

The following is with reference to 3 a transition of the actual and the driver's perceived control of the lateral and longitudinal guidance from the driver to the ADAS when changing from manual driving to VAF is described. This transition, which is divided into different phases, can be controlled in whole or in part by a computing device 15 of the ADAS, which computing device 15 can in particular comprise one or more control units, as described below with reference to FIG 4 will be explained in more detail.

In 3 the horizontal axis of the diagram is a time axis, the length ratios of the time sections (phases) shown not being shown to scale.

In a first illustrated phase “1.” the motor vehicle 3 is in manual driving mode. As an alternative to purely manual driving, which is only assumed here as an example, another first degree of automation up to level 3 can also be activated in this phase.

During phase “1.”, which lasts until time “2.”, the driver is responsible for the longitudinal and lateral guidance of motor vehicle 3 and is aware of this. This will in 3 by a solid graph indicating a driver-perceived degree of driver control over vehicle guidance, and by a dashed graph indicating a driver-perceived degree of control of ADAS 1 over operating elements 11, 12: Up to At time "2." the dashed graph remains at zero and the solid graph is constant at a maximum value. During manual operation in phase “1.”, there can be a comparatively rigid coupling of the steering wheel to the wheels and thus to the road (particularly in the perception of the driver).

At time “2.” activation of the second degree of automation (VAF) is initiated. This can be triggered, for example, by an actuation action (such as pressing a button) by the driver. In general, certain conditions must be met for activation of VAF, such as driving within a certain speed range, within a certain acceleration band and/or within a curvature band. This represents only an exemplary selection of possible activation conditions for VAF, which are known per se and which are not the subject of the present invention and are therefore not described in greater detail at this point.

From time "2.", the VAF function of ADAS 1 is immediately active, at least subordinately. This immediately takes over the control of the motor vehicle 3 and is fully responsible from the point in time "2." The operating elements 11, 12 are decoupled from the longitudinal and/or lateral guidance from the point in time “2nd”, from which the motor vehicle 3 is operated at the second degree of automation (VAF).

However, it would feel uncomfortable for the driver if the steering wheel 11 suddenly had no (perceived) grip on the road from time “2.” or if the pedals 12 were (perceptibly) suddenly decoupled from the longitudinal guide of the motor vehicle 3 would. The ADAS 1 is therefore set up during a transition from the first degree of automation (here: manual) to the second degree of automation (here: VAF) during a first transitional phase "3.", in which the operating elements 11, 12 are actually already moved from the longitudinal and or lateral guidance are decoupled to generate haptic feedback on the operating elements 11, 12, which gives the driver the feeling of being able to act on the longitudinal or lateral guidance using the respective operating elements 11, 12.

During the first transitional phase “3.”, the driver still has his hands on the steering wheel 12, for example, while the VAF function is already controlling and possibly works against the steering movement of the driver. At the same time, the driver can no longer exert any steering action on the road and can no longer influence the drive train with the pedals. However, the haptic feedback can temporarily give the driver the feeling that he is still connected to the road or to the drive train.

To generate the haptic feedback, one or more, e.g. electromechanical, actuators (such as electric motors) can be provided, which are in a mechanical operative connection with the respective control element 11, 12. For example, if the steering wheel 12 has a steer-by-wire function, one or more electric motors are present anyway, which can be used to generate the haptic feedback on the steering wheel 12 .

For example, during the first transitional phase “3.”, in which the vehicle occupant can de facto no longer exert any steering effect on the road by operating the steering wheel 12, the driving behavior can be detected by sensors based on the movement of the vehicle wheels. By means of the haptic feedback on the steering wheel 12, the driver can then be given a corresponding steering feel, which suggests to him that the steering wheel 12 is still coupled to the road.

The supposed coupling between the steering wheel 12 and the wheels/road, which can be perceived by the driver and which is conveyed by the haptic feedback, can be reduced over time (for example in a ramp-like manner down to zero). In other words, an intensity of the haptic feedback during the first transition phase "3rd" may decrease over time. The same applies analogously to the coupling of the pedals to the drive train or to the longitudinal guidance of the vehicle, which the driver can perceive. The driver can gradually get used to the "loss of control" in terms of driving the vehicle during the first transitional phase "3rd phase". At the end of the first transition phase, the driver can, for example, turn the steering wheel 11 with essentially no resistance and no longer felt any feedback from the road. In the diagram in 3 This is illustrated schematically by the fact that the solid graph ramps towards zero while the dashed graph ramps up.

For example, a duration of at least 100 ms, in particular at least 200 ms, can be provided for the first transitional phase “3rd”. For example, a duration in the range from 100 ms to 2000 ms can be provided for the first transition phase “3rd”.

The first transitional phase “3rd” is preferably followed by a first test phase “4th” before the respective operating element 11, 12 is actually transferred from its usage position to its ready position. In the first test phase "4.", ADAS 1 uses suitable sensors and evaluation logic to check whether the driver is physically, i.e. e.g. manually or with his feet, acting on the respective operating element 11, 12. In order to move an operating element 11, 12 into the ready position, it is a prerequisite that it is determined in test phase "4." that the driver is no longer acting on the relevant operating element 11, 12, e.g. that he/she takes his hands off the steering wheel took 11.

For example, it can be determined by checking whether there are no moments, whether the driver is touching the steering wheel 11 or touching it in some other way; if this is the case, the driver will in general—voluntarily or involuntarily—act on the steering wheel 11 with (possibly very small) steering torques that can be detected by sensors. As an alternative or in addition to a check for freedom from torque, a check for changes in the position of the steering wheel 11 and/or for steering speeds or changes in the steering speed can be carried out, for example, in order to determine whether the driver has his hands on the steering wheel 11. Such a check can ensure that the driver does not injure himself when the steering wheel 11 is subsequently pulled in.

Alternatively or additionally, in the first test phase “4.” it can be detected by sensors, for example, whether the driver actuates the pedal 12 with one foot, stands on the pedal 12 with his foot or touches the pedal 12 in some other way. Sensor-detected changes in the position of the pedal 12, for example, can be used for this purpose. For example, it can be provided that the pedal 12 is folded away in the direction of the vehicle floor when transferring from the use position to the ready position. In this case, by folding away the pedal 12 only when it has been determined that the driver is not (or no longer) in contact with the pedal 12, it is possible to prevent, for example, a foot of the driver from falling when the pedal 12 is transferred is wedged into the ready position under the pedal 12.

After the first test phase "4." (and in particular if the test has shown that the driver does not act on the relevant control element 11, 12, as described above), the control elements 11, 12 can finally move to their "5th" phase respective stand-by who brought the. It can also be provided that one or more of the operating elements 11, 12 is initially automatically transferred to a suitable intermediate position, from which the transition to the ready position then takes place. For example, the steering wheel 11 can first be straightened before it is moved to its ready position.

According to one embodiment variant, it is also conceivable that such a straightening of the steering wheel 11 is already carried out in the first transition phase "3.", e.g. immediately from the point in time "2.", so that a corresponding steering movement when straightening the steering wheel 11 is slightly counter to any still carried out steering wheel operations of the driver is carried out.

the 4 FIG. 12 illustrates, by way of example and schematically in the form of a message sequence diagram, the exchange of control messages between a plurality of control units of ADAS 1 in the case of the above with reference to FIG 3 explained transition from manual driving to VAF. The example shown relates specifically to a sequence involving the steering wheel 11; for other control elements such as one or more pedals 12, the process can be applied analogously.

In the upper area of the 4 some necessary sub-functions are identified, including a possible partitioning to several control units (control unit 1, control unit 2 and EPS). These control units can be part of the (distributed) computing device 15 of the ADAS 1 mentioned above.

It is preferred that the sub-functions mentioned in the upper left four boxes are partitioned on a steering control unit EPS, as in 4 shown. In this case, the partial function “crossfade” relates to the first transitional phase “3.”, in which, for example, haptic feedback is generated on the steering wheel 12, as further above with reference to FIG 3 was explained.

The sub-functions (longitudinal/transverse control and VAF) mentioned in the top right two boxes can be partitioned on one or more arbitrary control units with corresponding computing and storage resources, whereby a division into a "control unit 1" and a "control unit 2 ' is shown. It is also conceivable that these sub-functions are executed on one and the same control unit.

In general, the in 4 shown allocation of sub-functions to several control units to understand only as an example. Embodiments with other divisions of the sub-functions into a plurality of control units or with a single control unit which executes all sub-functions are also possible in principle.

the 4 illustrates by way of example a dependency of the respective sub-functions on one another as well as a chronological processing sequence in the calculation and the necessary exchange of necessary information, for example in the form of activation signals (“activation”) or confirmations (“done”). A respective activation status (“active”/“not active”) of the sub-functions “steering function driver”, “crossfade” and “VAF” is also specified.

The process begins at the top right with an activation signal that is output to the VAF function on control unit 1, e.g. as a result of the driver pressing a button. The other sub-functions involved in the transition from manual driving to VAF are then successively activated by means of a cascade of activation signals. activated.

With a view to functional reliability, it can be advantageous if the respective sub-function sends confirming feedback ("done") to upstream sub-functions, as in 4 shown as an example. Provision can be made, for example, for such feedback to take place within a processing cycle, which can have a length in the range of 10-50 ms, for example. The VAF function is only actually activated when a (cumulative) "ready" is reported back to the VAF function by the longitudinal/lateral control.

From the 4 also shows that a message “free of momentum” is transmitted from the “steering function driver” to the longitudinal/lateral control if, in the first test phase “4.” described above, it was determined by sensors that the steering wheel 11 is torque-free. The lateral control then gives the command that the steering wheel 11 should be straightened and retracted into its ready position (cf. phase "5." in 3 ). If this was successful, the corresponding sub-function ("straighten the steering wheel and retract") of the EPS gives the feedback "steering wheel retracted", which is then passed on to the VAF function by the longitudinal/lateral control. This can be advantageous if there is a problem retracting the steering wheel 11 . In this case, the VAF function would not receive any “steering wheel retracted” feedback. Provision can then be made, for example, for the VAF not to be deactivated again until the problem with the steering wheel position has been solved.

According to some embodiment variants, however, feedback of the type “free moment” and/or “steering wheel retracted” can also be dispensed with in principle.

The following is based on the 5 a transition of the actual or perceived control of the lateral and longitudinal guidance from the driver to the ADAS 1 when changing from VAF to manual driving (or to driving with a degree of automation up to a maximum of Level 3) is described. This transition is also divided into different phases and can be fully or partially controlled by a computing device 15 of the ADAS, wherein the computing device 15 can in particular include one or more control units.

As already referred to 3 explained is also in the 5 the horizontal axis of the diagram is a time axis, the length ratios of the time sections (phases) shown not being shown to scale.

In the initial phase “6.”, the motor vehicle 3 is fully automatically controlled by the ADAS 1 in Level 4 driving mode (VAF). The steering wheel 11 and pedals 22 are in their ready position, so that the driver has maximum freedom of movement in the passenger compartment (cf. 2 ). Steering wheel 11 and pedals 12 are decoupled from the vehicle wheels or from the drive train of motor vehicle 3 in phase “6th”. The FAS 1 is fully responsible for the longitudinal and lateral guidance.

At time "7.", a deactivation of the second degree of automation (VAF) is initiated. This can be triggered, for example, by an actuation action (such as pressing a button) by the driver. In general, certain conditions must be met for the deactivation of the VAF function, such as driving within a certain speed range, within a certain acceleration band and/or within a curvature band. This is only an exemplary selection of possible deactivation conditions which are known per se and which are not the subject of the present invention and are therefore not described in greater detail at this point.

Between times "7." and "8.", the operating elements 11, 12 are automatically moved from their respective standby position (cf. 2 ) into their respective position of use (cf. 1 ) hazards.

Before the steering wheel 11 is coupled with the lateral guidance of the motor vehicle 3 (i.e. with the wheels) at time "8", the ADAS 1 synchronizes the steering wheel 11 with a current lateral guidance status of the motor vehicle 3. The steering wheel position and movement are thereby synchronized with a current wheel position or synchronized with their change.

At the latest from time “8.”, the steering wheel 11 moves synchronously with the wheels (still controlled by the fully automated lateral guidance). A virtual steering column is thus (re)created. The driver now has the opportunity to take the steering wheel 11 to take over the lateral guidance. In other words, ADAS 1 waits in phase “9.”, which follows time “8.”, for the driver to take hold of steering wheel 11 .

The driver's gripping of the steering wheel 11 is then detected by sensors by the ADAS 1, for example by checking for moments or similar variables, as already mentioned above in connection with phase "4." 3 was explained. This is one (of possibly several) prerequisite(s) for the operating elements 11, 12 to be reconnected to the longitudinal or lateral guidance and the responsibility for driving the vehicle is thus again transferred to the driver (start of phase “10.” in 5 ). Phase "9." can also be referred to as a second test phase.

Since it is not certain a priori when the driver takes hold of the steering wheel 11, phase “9” can have a variable duration, which is determined in each individual case by the point in time when the driver takes hold of the steering wheel 11. If, for example, the driver already grabs the steering wheel 11 while the steering wheel is being pulled out, phase “9” can be omitted entirely (i.e. have a length of 0 seconds).

According to one embodiment variant, it is provided that the ADAS 1 remains in the VAF driving mode and the steering wheel 11 retracts back into its ready position if the driver does not grasp the steering wheel 11 within a predetermined maximum period (e.g. 10 seconds) of phase "9." .

As mentioned, the driver has full responsibility for driving the vehicle again from the beginning of phase "10.", which can also be described as a second transitional phase.

In general, it is important (both from the transition from the second degree of automation to the first degree of automation and vice versa) that the driver is clearly clear at all times as to whether he or ADAS 1 is responsible for driving the vehicle. It is therefore preferable for the driver to help shape the respective transition between the automation wheels by means of a few unambiguous operating actions (such as pressing a button and gripping or releasing the steering wheel).

However, the transition from the VAF to the manual driver can be made easier for the driver in that the ADAS 1 initially has a Provides Level 2 function in the manner of a steering and lane guidance assistant (LSA) and controls or controls accordingly (possibly in decreasing, in particular linearly decreasing, intensity, as indicated by the ramp in 5 clarified). However, the driver can always intervene and override the level 2 function (in contrast to the VAF driving mode).

With regard to its duration, the second transitional phase "10th" can be designed, for example, similarly to the first transitional phase "3rd" described above for the transition from the first degree of automation to the second degree of automation. In this respect, reference is made to the above explanations. For example, a duration of at least 100 ms, in particular at least 200 ms, can be provided for the second transitional phase “10th”. For example, a duration in the range from 100 ms to 2000 ms can be provided for the second transition phase “10th”. It can be assumed, for example, that a second transitional phase “10th”, which lasts 100 ms or longer, in particular 200 ms or longer, can be noticed by the driver and can accordingly develop an advantageous effect.

In the present exemplary embodiment, FIG 5 a phase "11.", which is characterized by purely manual vehicle guidance by the driver. Of course, design variants are also possible in which certain functions of partially automated driving (such as LSA or ACC) are still active after the VAF has been deactivated.

the 6 illustrated - by analogy with that referred to above 4 described transition from manual driving to VAF - a possible interdependence of several sub-functions and a temporal processing sequence in the transition from VAF to manual driving, as exemplified above using the 5 was explained. The information in the 6 are insofar, and in particular against the background of the above explanations in connection with the 4 , self-explanatory.

In summary, deactivation requests and corresponding feedback are passed through the various sub-function blocks, with the "longitudinal/transverse control" function acting as the master in the present example and essentially controlling the entire process.

The Message Sequence Diagram according to 6 provides, for example, that the finished execution of the function “Fade” (which refers to the second transition phase “10.” According to 5 refers), on the one hand to the sub-function block "steering function driver" and on the other hand both to the sub-function block "steering function ADAS" and to the sub-function block "longitudinal/lateral control". If something special needs to be taken into account for the longitudinal/lateral control at this point, it can still make the appropriate adjustments. Only then does the longitudinal/lateral control send a "ready" signal to the VAF function, which is then deactivated. This chronologically last "done" signal can therefore mean that both the crossfade is completed and any necessary adjustments to the control have been made. In other words, the states of several sub-function blocks can be combined by a cascaded confirmation signal of the type “ready”.

Claims (12)

Driver assistance system (1) for a motor vehicle (3), wherein the driver assistance system supports a driving operation of the motor vehicle (3) at a first degree of automation and at a second degree of automation, wherein - the first degree of automation provides that a vehicle occupant of the motor vehicle intervenes or can intervene briefly in the longitudinal and/or lateral guidance of the motor vehicle (3) by actuating an operating element (11, 12), and - With the second degree of automation, the longitudinal and/or transverse guidance can be carried out automatically without intervention by the vehicle occupant by means of the operating element (11, 12); wherein the driver assistance system (1) is set up, - To decouple the operating element (11, 12) from the longitudinal and/or transverse guidance when the motor vehicle (3) is operated at the second degree of automation; and - during a transition from the first degree of automation to the second degree of automation during a first transition phase, in which the operating element (11, 12) is already decoupled from the longitudinal and/or transverse guidance, a haptic feedback by means of the operating element (11, 12). produce, which gives the vehicle occupant the feeling of still being able to act on the longitudinal and/or transverse guidance by means of the operating element (11, 12). Driver assistance system (1) after claim 1 , with the haptic feedback decreasing in intensity over time during the first transition phase. Driver assistance system (1) according to any one of the preceding claims, wherein the operating element (11, 12) comprises at least one element from the following list: - a steering wheel (11); - a joystick; - a pedal (22). Driver assistance system (1) according to any one of the preceding claims, comprising a mechanism which is set up to automatically transfer the operating element (11, 12) from a use position to a ready position during the transition from the first degree of automation to the second degree of automation, in order to enable the vehicle occupant to have the vehicle occupant activated second degree of automation to offer more comfort and/or freedom of movement. Driver assistance system (1) after claim 4 , wherein the driver assistance system (1) is set up to check whether the vehicle occupant acts on the operating element (11, 12) and to initiate the transfer of the operating element (11, 12) into the ready position only under the condition that the vehicle occupant does not act on the Operating element (11, 12) acts. Driver assistance system (1) after claim 4 or 5 , wherein the mechanism is further set up to automatically transfer the operating element (11, 12) from the ready position to the use position when there is a transition from the second degree of automation to the first degree of automation. Driver assistance system (1) according to one of the preceding claims, wherein the driver assistance system (1) is set up, the operating element (11, 12) in a transition from the second degree of automation to the first degree of automation initially with a current longitudinal and / or lateral guidance state of the motor vehicle ( 3) to synchronize before the operating element (11, 12) is coupled to the longitudinal and/or transverse guide of the motor vehicle (3). Method for operating a driver assistance system (1), comprising transferring a driving operation of the motor vehicle (3) from a first degree of automation, in which it is provided that a vehicle occupant of the motor vehicle (3) moves into the longitudinal and/or lateral guidance of the motor vehicle (3) intervenes or can intervene briefly, to a second degree of automation, in which the longitudinal and/or lateral guidance can be carried out automatically without intervention by the vehicle occupant by means of the operating element (11, 12) and the operating element (11, 12) is decoupled from the longitudinal and / or transverse guide, wherein during a first transitional phase, in which the control element (11, 12) is already decoupled from the longitudinal and/or transverse guide, the control element (11, 12) generates haptic feedback, which gives the vehicle occupant the feeling of being still using the control element (11, 12) to be able to act on the longitudinal and/or transverse guidance. procedure after claim 8 , wherein the operating element (11, 12) is automatically transferred from a position of use to a standby position during the transition from the first degree of automation to the second degree of automation in order to offer the vehicle occupant more comfort and/or freedom of movement when the second degree of automation is activated. procedure after claim 9 , wherein it is checked whether the vehicle occupant acts on the operating element (11, 12), and wherein the transfer of the operating element (11, 12) into the ready position is initiated only under the condition that the vehicle occupant does not act on the operating element (11, 12 ) acts. procedure after claim 9 or 10 , further comprising transferring the driving operation from the second degree of automation to the first degree of automation, wherein the operating element (11, 12) is automatically transferred from the ready position to the use position when changing from the second degree of automation to the first degree of automation. Method according to one of the preceding claims, wherein the operating element (11, 12) is initially synchronized with a current longitudinal and/or lateral guidance state of the motor vehicle (3) during the transition from the second degree of automation to the first degree of automation, before the operating element (11, 12 ) is coupled to the longitudinal and/or transverse guidance of the motor vehicle (3).

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