Abstract:
A driver assistance device in a motor vehicle can completely or partially independently guide the motor vehicle. The driver assistance device has an operating device having a grip element which is arranged on a center console of the motor vehicle and on which a plurality of operating elements are arranged. To improve clarity, the grip element can be moved with respect to an interior trim of the motor vehicle by an actuator of the operating device. A control device of the driver assistance device is designed to adjust a position of the grip element with respect to the interior trim by controlling the actuator on the basis of the currently active assistance mode.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application is based on and hereby claims priority to International Application No. PCT/EP2012/004816 filed on Nov. 21, 2012 and German Application No. 10 2010 002 307.3 filed on Feb. 6, 2012, the contents of which are hereby incorporated by reference. 
     BACKGROUND 
     The invention relates to a motor vehicle and method for operating a motor vehicle having a driver assistance device which is designed to independently guide the motor vehicle during travel of the motor vehicle and in this case can be changed over between at least two assistance modes which differ from one another in terms of a degree of independence of the driver assistance device when guiding the motor vehicle. 
     The term “guiding the motor vehicle” comprises here, on the one hand, the steering of the motor vehicle (following the course of a road, orienting the motor vehicle within a lane, lane-changing maneuver), which is also referred to as lateral guidance, and, on the other hand, the control of the speed of the motor vehicle (accelerating, braking, emergency braking, maintaining the speed), which is also referred to as longitudinal guidance. 
     A driver assistance system of the specified type is known from DE 10 2010 022 433 A1. According to said document, a driver assistance system can, in a fully automatic assistance mode, guide the vehicle completely independently. The driver of the motor vehicle then has to operate neither the steering wheel nor the pedals of the motor vehicle during travel and can therefore turn his attention to other things, for example the operation of an infotainment system, for a relatively long period. 
     However, independent guidance of the motor vehicle can also be understood as meaning a semi-automatic assistance mode in which the degree of independence of the driver assistance system is reduced when guiding the motor vehicle and which can then include, for example, merely of the functionality of adjusting the speed of the motor vehicle to a desired or set speed which is predefined by the driver by setting a value of the corresponding driving parameter of the driver assistance system (cruise control). 
     A further desirable assistance mode is the autonomous guidance of the motor vehicle by a driver assistance device. In contrast to the fully automatic assistance mode, in the autonomous assistance mode the driver assistance device also decides which values are to be implemented for the driving parameters (desired distances, desired speed) for a currently implemented driving maneuver and/or which driving maneuvers (lane change, turning off the road, parking and the like) are to be implemented. In contrast, in the fully automatic assistance mode, provision is made for the driver to use a user interface to predefine which driving maneuvers are to be implemented or which distances and speeds are to be adjusted by the driver assistance device during a currently implemented driving maneuver when traveling along a lane. Another difference between the two assistance modes can relate to how the driver assistance device reacts in the event of an unforeseen development of events on the road, that is to say if safe guidance is no longer ensured by the driver assistance device. In the fully automatic assistance mode, provision is then made for the driver assistance device to be deactivated and to transfer control of the motor vehicle to the driver, while, in contrast, in the autonomous assistance mode, the driver assistance device itself places the motor vehicle in a safe state, for example by stopping the motor vehicle. 
     Depending on the currently active assistance mode, certain guidance tasks are carried out independently by the motor vehicle, i.e. without involvement of the driver, during travel. However, in this case, it must be ensured, for each assistance mode in which the driver assistance device can be operated, that the driver is always clear as to the degree to which the driver assistance system monitors and guides the motor vehicle, which intervention possibilities are still available to the driver himself during the guidance of the motor vehicle and which guidance tasks the driver must necessarily carry out himself. If the driver loses an overview here, his safety may be compromised. If the driver wrongly believes, for example, that the driver assistance device is in the fully automatic assistance mode and therefore lets go of the steering wheel in order to deal with the infotainment system, the vehicle may run off the road in this case because the driver assistance device is, for example, not activated at all, that is to say a fully manual driving mode is demanded of the driver (this is therefore referred to as the manual assistance mode here). 
     The range of independence of the driver assistance device (automation range) which extends from manual driving to partial and full automation and then on to autonomy should in its complexity in future be transparent and comprehensible to the user in terms of operating it. Important properties of future operating concepts are a manageable complexity of these four specified assistance modes, clear delimitability between the individual assistance modes and characteristic operating modalities within the individual assistance modes. Whereas established operating elements such as buttons, a steering wheel or a lever are available for partial automation (for example cruise control, active lane control, i.e. lane-keeping assistance), until now there have only been conceptual approaches to the prototypical operation of full automation and autonomy. These approaches are frequently merely supplements or extensions of existing operating concepts and constitute isolated solutions. Such isolated solutions generally do not amount to anything more than mere functional integration into existing operating elements, which leads to an increase in the functional density of the individual operating elements and therefore is not targeted owing to the variety and complexity of the operating devices which result therefrom. The manageability and functional variety of current operating elements have already been fully exploited. 
     SUMMARY 
     One potential object is to ensure clarity when operating a driver assistance device in a motor vehicle having a driver assistance device which can guide the motor vehicle completely or partially independently. 
     The inventors propose a driver assistance device has a grip element, that is to say a lever for example, which is arranged in a primary gripping area for a driver of the motor vehicle and on which a plurality of operating elements of the driver assistance device are arranged. In this case, a primary gripping area should be generally understood as meaning that region of the motor vehicle which can be reached by the driver with a hand from the driver&#39;s seat in a relaxed, reclined posture, that is to say the center console or the driver&#39;s door of the motor vehicle, for instance. A driver can be guided by the grip element when guiding the motor vehicle if he wishes to know which assistance mode the driver assistance device is currently in. For this purpose, the grip element can be moved with respect to the interior trim of the motor vehicle, that is to say a housing of the center console or a trim of the side door, by an actuator of the operating device. A control device of the driver assistance device is designed to actively adjust a position of the grip element with respect to interior trim by controlling the actuator, in which case the improved orientation of the driver when operating the driver assistance device precisely results, in accordance with a method proposed by the inventors, from the fact that the position of the grip element is adjusted by the control device using the actuators on the basis of which assistance mode is currently active. Adjusting the position changes the relative position of the grip element with respect to the driver, with the result that the driver must simply only place a hand on the grip element in order to become clear as to which assistance mode the driver assistance device is currently in and which operating possibilities the driver actually has. For example, if the grip element is in the position which indicates the fully automatic assistance mode, the driver intuitively knows that he now no longer actively needs to steer the vehicle and must control the driving behavior of the motor vehicle only using the grip element. He can therefore let go of the steering wheel in this case and also need not be startled if the vehicle no longer reacts to operation of the steering wheel. 
     The concept of an actively adjustable grip element with operating elements integrated therein has the advantage that the operation of the automation range (manual driving, semi-automatic and fully automatic assistance mode and autonomous assistance mode) provides orientation using the single grip element: the position of the grip element and the operating properties of the individual operating elements can be adapted in a variable manner and on the basis of the currently selected assistance mode. 
     One advantageous embodiment of the motor vehicle provides for the grip element to have at least one of the operating elements on one of its end faces which faces a driver&#39;s seat of the motor vehicle. This is preferably a pushbutton switch which may be in the form of a rocker, for example. If the driver grips around the grip element, he can very easily actuate this operating element with his thumb. In this case, in at least one of the assistance modes, the operating element is operated in such a manner that it can be used to set a driving parameter of the driver assistance system on which the guidance behavior of the driver assistance device is dependent. For example, provision may be made for the desired or set speed for cruise control to be set in the semi-automatic assistance mode using the operating element. This embodiment of the motor vehicle has the advantage that, by changing the position of the grip element, the operating element can only be easily gripped by the driver, that is to say is presented to the latter, when the grip element is also in the position belonging to the semi-automatic assistance mode. In another assistance mode in which the operating element does not have a function, the operating element can then be pivoted out of the primary gripping range of the driver, which gripping range can be easily reached by the driver during travel and without diverting his gaze from the traffic. The situation in which the driver inadvertently attempts to carry out an operating action on the operating element in the incorrect assistance mode is then avoided. 
     In order to change between two assistance modes, the grip element expediently has an operating element on a side which can be reached by the user of the operating device at least in a predominant number of possible positions of the grip element. For example, a button may be provided here on a top side of the grip element. The driver can therefore advantageously reach for the grip element without diverting his gaze from the traffic, can discern the currently active assistance mode from the position of the grip element and can then immediately activate the “next higher” assistance mode, that is to say can increase the degree of independence of the driver assistance device, by operating the operating element. A sensor button which can be used to reliably distinguish between whether the driver has only placed his hand on the grip element or actually wishes to actuate the sensor button has proved to be particularly favorable here. At the same time, this also forces a position of the hand when operating the sensor (perpendicular tapping of the button), in which position the situation in which the hand gets caught during automatic movement of the operating device is avoided. Suitable sensor buttons are based on a capacitive sensor or an infrared sensor, for example. 
     It has proved to be particularly advantageous if not only the individual operating elements but also the grip element itself are used to operate the driver assistance device. For this purpose, the grip element can be operated as a control lever in at least one assistance mode, which control lever can be deflected in a monostable manner by rotational deflection (for example tilting) and/or rotation and/or translatory deflection in a manner transverse to a vertical axis of the motor vehicle. In other words, the grip element can be used as a type of “joystick” here. In this case, the deflection is then carried out with respect to that position into which the grip element was originally brought by the control device in the respective assistance mode. Indirect guidance of the motor vehicle by the grip element is expedient, in particular in connection with a fully automatic assistance mode. Intuitive operation of the user interface (already described) in order to trigger driving maneuvers can be enabled using a control lever. 
     A force-displacement characteristic curve is expediently set during operation of the grip element as a control lever by at least one actuator of the operating device on the grip element. Such a characteristic curve makes it possible to oppose the user of the operating device with a predetermined counterforce on the basis of a deflection of the grip element. This makes it possible to then transmit an item of information to the user in a haptic manner by a force decrease or a force increase, for example a particularly favorable speed or distance setting or a risk of guiding the vehicle too close to the curb, which risk is associated with increasing deflection of the grip element. 
     It has likewise proved to be expedient to produce force feedback for the operator of the operating device by at least one actuator on the grip element. Unlike in the case of a force-displacement characteristic curve, the control lever can then additionally be deflected in another direction counter to the force of the operator&#39;s hand. This makes it possible to give the operator an impression of the actual road conditions or else an operating recommendation. Parameters from an environment sensing system (image processing on the basis of a camera or a radar) may likewise be communicated to the user. 
     Since the position of the grip element is changed when changing between two assistance modes, it must be ensured in this case that the operator&#39;s hand does not get caught between the grip element and the housing of the center console or the side trim. This is preferably achieved by virtue of the fact that a deactivation button is provided in the primary gripping area at a distance from the grip element, and the driver assistance device is designed to deactivate the currently active assistance mode when the deactivation button is actuated. When the deactivation button is actuated by the operator, it is therefore ensured that the operator&#39;s hand is on the deactivation button and is not in the region of the grip element. 
     In the motor vehicle, the driver assistance device can be used in a very flexible manner to operate a multiplicity of different assistance modes. One embodiment of the motor vehicle therefore provides for the driver assistance device to be designed to guide the motor vehicle in a semi-automatic manner in a semi-automatic assistance mode on the basis of driving parameters which can be set by a driver using the operating device. In this case, however, by maintaining corresponding mechanical or electromechanical coupling, it is possible for the driver to directly intervene in the guidance of the motor vehicle using a steering handle, that is to say a steering wheel for instance, and/or a pedal. Semi-automatic guidance by the driver assistance system should be understood as meaning, in particular, that the driver assistance device sets the speed and complies with a distance between the motor vehicle and a vehicle traveling in front. 
     As already mentioned, it is also possible to implement an embodiment of the motor vehicle in which the driver assistance device is designed to guide the motor vehicle in a fully automatic manner in a fully automatic assistance mode by independent lateral and longitudinal guidance and in this case to receive a selection of a driving maneuver to be implemented by the driver assistance device and/or to receive a value for a driving parameter of a currently implemented driving maneuver from the driver via a user interface. In this case, it is then particularly appropriate to operate the grip element as a control lever in order to trigger the driving maneuvers or set the driving parameters. The user interface may be, for example, that interface which was filed as German Application No. 10 2012 002 304.9 filed on Feb. 6, 2012 by the applicant together with the present application on the same date. 
     In the motor vehicle, provision may even be made for the driver assistance device to be designed to autonomously guide the motor vehicle in an autonomous assistance mode the motor vehicle in an autonomous assistance mode in a fully automatic manner by independent lateral and longitudinal guidance and in this case to also independently determine a driving parameter value for a driving parameter of a currently implemented driving maneuver and/or to independently select a driving maneuver to be implemented. 
     In connection with the autonomous assistance mode or the manual assistance mode in which no intervention in the vehicle guidance by the driver assistance device is provided, an advantageous development of the motor vehicle results if the control device is set up to bring the grip element into bearing contact with the housing of the center console or the trim or to countersink the grip element therein in at least one of these assistance modes. This then makes it impossible for a user of the operating device to grip around the grip element. If the user therefore attempts to grip around the grip element in order to actuate one of its operating elements or to use the grip element as a control lever, the user is prevented from doing so by the position of the grip element and is reminded that he is currently not able to operate the driver assistance device. 
     Although the position into which the grip element is moved by the control device when a corresponding assistance mode is switched on is predetermined, it can be determined in any desired manner by a user, for example during production of the motor vehicle or during configuration. Provision is preferably made for the grip element to be moved, in the vehicle longitudinal direction, with an increasing degree of independence of the driver assistance device, into a position which is further away from the steering wheel. Four assistance modes are provided in a very particularly preferred embodiment, namely a manual assistance mode in which no guidance at all by the driver assistance apparatus is provided, a semi-automatic assistance mode in which at least cruise control is provided, a fully automatic assistance mode in which at least independent lateral guidance is provided, and an autonomous assistance mode in which completely independent guidance of the motor vehicle by the driver assistance device without the possibility of intervention by the driver is provided. As this sequence of assistance modes is run through by corresponding changeover, the grip element is gradually moved in this case from the front (manual driving) on the center console to a position further to the rear with each changeover operation until it finally comes into bearing contact with a rear wall of the housing of the center console in the autonomous assistance mode. 
     In connection with the proposed method, it also may include developments and features which have already been described in connection with the motor vehicle. Therefore, these developments of the method are not explained again here. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       These and other objects and advantages of the present invention will become more apparent and more readily appreciated from the following description of the preferred embodiments, taken in conjunction with the accompanying drawings of which: 
         FIG. 1  shows a schematic illustration of a center console of a potential embodiment of the proposed motor vehicle, in a perspective view, 
         FIG. 2  shows a schematic illustration of a movement sequence of a grip element on the center console from  FIG. 1  in a perspective view; and 
         FIG. 3  is a flow chart showing one potential embodiment for the proposed method. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Reference will now be made in detail to the preferred embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to like elements throughout. 
       FIG. 1  shows a center console  10  of a motor vehicle which is not illustrated any further. The motor vehicle may be, for example, an electrically driven automobile or an automobile driven with an internal combustion engine. The center console  10  is situated beside a driver&#39;s seat  14 , as seen in the forward direction of travel  12  of the motor vehicle. A recess  16  is formed in the center console  10 , in which recess a grip element  18  is supported by a support element  20 , for example a metal limb. In the example shown in  FIG. 1 , the grip element  18  has a basic shape of a cuboid with rounded corners and edges, similar to an ingot or a glasses case. It may be, for example, a hollow body which is produced using injection molding technology and may be covered with artificial leather. The grip element  18  is mechanically coupled, via the support element  20 , to an actuator (not illustrated), for instance an electric motor, which is inside a casing or a housing  22  of the center console  10 . A control unit (not illustrated) can change a position of the grip element  18  inside the recess  16  by the actuator.  FIG. 2  illustrates, in a superimposed illustration, which four predetermined positions P 1 , P 2 , P 3 , P 4  can be assumed by the grip element  18  within the recess  14 . The control unit may be a microcontroller, for example. 
     In the positions P 2  and P 3 , the grip element  18  forms a lever, around which a driver sitting on the driver&#39;s seat  14  can grip and which can be used by the driver to exert a force on sensors inside the housing  22  via the support element  20 . This lever embodies an integrative approach which simplifies the operation of an automation range of a driver assistance device of the motor vehicle for the driver. When the driver assistance system is activated, partial automation and full automation all the way to autonomy when guiding the motor vehicle by the driver assistance system can be enabled on the basis of an assistance mode. In this case, the grip element  18  and the support element  20  provide a single operating part in the form of a lever, the position of the grip element  18  and the operating properties of individual operating elements arranged thereon being variable and being able to be set on the basis of the currently active assistance mode. 
     The established operating elements are therefore used for manual driving, that is to say the steering wheel and the pedals are directly coupled to the steering system of the motor vehicle or to the engine. In this manual assistance mode of the driver assistance device, the grip element  18  is flush with a front wall  26  of the recess  16 , as seen in the direction of travel  12  (position P 1 ). It is then not possible to clasp the grip element  18 . After a sensor button  28  has been actuated, the grip element  18  is moved from its flush position into the position P 2  by the actuator in the center console  10 . A semi-automatic assistance mode in the driver assistance device is likewise activated by pressing the sensor button  28 . The sensor button  28  may be a capacitive button, for example. The button  28  is situated on a top side  30  of the grip element  18 , which top side can be easily reached by the driver in all four positions P 1  to P 4 . A touch surface of the button  28  is preferably smaller than the surface of the side  30 , with the result that a driver does not unintentionally actuate the button  28  when gripping around the grip element  18 . 
     Instead of only bringing the grip element  18  into bearing contact with the wall  26  in the manual assistance mode, provision may also be made for a shaft to be provided in the housing  22 , in which the grip element  18  can be countersunk. In this case, it should then be ensured that the sensor button  28  remains reachable in order to be able to activate the next higher assistance mode (that is to say the semi-automatic assistance mode in this case). The sensor button  28  is activated only if the driver assistance device detects that the vehicle can be independently guided by the driver assistance device in the semi-automatic assistance mode. 
     As soon as the grip element  18  reaches the position P 2 , the driver discerns from its position P 2  that the driver assistance device is in the semi-automatic assistance mode. In this case, the driver assistance device is then first of all in the stand-by mode, that is to say does not yet intervene in the guidance of the motor vehicle, but can be activated by the driver by pressing a SET button  32 . The SET button  32  is part of a button area  34  on an end face  24  of the grip element  18  facing the driver. The button area  34  also comprises an operating element  36  for adjusting the speed, which operating element is used to change the set speed in the semi-automatic assistance mode. The operating element  36  may be in the form of a rotary knob, a monostable rocker or a rocker button, for example. The semi-automatic assistance mode can be deactivated again by actuating an operating element  38  which is installed in the center console in the area surrounding the grip element  18 . The operating element  38  may be a deactivation button, for example. Actuating the deactivation button  38  outside the gripping and movement region for the grip element  18  means that there is no risk of crushing. 
     In the case of the deactivation button  38 , provision may be made for the semi-automatic assistance mode to be retained and to only be changed to the stand-by mode by pressing the button for a relatively short time, whereas the semi-automatic assistance mode is deactivated and is changed to the manual assistance mode again by pressing the deactivation button  38  for a long time (so-called “long push”). 
     In the semi-automatic assistance mode (position P 2  of the grip element  18 ), a desired distance of a longitudinal control system of the driver assistance system can also be effected by longitudinally shifting the grip element  18  along the direction of travel  12 . In this case, the desired distance forms a driving parameter of the driver assistance device. For this purpose, the grip element  18  is mounted in a monostable manner in the position P 2 , that is to say it moves by itself back into this position P 2  again when it is released. In order to set the desired distance, the grip element  18  is kept deflected from the position P 2  until an indication and/or the actual desired distance is/are at the desired level. 
     In the semi-automatic assistance mode, it is also possible for the driver to intervene in the longitudinal guidance and thus to change the speed by actuating the gas pedal or the brake pedal. By briefly deflecting the grip element  18  in the longitudinal direction  12  of the vehicle, the driver can then again cause the driver assistance system to adjust the speed of the motor vehicle to the set speed (so-called resume function). The described deflections of the grip element  18  along the direction of travel  12  have proved to be particularly useful from an ergonomic point of view. However, in connection with another refinement of the vehicle interior, it may also be expedient to alternatively or additionally allow a movement to the rear, that is to say contrary to the direction of travel  12 , or else in a manner transverse to the direction of travel as a further actuating action. 
     The next higher automation level, in which the driver assistance system can guide the motor vehicle, can be activated via the sensor button  28  on the top side  30  of the grip element  18  and/or via a manual adjustment by the user. In this case, the grip element  18  is brought into the position P 3 . In this fully automatic assistance mode which has then been set, the actuating elements of the button area  34  do not have a function, apart from the sensor button  28  and the deactivation button  38 . A parameter and maneuvering interface for operating the driver assistance system in the fully automatic assistance mode is implemented by manual deflectability of the lever in an X-Y plane perpendicular to the vehicle vertical axis  40 . In this case, the parameter and maneuvering interface may additionally comprise a screen which displays, to the driver, the desired distance from a vehicle traveling in front which the driver assistance device is attempting to adjust and the lateral position which is intended to be assumed by the motor vehicle in the lane currently being traveled on. The desired distance and the lateral position as well as a desired speed (if no vehicle is traveling in front) form driving parameters in the fully automatic assistance mode. By virtue of the fact that the driver now exerts a force on the support element  20  at the grip element  18  along the direction of travel  12  or transversely with respect to the latter, the sensors on the support element  20  detect these actuating actions and the desired values are accordingly set in the fully automatic assistance mode. In the position P 3  of full automation, the grip element  18  can be conveniently reached without a large amount of movement by the driver who is sitting in a relaxed manner and no longer needs to actuate the steering wheel. If the driver uses the grip element  18  as a hand rest, he can be additionally informed at any time of the current desired values for the controlled guidance of the motor vehicle by the driver assistance system by force feedback from the parameter and maneuvering interface, which feedback is produced using the actuators in the center console  10 . In this case, the position P 3  of the grip element  18  is then dependent both on the currently active assistance mode (fully automatic assistance mode) and on the desired values which are presented to the driver using the force feedback. 
     The function of a starting trigger can additionally be achieved using the grip element  18 . As a result, after the motor vehicle has been automatically braked by the driver assistance system and before automatic restarting, it is then possible to obtain confirmation from the driver that he is prepared for the restarting. The SET button  32 , for example, can be used as a starting trigger. A potential trigger can also be achieved using the grip element  18 . Such a trigger is described, for example, in the document DE 10 2010 022 433 A1 which has already been mentioned. 
     In connection with the operation of the parameter and maneuvering interface mentioned, provision can also be made for the driver&#39;s hand on the grip element  18  to be opposed with a force which is produced by one of the actuators in the center console  10 . This makes it possible to signal to the driver during deflection of the grip element  18 , by a force-displacement characteristic curve, where particularly favorable or unfavorable values result for the driving parameters to be set. It is therefore possible to signal to the driver, for example, that the distance from the vehicle traveling in front, which has been set by him, is becoming too short by making it difficult for the driver to deflect the grip element  18  further in the direction of travel  12 . Force decreases in the force-displacement profile make it possible to indicate a favorable value in a tactile manner. 
     The driver assistance system of the motor vehicle is additionally able to autonomously guide the motor vehicle. In this case, the driver assistance system itself then decides which distance from the vehicle traveling in front and which lateral position should be assumed by the motor vehicle in a lane. The driver assistance system may then similarly independently start and carry out an overtaking maneuver, a turning-off maneuver, a parking maneuver and the like. The autonomous assistance mode of the driver assistance system can be activated in this case only when the driver assistance system detects that the vehicle can be changed to a safe state at any time even without involvement of the driver, that is to say the vehicle can be brought to a standstill, for example. Such an autonomous mode is conceivable, for example, in a traffic jam situation if the motor vehicle can be guided only at walking speed. 
     If the autonomous mode is appropriate for activation under given switch-on conditions, it can be activated by the driver by actuating the sensor button  28  on the surface  30  of the lever. Besides the autonomous assistance mode, no actuation of the grip element  18  and the buttons of the button area  34  which are situated thereon is provided in a manner similar to the position P 1  of manual driving. Only manual deactivation using the deactivation button  38  must be ensured. Therefore, in the autonomous assistance mode, the grip element  18  is again moved into a flush position with a wall  42  of the recess  14 . This position P 4  of the grip element  18  in the autonomous assistance mode differs from the position P 1  in the manual assistance mode in a manner clearly discernible to the driver. 
     If the autonomous assistance mode is deactivated again by actuating the deactivation button  38 , the grip element  18  automatically moves into a fallback position, for example into the position P 2 , where the stand-by mode of the semi-automatic assistance mode can then be activated. 
     The following table again summarizes the operating possibilities which are provided to the driver via the grip element  18  and the deactivation button  38  on the basis of the different assistance modes by virtue of functionalities of the driver assistance system being respectively assigned to the individual operating elements. 
     
       
         
               
               
               
             
               
             
               
               
               
             
               
             
               
               
               
             
               
             
               
               
               
             
               
             
               
               
               
             
           
               
                   
               
               
                 Function 
                 Operation 
                 Explanation 
               
               
                   
               
             
             
               
                   
               
             
          
           
               
                 Manual driving (P1) 
               
             
          
           
               
                 Change to partial 
                 Button 28 
                 Lever is moved 
               
               
                 automation 
                   
                   
               
             
          
           
               
                 Partial automation (P2) 
               
             
          
           
               
                 Stand-by mode 
                 Button 38 
                 Button on center 
               
               
                   
                   
                 console 
               
               
                 SET 
                 Button 32 
                   
               
               
                 Speed setting 
                 Button 36 
                   
               
               
                 Setting the desired  
                 Tap the grip 
                 Direction of travel 
               
               
                 time gap 
                 element in ±x for  
                 12 corresponds to 
               
               
                   
                 a long time 
                 the −x direction 
               
               
                 Resume and starting 
                 Tap the grip 
                   
               
               
                 trigger 
                 element 18 in ±x 
                   
               
               
                   
                 for a short time 
                   
               
               
                 Change to full 
                 Button 28 
                 Sensor button 
               
               
                 automation 
                   
                   
               
               
                 OFF 
                 Button 38 (tap for 
                 Button on center 
               
               
                   
                 a long time) 
                 console 
               
             
          
           
               
                 Full automation (P3) 
               
             
          
           
               
                 Starting trigger 
                 Button 32 
                   
               
               
                 Potential trigger 
                   
                   
               
               
                 Maneuvering 
                 Shift grip element 
                 Monostable 
               
               
                 interface 
                 in the X-Y plane 
                 deflection 
               
               
                   
                   
                 perpendicular to 
               
               
                   
                   
                 the vehicle 
               
               
                   
                   
                 vertical axis 
               
               
                 Change to autonomy 
                 Button 28 
                 Sensor button 
               
               
                 Deactivation of 
                 Button 38 
                 Button on center 
               
               
                 full automation 
                   
                 console 
               
             
          
           
               
                 Autonomy (P4) 
               
             
          
           
               
                 Deactivation of 
                 Button 38 
                 Button on center 
               
               
                 autonomy 
                   
                 console 
               
               
                   
               
             
          
         
       
     
     The examples show how the indicator effect of the grip element (positions P 1  to P 4 ) on the basis of the different degrees of independence of the assistance modes of the driver assistance system and the mode-dependent operating possibilities of the grip element  18  and its operating elements provide a highly system-specific representation and operability of the driver assistance device in the respective assistance modes. This increases the system transparency and simplifies the learnability of the automation range for the driver. The described active feedback from the grip element  18  in the fully automatic assistance mode can additionally make it possible to communicate the state of the “vehicle controlled system” (that is to say the presentation of the desired values of the driving parameters which define the guidance behavior of the driver assistance device) to the driver even while operating an infotainment system, for example. The position of the actuating part, which is variable in the direction of travel  12  on the basis of the currently active assistance mode, also makes it possible to position the operating elements in relation to the steering wheel in a manner which is optimal for operation by a driver for the semi-automatic and fully automatic assistance mode. It is therefore possible to grip around the grip element in these assistance modes without any problems and to achieve a comfortable sitting position with good ability to reach the grip element  18  in the motor vehicle. 
     The invention has been described in detail with particular reference to preferred embodiments thereof and examples, but it will be understood that variations and modifications can be effected within the spirit and scope of the invention covered by the claims which may include the phrase “at least one of A, B and C” as an alternative expression that means one or more of A, B and C may be used, contrary to the holding in  Superguide  v.  DIRECTV , 69 USPQ2d 1865 (Fed. Cir. 2004).