Abstract:
A device for approving automatic guidance of a vehicle, having an interface to a monitoring apparatus for at least partially monitoring a vehicle driver located in the vehicle, having an interface to an apparatus for automatically guiding the vehicle and for ascertaining a travel direction of the vehicle when automatic guidance is to be performed, and having an analysis unit for comparing a field of vision of the driver, which is determined from the monitoring of the driver, to the travel direction of the vehicle during the automatic guidance, automatic guidance only being approved if the travel direction of the vehicle during the automatic guidance is in the field of vision of the driver.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention is directed to a device and a method for approving automatic guidance of a vehicle. 
     2. Description of Related Art 
     A method for warning a driver of a vehicle is already known from published German patent document DE 100 39 795 A1, in which warnings are output as a function of an attentiveness of the driver. For this purpose, the viewing direction of the driver is associated with a high attentiveness and the remaining directions are associated with a low attentiveness. 
     An automatic parking device for vehicles is known from published German patent document DE 38 13 083 A1, which has movement sensors for measuring a movement route of the automobile, obstruction sensors for ascertaining a position of obstructions around the automobile, and a microcomputer, which produces an output signal to control a control mechanism, a gearshift unit, and a brake system of the motor vehicle, in order to park the vehicle automatically. 
     SUMMARY OF THE INVENTION 
     The device according to the present invention for approving automatic guidance of a vehicle has the advantage over the related art that automatic guidance of the vehicle is only approved if it is ensured that the field of vision of the driver may detect at least the driving path of the vehicle in the direction in which the vehicle is automatically guided. The field of vision is to refer to the entire spatial area which may be detected by an observer without an eye movement. 
     It is therefore ensured that the optical sensory channels of the driver detect a driving path in addition to the sensors of the vehicle and it is thus ensured that the driver, who is eventually responsible for the driving actions of the vehicle, actually monitors the travel of the vehicle. If the driver discovers an obstruction in the driving path of the vehicle, he will perceive this obstruction, since the vehicle only performs automatic guidance of the vehicle when the driving path is in the field of vision of the driver. However, if the driver perceives the obstruction, he may react himself and terminate automatic guidance of the vehicle, for example, by initiating a braking action himself. 
     The present invention therefore prevents the driver with the aid of an automatic driver support from being enticed to no longer observe the driving path of the vehicle during automatic travel. In particular for the case in which obstructions move into the driving path provided for the automatic driving or in which an obstruction detection is incorrect, for example because of a poor detectability of an obstruction, possible damage to the vehicle or to the obstruction may therefore be prevented using the visual detection by the driver as an additional protection measure. Accordingly, it is also possible to reduce redundancy requirements on obstruction detection systems for monitoring the vehicle surroundings and thus the costs for such obstruction detection systems, since the involvement of the driver as an additional monitoring entity may be ensured. For not only may the system for automatic guidance of the vehicle decelerate the vehicle in the event of a detected obstruction, but also the driver himself may perform a deceleration if needed because it is ensured he monitors the driving path of the vehicle. Through the additional monitoring by the driver, error tolerances may additionally be selected as smaller, so that an occurrence of automatic terminations of the automatic driving, which could occur as a result of high safety tolerances, may be reduced. 
     Accordingly, a method according to the present invention is advantageous in which automatic guidance is only approved if the travel direction of the vehicle during the automatic guidance is in a field of vision of the driver. 
     Advantageous refinements and improvements of the device specified in the independent claim and the method specified in the independent claim are possible through the measures listed in the dependent claims. The field of vision may thus be detected easily by analysis of the viewing direction and/or the head position of the driver. 
     Furthermore, it is advantageous according to the present invention that a corresponding approval of automatic driving is used for the case in which the vehicle is automatically guided into a parking space in reverse. In particular, when driving into a parking space, various error sources may be eliminated with the aid of the additional monitoring by the driver. Thus, for example, the vehicle may be braked by the driver if a parking space measurement is performed imprecisely or incorrectly. Furthermore, it is also possible that the driver may react to moving parking space boundaries or obstructions moving into the parking space. In addition, it may advantageously be ensured that a parking procedure may be performed as continuously as possible and without unnecessary termination. Nonetheless, in particular smaller or hard to detect obstructions, such as a small pet, may be reliably detected by a driver and the vehicle may be stopped accordingly. 
     Furthermore, it is advantageous to provide a camera system for ascertaining a viewing direction or a head position of the vehicle driver, since corresponding detection devices are possibly already present in the vehicle for other purposes for driver monitoring. In addition, the corresponding viewing direction is easily detectable with the aid of an appropriate camera system. In this case, the camera is advantageously situated on a vehicle roof or alternatively on a dashboard of the vehicle. Through this positioning, the driver may be observed without being obstructed in his vision by the camera system. 
     Furthermore, it is advantageous that for the case in which the driver no longer looks in the appropriate travel direction of the vehicle, automatic guidance is terminated. It may therefore be ensured that the vehicle is only moved automatically in a direction as long as monitoring is ensured by a look of the driver in the appropriate travel direction. For this purpose, it is additionally advantageous to decelerate the vehicle, possibly to a standstill, for the case in which the driver no longer has an appropriate travel direction in his field of vision. In this way, a movement of the vehicle which is no longer monitored by the driver may be prevented during automatic guidance of the vehicle. The driver is advantageously warned before an automatic deceleration, in order to notify the driver of a carried out or imminent termination of the automatic guidance. The driver may either turn his field of vision back to the travel direction of the vehicle, in order to continue the automatic guidance of the vehicle, or may take over the control of the vehicle himself again. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Exemplary embodiments of the present invention are shown in the drawings and are explained in greater detail in the following description. 
         FIG. 1  schematically shows a top view of a vehicle having a device according to the present invention for approving automatic guidance of a vehicle. 
         FIG. 2  shows a view of a vehicle having a device according to the present invention for approving automatic guidance of the vehicle in a side view. 
         FIG. 3  shows a relevant vehicle in a top view. 
         FIG. 4  shows an exemplary embodiment for carrying out a method according to the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     The device according to the present invention for approving automatic guidance of a vehicle may be used for any desired vehicles and for any desired driving maneuvers. However, automatic guidance of a vehicle is advantageous in particular in those cases in which a computerized control of the vehicle sometimes has an advantage over a manual control of the vehicle by an average driver. This is the case in particular for parking procedures, in particular for parking procedures parallel to a travel direction of the vehicle, during which a driver may often assess a parking space by sight only very poorly and sometimes there is a very small tolerance range in the guidance of the vehicle for steering the vehicle into a desired parking space using as few passes as possible. In addition, the relatively low vehicle velocities, which are typical during a parking procedure, aid automatic control and detection of obstructions in the surroundings of a vehicle. 
     The present invention is therefore explained hereafter on the example of a parking procedure of a motor vehicle. 
     A motor vehicle  1  is shown in a schematic top view in  FIG. 1 . Distance sensors  3  are situated on a rear side  2  of vehicle  1 . Distance sensors  5  are also situated accordingly on front side  4  of the vehicle. A distance sensor  7  is also situated on a right vehicle side  6 . A distance sensor  9  is also situated accordingly on the left vehicle side  8 . 
     Distance sensors  3 ,  5 ,  7 ,  9  are implemented as ultrasonic sensors, for example. They measure the distances to obstructions in surroundings of the vehicle. The results of the measurement are forwarded to an analysis unit  11  via a data connection  10 . Analysis unit  11  has a computer unit  12  and prepares a map of the surroundings from the measured distance data to obstructions  13 ,  14  in surroundings of the vehicle. In order to measure a parking space  15 , the vehicle is guided along parking space  15  and obstructions  13 ,  14 . A traveled route is detected via a route meter  16 . The measured distance values are related by computer unit  12  to the distance values measured in particular by distance sensor  7  on right vehicle side  6 . For example, if a parking space is determined on right vehicle side  6 , both the length and also the width of the parking space are advantageously compared to vehicle data, which are stored in a memory unit  17  of analysis unit  11 . If the parking space is large enough, computer unit  12  calculates a driving route which guides the vehicle from a current position into parking space  15 . A corresponding trajectory  18 , along which the vehicle is to be guided, is shown in  FIG. 1 . 
     In a first specific embodiment, a drive unit  20 , a steering unit  21 , and a brake unit  22  are controlled by analysis unit  11 . By steering, accelerating, and braking vehicle  1 , the vehicle may now be guided along previously calculated trajectory  18  into parking space  15 . 
     In order to ensure according to the present invention that a driver monitors a driving space  19  at rear side  2  of the vehicle even during automatic guidance of the vehicle, analysis unit  11  is equipped via an interface  23  with a device  24  for approving the automatic guidance of the vehicle. A travel direction, in which the vehicle is to be controlled during the automatic guidance, is transmitted from analysis unit  11  via interface  23  to device  24  for approving the automatic guidance. The specification of the travel direction may include a rough specification, for example, forward or backward, in one specific embodiment, but in another specific embodiment it may also include a more precise direction specification by specifying a planned steering angle or steering angle curve. 
     A camera system  26 , which detects a viewing direction of the driver in the direction of rear driving space  19 , is connected to an interface  25  of device  24  for release. In a first specific embodiment it is provided for this purpose that camera system  26  detects the eyes of the driver. As long as the driver looks forward, i.e., in the direction of vehicle front side  4 , the pair of eyes of the driver may not be detected by camera system  26 . The pair of eyes of the driver is only detected when the driver is turned around. The relevant images of the camera system are analyzed by a computer unit  27  of the device for release. In one specific embodiment, device  24  for release may have a memory apparatus  28  for release, in which specific optical facial features of the driver are stored. In a further specific embodiment, instead of or in addition to a facial feature of the eye position, other facial features may be used for monitoring the viewing direction in this case, as well. These facial features may be a position of an ear or a position of the mouth of the driver, for example. 
     Furthermore, it is also possible, in particular in the case of a vehicle having head support, to accordingly detect a position of the head on the left and/or right side(s) of the head support, for example by a capacitive sensor system which is integrated in the head support for detecting a position of the head. 
     In a further specific embodiment, alternatively or additionally to the detection using camera  26  in a rear space of the vehicle, which is directed toward the driver, a camera  29  may also be provided in a front area of the vehicle, in particular in the dashboard of the vehicle. Camera  29  may accordingly detect a head orientation of the driver in the travel direction or [be] turned to the rear, i.e., in the direction of driving area  19 . 
     In one specific embodiment, the field of vision is solely estimated in accordance with the detected eye position, head position, and/or other facial features. It is accordingly possible to provide corresponding limiting values for a detected eye or head position, for example, from which a look of the driver to the front through a windshield or a look of the driver to the rear through a rear window of the vehicle is established. Such an ascertainment may be sufficient for determining the field of vision for an application according to the present invention. This is because, since the field of vision of a human has a horizontal extension of a total of approximately 170°, it is possibly not necessary to detect the exact viewing direction of the driver through a rear window of the vehicle toward driving space  19 . According to the present specific embodiment, it is only assessed whether the driving path, which the vehicle takes and which is fully visible through a rear window of the vehicle, is in the field of vision of the driver. 
     In the case of a more precise possible detection of a viewing direction of a driver, in a further specific embodiment, it may also be determined, for example, that the driving path of the vehicle must lie in a field of vision of the driver which ensures a color detection of the image via the eye and which only covers a horizontal angle of at most approximately 50°. 
     If it is determined by device  24  for release that driving space  19  is in the field of vision of the driver of the vehicle, automatic control of the vehicle is approved via analysis unit  11 . In a further specific embodiment, it is additionally monitored whether the driver continues to monitor the driving path during the automatic guidance of the vehicle, i.e., the driver remains turned around toward driving area  19  of the vehicle along trajectory  18 , for example, and thus still has the driving path in his field of vision. If it is determined at a later point in time that the driver no longer looks in the direction in which vehicle  1  is moving, by forwarding relevant information to analysis unit  11 , device  24  for release causes the vehicle to be decelerated by an action on drive unit  20  and/or on brake unit  22 , possibly to a standstill. If necessary, a corresponding warning may be output by analysis unit  11  via an output unit for this purpose, for example, a signal tone via a loudspeaker  30 . In one specific embodiment, it may also be provided that for the case in which it is determined that the driver no longer has the driving path for automatic control in his field of vision, an acoustic warning is first output. Automatic deceleration is now performed with a time delay, for example two seconds, when the driving path is no longer detected by the field of vision of the driver. It may thus be prevented that briefly looking away to monitor other vehicles in the surroundings of the vehicle, for example, may already trigger automatic deceleration of the vehicle. 
     Possible positions for camera systems are shown in  FIG. 2 . A driver  32 , whose face  33  is detected by one or multiple camera systems in a vehicle, is shown in a motor vehicle  31 . A first possible camera position  34  is shown on an A column of the vehicle in proximity to a vehicle roof  35 . In order to detect a viewing direction of the driver toward a rear vehicle space  36 , a further camera system  37  is situated on a vehicle rear side alternatively or additionally thereto. In a further specific embodiment, a camera system may also be provided on the dashboard. In one specific embodiment, camera device  38  is integrated into a head-up display, for example, and observes the driver via the optical pathway, in which a virtual image is overlaid in a windshield  39  of the vehicle. 
     A corresponding illustration of the various fields of vision and viewing of a driver  40  in a vehicle  41  is shown in  FIG. 3 . The driver may observe a rear driving space  43  through a rear window  42 . Viewing angle range  44  which is absolutely required for observing rear driving space  43  is shown by a dashed line. If eyes  45  of driver  40  are in the position shown here, his field of vision  46 , which is also shown by dashed lines, is sufficient for the purpose of overlooking entire viewing angle range  44  and thus driving space  43 . A corresponding observation of the driver may be performed for this purpose via a camera system  47 . In a first specific embodiment, automatic guidance of the vehicle in a reverse direction is already approved if it is determined that field of vision  46  covers angle range  44 . In a further specific embodiment, it may also be provided that a central horizontal field of vision range  48  of the driver of +/−20° must completely detect angle range  44 . In a further specific embodiment, a camera  49  may additionally be provided on a front corner of a vehicle roof  50  of vehicle  41  for monitoring automatic forward travel of the vehicle, in order to monitor a look  51  of the driver in a frontal direction of the vehicle for automatic control of the vehicle in a forward travel direction. Accordingly, an eye position  52  corresponding to viewing direction  51  is shown. 
     In addition to complete guidance of the vehicle via steering, acceleration, and braking, in another specific embodiment, partial automatic guidance of the vehicle may also be approved accordingly via a device  24  for approving automatic guidance, for example automatic steering of the vehicle, while the longitudinal guidance (i.e., the acceleration and braking of the vehicle) still resides with the driver. Accordingly, automatic acceleration or braking of the vehicle may thus be hindered or stopped, as long as the driver is not looking in the direction in which the automatic steering guides the vehicle. 
     An exemplary embodiment for a performance of the method according to the present invention is shown in  FIG. 4 . Starting from an initialization step  61 , detection of a parking space is started. In a subsequent measuring step  62 , vehicle surroundings are measured and potential parking spaces are measured with respect to their length and/or their width, in particular by distance sensors  7 ,  9 , which are situated laterally on the vehicle. If a suitable parking space has been, found, in a calculation step  53 , a parking trajectory from a current vehicle position into the ascertained parking space is calculated. In a subsequent warning and transfer step  54 , the driver is informed, for example with the aid of an acoustic output via loudspeaker  30 , of the fact that automatic guidance of the vehicle will now be performed. The driver may optionally start the automatic method during warning and transfer step  54 , for example, by a manual confirmation. Furthermore, it is also possible that an automatic start is performed. Subsequently, the sequence branches to a first testing step  55 , in which it is checked whether the driving destination, i.e., the final position of the vehicle in the parking space, has been reached. If so, the sequence branches to a final step  60  and the vehicle is stopped in the parking space. 
     If the driving destination has not yet been reached, instead the sequence branches from first testing step  55  to a second testing step  56 . In second testing step  56  it is checked whether a driving path of the vehicle is in the field of vision of the driver. This is performed, for example, as explained above, via at least one camera system and computer unit  27 . For this purpose, it is checked, for example, whether a camera on a roof of the vehicle near the rear window detects both eyes of the driver. If both eyes are detected by the camera, it is determined by the computer unit that the rear driving area of the vehicle is in the field of vision of the driver. Thus, if it is determined that the driver is looking in the travel direction, i.e., that his field of vision covers the essential driving area of the vehicle, the sequence branches to an activation step  57 , in which the vehicle is guided along the driving route. Subsequently, the sequence branches back to first testing step  55 , so that a check may be performed again after a particular prescribed driving distance, for example after 10 cm. 
     In contrast, if it is determined in second testing step  56  that the driver is not overlooking the driving space, that he looks to the front, for example, while the vehicle drives in reverse and therefore the driving path of the vehicle is not in the driver&#39;s field of vision, the sequence branches to a warning and pause step  58 . If the vehicle is not yet moving, automatic guidance of the vehicle is not performed and a warning is optionally output to the driver, for example by the output of a warning tone via loudspeaker  30 . If the vehicle is already in automatic guidance and is moving, a preferably acoustic warning is also output. In a further specific embodiment, the vehicle is additionally decelerated by a reduction of drive power and/or braking. Subsequently, the sequence also branches back to first testing step  55 . In a first specific embodiment, it is sufficient that the driver looks again in the particular direction of the driving path of the vehicle to continue the automatic driving. In a further specific embodiment, it may also be provided that an additional manual approval of the automatic driving by the driver is required.