The present invention relates to a method for detecting a
Attention deficits of a driver in a moving motor vehicle,
and an apparatus for carrying out this method.
WO 02/17787 a method and a device are known in
which a control circuit without active intervention of the driver in the
Steering of the motor vehicle acts to the direction of travel of the motor vehicle
and a driver's attention deficit is detected when this one
not responding in a predetermined manner. Generally, the driver should
of a motor vehicle 100% control over the
Vehicle, to be sure that this is not in
because any unexpected behavior of the vehicle ultimately harbors
Risk of accidents. The cited script tries to solve this problem
to get around by the extent of the intervention
is kept so low in the steering of the motor vehicle, that
Noise goes down ", what
means that the extent of
should be considered as unforeseen direction changes due to
external causes such as road bumps, gusts, etc.
constantly occurring and continuously compensated by an attentive driver
smaller is such an intervention, the greater of course is the probability
that the driver does not respond to him in the expected way
because he perceives the procedure as too small, at all
compensation in need
to be, or because he is temporally with an external influence
overlapping on the direction of travel,
which conceals the procedure.
An attention deficit is detected, it is required within
Time to warn the driver to restore his attention,
or correctively intervene in the steering, in the latter
Case a degree of correction adapted to the situation
must, for example, to prevent an accident.
So the following dilemma arises: do you interfere with the
Vehicle steering, with which the driver's attention is tested
is to be too small, so is based on the reaction of the driver
a single such intervention no permissible statement about its
Attention level possible.
Instead, a variety of minor interventions and hires
Attention deficit only firm if on a sufficient number
such interventions no driver reaction takes place to the expected extent,
then a timely detection of an attention deficit is not
more is possible,
and the value of attention monitoring to
Prevention of accidents
is severely limited.
If you make the extent of the
Engaging so big
that every intervention requires a driver reaction,
so increases the risk of accidents when the driver of such an intervention
surprised at an inappropriate time
of the invention is a method and apparatus for detecting
of an attention deficit with a minimum
Number of interventions a reliable one
Assess the level of attention of the driver to each relevant
Task is solved by
that the position of the motor vehicle on a lane traveled by him
is to allow for any upcoming leaving the lane
recognize, and a review of
Attention of the driver by engaging in the steering and / or
Brake system then performed
will if the monitoring
indicates an imminent leaving the lane due to lack of
Attention of the driver could be caused. If, on the other hand, leaving
the lane is wanted by the driver, it can be assumed
that at this point he paid close attention to the course of the vehicle
gives and is capable of a noticeable intervention of the control circuit
to respond appropriately to the vehicle steering system. The review of
Attention is preferably given, if not certainly recognizable
is whether the driver is alert and intends to leave a lane
not just to test the driver's attention, but in the case
lack of attention at the same time reduce the risk of accidents,
should the intervention of the control circuit in the steering a leave
counteract the lane.
an attention deficit is detected, by generating a
Warning signal the driver's attention be restored.
This warning signal can be particularly optical, acoustic or
be haptic nature.
sufficient attention of the driver is found in particular then
if the counter steering within a predetermined period of time
the intervention takes place. Another criterion can be achieved
serve a predetermined deflection of the counter-steering movement.
an attention deficit is detected, may suitably
another engagement of the control circuit in the vehicle control
done to prevent leaving the lane. The extent of this
second engagement can be much stronger than that of the first.
The second intervention may in turn be an intervention in
the steering and / or the brake system, either to Einzelradbremsungen
or a braking of all wheels
of the motor vehicle.
The length of time that the driver's attention test procedure precedes a predicted lane departure time may be determined depending on one or more of the following parameters:
- - the width of the lane: the wider it is, the more pendulum movements of the motor vehicle can be allowed on the lane, for example, if the driver evades in oncoming traffic to the right lane boundary or evades when driving past passers to the middle of the lane.
- - the speed of the motor vehicle: the higher the speed and, consequently, the higher the risk potential, the lower the warning threshold may be.
- The angle between the heading of the motor vehicle and the course of the lane: a rapid increase in the angle, especially at low driving speeds, tends to suggest a deliberate driver's steering, whereas slow drifting may be due to a driver falling asleep or inattentive , The direction of drift may also be significant: drifting to the right and simultaneously decreasing speed may be quite a deliberate departure from a highway or expressway while driving to the left may be due to lack of attention as the speed decreases declining. Conversely, drifting to the left with increasing speed indicates a presumed overtaking maneuver, while an increasing speed when drifting to the right is probably not wanted. In the unwanted case, an early examination of the driver's attention is always appropriate. The time span can also be determined on the basis of the course of the movement direction (trajectories) of other road users. For example, the travel of preceding vehicles relative to lane markings may be considered.
for detecting the position of the motor vehicle on the lane in the
Rule anyway a detection of a lane marker such as one
Middle or marginal strip of the roadway will be erforder Lich,
Only little technical effort is required in addition to the
Type of track marking (wide or narrow, solid or broken)
capture. At the approach
A solid mark may be due to a lack of attention
of the driver and is an early review of attention
the vehicle over
has a navigation system,
can the inventive method
with little effort also information of the navigation system over the
Type of road used
use this information to calculate the speed,
the course of the vehicle in relation to the roadway, etc. as more
or less noticeable
to judge and over
the urgency of a test
to decide the attention. Also the nature of the environment, through
the the busy road
can be used as a criterion. So is about a curvy
in mountainous terrain with an approach to the lane edge
connected danger far greater than
on a highway with hard shoulder, so in the former case a
the driver's attention already at an easy approach
be appropriate to the roadside
can, whereas in the latter case, even the driving on the right edge strip
itself does not contain any immediate danger.
same criteria can
a decision over
the extent of
Engaged in the steering and / or braking system are used.
the driver on the intervention in the steering and / or brake system
reacts in the given way, a lane change is allowed without
the driver with a warning signal or another intervention in
to bother the steering and / or brake system.
A lane change has been approved for a certain period of time
be assumed by a high degree of attention of the driver,
so that a re-examination of attention can be omitted during this period.
All the more so as in a lane change from the right to the
left lane a renewed change in the opposite direction mostly after
follows a short time and is intended by the driver.
Further, various actions that the driver may perform in the vehicle may be considered indicative of a sufficient level of attention, such that when one of these actions is registered, further attention checking may be required conditions for a given period of time can be omitted. These actions may include in particular:
- The actuation of a driving, clutch or brake pedal,
- A steering movement,
- - a change of gait,
- - An operation of a switch, such as a turn signal, windscreen wiper, light switch, etc., to switches of additional devices such as navigation system or car radio.
Time span while
that's the attention check
can be, on the extent of
or the steering movement, the type of switch actuated or else
be made dependent on the vehicle speed.
In the vehicle a navigation system is active, can during capture
the vehicle to a lane boundary also be considered, whether at the same time
the navigation system suggests leaving the lane, and the
may be omitted if such a proposal exists. In this
Case can be assumed to be leaving the lane
by the driver, and a driver's attention by one
can be avoided. When deciding whether the attention check is performed
or not, can also be considered
be in which direction the proposal of the navigation system
According to the lane should be left, and in which direction
the vehicle approaches the lane edge. If both directions do not match,
nevertheless an attention check
Apparatus for carrying out
of the method as described above comprises in addition to a control circuit
to decide about
the need for intervention in the steering and / or brake system
of the vehicle and if necessary
Engaging in the steering and / or Bremseinlage one to the control circuit
coupled sensor for detecting the position of the motor vehicle relative
to a lane, and the control circuit is set up over the
Necessity of intervention on the basis of the results of the detection
Sensor to decide.
Features and advantages of the invention will become apparent from the following
Description of exemplary embodiments
with reference to the attached
Characters. Show it:
1 a schematic representation of a vehicle equipped with a device according to the invention, which moves in a lane;
2 a block diagram of a monitoring device of the vehicle with servomotor and adder; and
3 a flowchart of a working method of the monitoring device.
In 1 is a schematic plan view of a motor vehicle 1 Watching that on a right lane 2 a two-lane road moves. The lane 2 is provided with a lane mark on the right and left; on the right side in the form of a solid border strip 3 marking the transition to a non-drivable siding or the like, and on the left a median strip 4 which can be interrupted or pulled through as shown.
The car 1 is with at least one, in this case two cameras 5 equipped, each along an optical axis shown as a dotted line on an obliquely in front of the motor vehicle 1 lying area of the lane 2 are aligned to there the lane boundary strip 3 respectively. 4 capture.
As in 2 shown are the two cameras 5 to a control circuit 6 coupled. The control circuit 6 comprises a microcontroller with an image processing program designed in a manner known per se to be in from the cameras 5 supplied images each the lane boundary marker 3 or 4 to recognize and from the distance δl or δr of the vehicle from the left or right edge of the lane 2 to calculate.
The control circuit 6 is also to a sensor 7 connected, for detecting a driver turned nen steering angle on the steering wheel 8th of the motor vehicle is used. The position of the steerable wheels of the vehicle is in this embodiment by a servomotor 9 depending on the sensor 7 controlled steering angle controlled. For this purpose are the sensor 7 and the servomotor 9 via an adder 10 connected, the one with the control circuit 6 connected input and it has the control circuit 6 so allows the position of the wheels slightly different from that of the driver on the steering wheel 8th to control the adjusted position. In this context, alternatively, it is also possible to use steering systems with torque actuators. The monitoring device can also be designed such that it acts in addition to the steering on the brake system of the motor vehicle, for example by means of Einzelradbremsung.
The control circuit 6 is also to a data bus 11 connected to the vehicle, among other things, serves to control commands from various in the passenger compartment of the motor vehicle 1 arranged switches or controllers to receive or transmit to associated actuators at other locations of the vehicle, such as a windshield wiper switch to a windshield wiper drive motor, from a remote or dimmer light switch to a corresponding relay of a headlamp, etc .. About the connection to the data bus 11 is the control circuit 6 able to receive all of these commands and their appearance on the data bus 11 in the case of switches normally operated by the driver, to conclude that the driver is awake.
A preferred embodiment is according to the data bus 11 also a vehicle navigation system 12 connected, which determines the geographical position of the vehicle in a conventional manner based on received radio signals, identified on the basis of entrained cartographic information a road on which the vehicle is located, and on the basis of previously entered by the driver information about a destination with the driver Information about a track to follow.
According to the invention, it is provided that this navigation system 12 In addition, information about the route to be traveled, in particular about a soon to leave the currently traveled lane to the right or to the left as well as information about the nature of the just passed environment in from the control circuit 6 evaluable form on the data bus 11 outputs.
The operation of the control circuit 6 is based on the flowchart of 3 explained.
The first processing step S1 is the determination of the distance δl, δr of the motor vehicle 1 from the left or right lane boundary marking, here the edge or middle strip 3 respectively. 4 , by means of through the cameras 5 supplied images, and the judgment whether the mark is a solid or an interrupted strip. If the roadway no such stripes 3 or 4 has, the image processing program of the control unit 6 expediently designed to road boundary posts 13 to identify and to judge the distance to them.
tested in step S2,
whether the driver has taken any action that concludes
allow him to be alert and alert. Such actions can, like
a switch, but also the operation of the driving, coupling
or brake pedals, in a vehicle with manual transmission, a gear change,
or an operation
be the steering wheel. As a steering wheel movement is not excluded
is when the driver has dropped in second-sleep, this is as
Note that the alertness of the driver can only be valued
if they have a given minimum speed or minimum deflection, over one
Certain value achieved.
If it is determined that the driver has performed such an action, in step 3 set a blocking time whose length can be specified differently depending on the nature of the detected action, and whose function is also explained. Subsequently, the method returns to the output and, possibly after a predetermined waiting time, starts again with step S1.
If no action of the driver is detected in step S2, it is next checked in step S4 if a lock time set in a previous step S3 has elapsed. If not, the process also returns to the exit, if yes, it checks in step S5 whether one of the measured distance values .DELTA.R is .DELTA.L is less than a corresponding minimum value .DELTA.R min respectively, .DELTA.L min, These two limit values can be the same, it may but also the limit δl min be chosen smaller than δr min , because in many cases those with the approach to the median strip 4 connected danger is less than that at too close approach to the right edge of the road. In general, the limit for the approach to a solid boundary strip can be set higher than for the approach to an interrupted. If lack of boundary strip 3 . 5 Roadway delineator 13 This is of course taken into account when determining the limit values δr min or δl min .
In principle, the illustrated method may be interrupted at any time in order to update the limits δr min , δl min based on information about the surroundings of the vehicle, for example by δl min increase to V , if one of the two cameras 5 Oncoming traffic in the left lane detected, and after passing the oncoming traffic to reset the limit value to its original value, or to raise δr min if from the navigation system 12 receiving information indicating that the vehicle is moving in mountainous terrain and could be on a slope beyond the right-hand lane edge.
If the limit values δr min , δl min are not undershot, the control circuit calculates 6 Based on values of δl, δr obtained at successive iterations of the method at different times, the speed dδl / dt, dδr / dt, with which the vehicle approaches the left or lane edge approaches (S6), and from an estimated time Tl, Tr until reaching the left or right lane edge (S7). These times are respectively compared with limits Tr min , Tl min in step S8, and if they do not fall below the limits, it is determined that the vehicle is safely on its lane, and the process returns to the exit. If one of the calculated times Tr, Tl falls below the assigned limit value, it is first checked in step S9 whether route information from the navigation system 12 that could be a reason for leaving the lane to the right or left. If so, it is assumed that an eventual lane departure from the driver is intentional, and the process also returns to exit.
If no route information justifying leaving the lane is from the navigation system 12 is present, the control circuit leads 6 As shown in this example, in step S10, an intervention in the vehicle steering system by sending it to the adder 10 outputs a control signal that opposes leaving the lane. Alternatively or in addition to an intervention in the steering system, an engagement in the brake system may take place here, for example in the form of individual wheel braking. Subsequently, in step S11, the control circuit monitors 6 the output signal of the sensor 7 to determine if the driver is performing a counter-steering movement. If this is detected, it can be concluded that the driver is awake and attentive, and that he really wanted to leave the lane. In this case, the method also returns to the exit, optionally, as indicated by a dashed arrow in FIG 3 indicated via the step S3 of setting a lock time.
If the driver's backlash is not detected within a predetermined time in step S11, this indicates a driver's lack of attention. The response of the control circuit to it in step S12 may consist of the simple output of an optical, audible or haptic warning signal to the driver, but it may also vary, depending on how the control circuit 6 assessed a possible current threat. If a driver's backlash is detected, but it is weak or comes with a great deal of delay, the driver is obviously still awake, but may be tired or unfocused, and a simple warning may be sufficient. This can eg in the operation of a light indicator, a buzzer, the output of a voice message, eg via the data bus 11 and one of the Naviga tion system 12 used speakers, in the operation of a built-in steering wheel vibrator or the like. If a counter-reaction is completely absent, so that it is to be feared that the driver has fallen asleep, further interventions by the control circuit can also be performed in step S12 6 when driving such as increased steering intervention to the vehicle in the lane 2 to stop, or a stunt should be indicated. In order to limit such interventions to an actual emergency, it can be provided that they are only performed if other steering interventions S10 have already been carried out in an immediately preceding period of several minutes and, following this, a delayed counter-reaction of the driver is observed in step S11 has been.