WO2005118372A1

WO2005118372A1 - Method for holding the course of a vehicle

Info

Publication number: WO2005118372A1
Application number: PCT/EP2005/005641
Authority: WO
Inventors: Ingo Dudeck; Axel Gern; Rainer Möbus; Volker Oltmann; Uwe Regensburger; Reinhold Schöb; Bernd Woltermann; Zoltan Zomotor
Original assignee: Daimlerchrysler Ag
Priority date: 2004-06-02
Filing date: 2005-05-25
Publication date: 2005-12-15
Also published as: DE102004027085A1

Abstract

The invention relates to a method for holding the course of a vehicle and for warning the driver. According to said method, the current driving situation of the vehicle is determined in relation to the environment, and the behaviour of the driver is observed. If a possible deviation from the pre-determined course is identified, influence is exerted both on the driver and on the vehicle in differently distinct steps, the moment, duration, type and distinctness of each step being adjusted according to a risk potential which is deduced from the behaviour of the driver and the driving situation of the vehicle at the actual, acute moment.

Description

Vehicle tracking method

The invention relates to a method for tracking a vehicle according to the preamble of claim 1.

A large number of methods and systems are known from the prior art which serve to keep a vehicle, for example a truck, in a predetermined lane and, if appropriate, to warn the driver of the vehicle if the vehicle threatens to unschedule this desired lane leave. Such systems and methods are generally summarized under the generic term “LDW” (lane departure warning) or “LKS” (lane keeping system) and are increasingly used in vehicles.

The simplest variant of such systems only includes informing or warning the driver. The system alerts the careless driver to the fact that the vehicle will soon leave the lane or has already left it. Once informed of this, the driver should then steer the vehicle back into the intended lane. However, warning is often no longer sufficient, e.g. if the driver is completely tired or, given the current speed of the vehicle, the time left for the driver to react after the warning has been given is not long enough to take the necessary countermeasures. took initiate. For this purpose, systems are known from the prior art in which a warning mechanism is coupled with active intervention measures, such as, for example, an active steering intervention or active brake intervention.

From the German published patent application DE 198 30 548 AI, for example, a steering control device is known which, depending on the deviation of the vehicle from predetermined reference lines, exerts a corresponding steering torque in order to support the driver, who may be suffering from fatigue, and to bring the vehicle back to the predefined one Lead lane.

Furthermore, it is known from German published patent application DE 103 11 518 AI to allow the driver's behavior, in particular the previous behavior, in particular his steering behavior, to be included in the assessment of the actual risk potential in the event of such a deviation before the vehicle threatens to deviate.

All systems combine object detection systems well known from the prior art, which visually detect the surroundings of the vehicle, in particular the front area, and in-vehicle sensors, which parameters for the current driving situation of the vehicle, such as Includes speed, lateral acceleration, turning speeds etc. as well as parameters for the behavior of the driver.

The disadvantage of all methods and systems is that they cannot be adapted adaptively to the driver on the one hand and to the current driving situation of the vehicle on the other. Under certain circumstances, this can lead to false warnings to which the driver does not respond, or to incorrect assessments of such sensor-related false warnings, which considerably reduces the acceptance of such systems by the drivers. There may be situations in which the time to inform or warn the driver and / or the active intervention does not occur at the point in time at which the dangerous situation outside the vehicle is actually detected.

For example, the situation is to be mentioned in which, when the vehicle begins to deviate without having already crossed the sideline, the driver is only briefly inattentive because he e.g. is currently operating the radio, compared to a situation in which the driver obviously goes into a second sleep phase. In the latter case, the warning must be given much earlier, since it is to be expected that the driver's responsiveness will be reduced due to his tiredness and thus his reaction time will be considerably longer compared to the first example. In other words, the hazard potential is significantly higher in the last example, although in both cases the vehicle has not actually strayed critically from the specified lane.

Proceeding from this, it is the object of the present invention to provide a method which, on the one hand, enables the driver to adapt to the situation or is warned of the unwanted departure from the lane and, on the other hand, appropriate intervention measures.

This object is achieved with a method according to the features of patent claim 1.

In particular, the invention is characterized in that the driver and the vehicle are influenced in different clear forms which are graduated from one another. The forms or stages of influencing essentially include informing the driver, warning the driver and, if ultimately necessary, also intervening in the control of the vehicle. It is provided according to the invention that the point in time, the duration, the level and the extent of the respective influence is determined as a function of a hazard potential determined at a particular point in time, this hazard potential combining the behavior of the driver and the driving situation of the driver Vehicle can be calculated. By regulating the extent of influence, further gradual gradations of the clarity of the influence, ie its perceptibility by the driver, are possible within the three stages - information, warning, intervention. With such a gradation of the influence with regard to its clarity, it is achieved that the driver does not become dull against too many similar indications of a lane monitoring system.

It is further advantageous for the driver to accept the method if, in a current dangerous situation in which one or more influences have already occurred, to which the driver does not respond adequately, the influences can be continued step by step with increased clarity. The clarity can be regulated by choosing the next higher level from the sequence - informing, warning, intervening - and / or by a combination of the levels and / or the extent of the measures chosen

The driving situation of the vehicle is detected by well-known object detection systems, such as radar, lidar, camera systems or systems based on digital maps (digital horizon and map attributes), possibly coupled with blind spot systems. With such systems, the course of the lane can be determined on the basis of the detected lane and on the basis of the lines running on this lane. The object detection systems then relate the vehicle to the detected lane. In addition, these systems can recognize objects, such as oncoming vehicles and other vehicles located to the side or behind the vehicle. In a detection and Calculation of the course of the lane can also include an object recognition for recognizing vehicles driving ahead or for recognizing stationary objects.

All data from "external" detection systems are offset against "internal" sensory measurements, such as, for example, the speed, lateral acceleration and so on, it being known that torque sensors, torque adjusters, yaw rate meters and so on can be used.

According to the invention, a large number of parameters flow into the determination of the hazard potential and its assessment.

An important parameter is, for example, the type of road on which the vehicle is traveling. In this way, different strategies can be defined when assessing the hazard potential, depending on whether the vehicle is moving on a motorway, a federal road or a country road. For example, it can be considered to switch off the procedure on country roads if the corresponding road layout can be classified as sufficiently varied and therefore not dangerous for the driver.

Another criterion is the lane width. The smaller the lane width, the shorter the time at which the vehicle can drive over the side lane marking. Accordingly, the hazard potential must be classified higher and, for example, a warning time must be set earlier.

Another criterion is the degree or extent of the curvature of the lane or a curve. For example, the driver has to be warned more quickly when coming into tight bends than with long bends, since the risk of deviating from the lane at the same speed is considerably higher. Depending on the speed, the system can actively intervene in the control of the vehicle. Under certain circumstances, it should be possible that the curve can be cut explicitly. Here, however, a warning when cutting a curve is only issued if the vehicle-side object detection system detects that a vehicle is in the neighboring lane. This can be done for both the front and a blind spot system for the rear vehicle area.

Another parameter that is included in the assessment of the hazard potential is the type of lines that are on the road. In this way, it can be set that the driver is informed or warned only when crossing single or double solid lines. If, for example, solid lines are at a construction site, the environment and thus the lines are detected based on the vehicle-based object detection system, and it is determined that this is a construction site.

Furthermore, the hazard potential when crossing a solid line can vary so that it is determined differently for different widths of the hard shoulder or hard shoulder, if there is one. With a wider hard shoulder, the hazard potential is lower than with a less hard shoulder because the driver has less space and therefore time to react. Accordingly, the hazard potential is very high if there is no hard shoulder or if an object, such as a vehicle that has broken down, is detected on the hard shoulder. The presence and the width of the hard shoulder as well as a vehicle on the hard shoulder can in turn take place via the known object detection systems in the vehicle. If, for example, there is another vehicle on the hard shoulder or the road closes with a guard rail without hard shoulder, according to the invention the time can accordingly be set such that the driver is warned or the control of the vehicle intervenes before the vehicle is actually driven over lateral lane marking takes place so that a sufficient safety distance to the vehicle or to the guardrail remains depending on the time still available.

According to the invention, in addition to these “external” parameters, the “internal” parameter of the driver's behavior also flows into the assessment of the potential hazard. Both the current behavior and the behavior of the driver preceding the dangerous event are of interest here.

The behavior of the driver is particularly important when the driver's fatigue or alertness is to be assessed. Here, too, there are already several proposals in the prior art which focus on detecting the driver's eyelid or eyelid movement.

In combination with the other parameters, the warning threshold is significantly reduced when the driver is tired, so that the response time in the event of a warning if the vehicle leaves the lane can take effect more quickly.

Fatigue can be determined, for example, by the steering activity and / or guidance of the vehicle in the lane. For example, if the driver performs only minimal steering and pedal movements that no longer meet the current driving situation, this indicates a tired state. With high steering activity, on the other hand, a warning threshold can be set higher because this behavior suggests active participation in traffic. The number of false warnings can be advantageous by means of such measures reduce, since a warning of leaving the lane is only triggered if the driver actually lacks a certain amount of attention or is tired.

Another criterion for the level of driver attention is whether the driver's hands are in contact with the steering wheel. This can be detected via pressure sensors integrated in the steering wheel or via capacitive sensors. If the hands are not on the steering wheel, early information is given to the driver and, if there is a risk of lane departure, an early warning is given to the driver. The same applies if the electronics in the vehicle recognize that the driver is operating other units at the acute time, for example the radio, the air conditioning system and so on, since this suggests that the driver is distracted from the road at least for a short time. If the vehicle threatens to deviate, the warning threshold is reduced accordingly under such conditions.

The system which implements the method according to the invention can be coupled to one of the well-known navigation systems. In this way, all data relating to the type of road, curvature, type of lines and so on for the current location and a preview of a larger area can also be obtained from a map stored in the navigation system.

In this context, warnings and intervention in the steering of the vehicle are not carried out if the route guidance of the navigation system can be demonstrated to have been followed or the driver has given instructions from this navigation system, for example when changing lanes to a motorway exit, even though he has forgotten the direction indicator to activate. The parameters and mechanisms described above, which influence the time of the warning or of the intervention, are used in principle according to the invention for the evaluation of the hazard potential. Depending on the hazard potential defined in the respective state on the basis of these parameters, the individual forms or stages of influencing - informing, warning and, if necessary, intervening - are selected and carried out. According to the invention, the exact shape, duration and variability of the individual stages are determined by the prevailing hazard potential, which can change quickly within the short period of time that is available at the speeds of vehicles that usually occur.

Accordingly, in the case of a low hazard potential, the method according to the invention begins with a pure information to inform the driver that there is a hazard potential. If the risk potential rises, for example if there is a clear deviation from the lane, but there is still enough space for the driver to react, the method according to the invention opens up the possibility of specifically warning the driver. However, should the risk potential increase significantly because the driver neither reacts to the information nor to the warning, for example if the driver should actually have fallen asleep, the method according to the invention provides for active control of the vehicle, possibly supporting a delayed reaction of the driver tired driver to intervene.

In the event of a high risk potential, the driver can be warned and the vehicle's control system intervened at the same time. In other words, according to the invention, it always depends on the hazard potential ascertained whether a graduated influence of the form: informing - warning - intervening is observed, or whether a warning or an intervention in the control takes place immediately. According to the invention, the information and / or warning can be carried out in a visual, acoustic, haptic or other way.

Optical information and / or warnings can take place by means of a flashing indicator, it being provided according to the invention that the flashing frequency and / or possibly the color of the flashing indicator changes depending on a hazard potential, that is to say the flashing frequency increases with increasing hazard potential and, for example the color changes from orange to red.

The same applies to an acoustic signal to the driver. If there is an increased risk potential, the frequency of a tone sequence and / or the volume of this tone may increase.

In the case of a haptic system, for example, the steering wheel and / or the driver's seat is set to vibrations, the frequency of the vibrations being able to change as a function of the hazard potential. The greater the hazard potential, the more violent the vibration of the steering wheel and / or the seat.

Another possibility, which indicates to the driver of an impending abnormal driving course, can be accomplished by briefly tightening the belt using reversible belt tensioners in order to exert a force on the driver that is intended to draw his attention to the driving situation. According to the invention, it is possible to implement the extent of the belt tightening and also the speed of the belt tightening as the danger potential increases. A brief braking intervention can also be carried out in order to draw the driver's attention to the current driving situation. Of course, all the measures and means described above can be adequately combined with each other.

If neither the information and finally the warning of the driver is of no avail because the driver is unable to react in an appropriate manner and in a reasonable time, the control of the vehicle is actively intervened as a final measure. These measures can include that with correspondingly arranged actuators in the vehicle, an active return steering movement is carried out or individual wheels are briefly braked so that the vehicle is led back into the lane.

However, if the vehicle-side detection system detects that the driver is no longer able to react, for example because he is now completely asleep, the entire vehicle can be braked according to the invention, possibly until the vehicle comes to a standstill, the hazard warning system also being used Warning of other road users can be activated. If the vehicle is on an outer lane and a hard shoulder is recognized, the vehicle can be actively steered to avoid collisions. Alternatively, it is possible to bring the vehicle to a stop at the edge of its own lane.

It is clear that the method according to the invention, which can be implemented electronically and with software support, can be used to adapt the individual information levels to the driver in a manner that is adaptable to the situation up to an active intervention in the control, so that critical states are avoided and Number of false warnings on the one hand and the number of actual warnings perceived as false warnings can be reduced. An exemplary embodiment is given below to illustrate the method according to the invention.

A monotonous drive on a road-like, that is to say essentially straight-ahead route with large curve radii is assumed, the driver either being distracted or tired.

The vehicle begins to leave the intended lane or the lane given by the course of the road. The vehicle-side optical lane detection system recognizes that the vehicle is about to deviate from the road due to the lateral speed / acceleration of the vehicle and the changed distances to the solid lines on the side. The system which implements the method according to the invention outputs a first haptic signal to the driver by vibrating the steering wheel. The driver should feel this if his hands are on the steering wheel and initiate appropriate corrective steering movements (warning level 1).

If the driver does not react, a corresponding warning signal is output, which can be of an acoustic and optical type, for example, by flashing with a corresponding tone repetition frequency and / or a corresponding tone (warning level 2).

If it is recognized in the vehicle's fatigue detection system that the driver no longer shows the attention necessary for driving a vehicle or can no longer maintain it, a belt tensioner is briefly activated in order to "wake up" the driver (warning level 3).

If there is no or only an insufficient driver reaction after the belt tensioning, there is an active intervention in the steering via a steering divider provided in the vehicle. As a result, the vehicle direction is actively corrected to a limited extent by the system (warning level 4). If there is still no or only insufficient reaction on the part of the driver, independent wheel braking is also initiated to keep the vehicle on track (warning level 5).

If for some reason the driver is unable to react accordingly despite the already active influence of the vehicle system, the vehicle is finally braked until it comes to a standstill, whereby the other road users can be warned by activators of the hazard warning lights (warning level 6 ).

Claims

claims

Method for keeping a vehicle in a predetermined lane, in which the driving situation of the vehicle is detected and the behavior of the driver is monitored, and in the event of an impending departure from the lane, the behavior of the driver and the driving situation of the vehicle are influenced, characterized in that that the influencing takes place in differently clear stages, as informing the driver and / or warning the driver and / or intervening in the control of the vehicle, the time, duration, extent and the level of influencing being selected as a function of a hazard potential , which is determined from the behavior of the driver and the driving situation of the vehicle.

Method according to Claim 1, characterized in that an influence which is repeatedly required within a dangerous situation is activated in a clearer stage than before, depending on the danger potential and on the driver's reaction to an influence which has already taken place.

3. The method according to any one of claims 1 or 2, characterized in that the information and / or warning for the driver takes place visually, acoustically, haptically and / or in another way.

4. The method according to claim 3, characterized in that the optical information and / or warning takes place by means of a display or flashing display, the color of the display and / or the flashing frequency changing depending on the hazard potential.

5. The method according to claim 3, characterized in that the acoustic information and / or warning takes place by means of a tone display, the tone frequency and / or tone repetition frequency and / or volume change depending on the hazard potential.

6. The method according to claim 3, characterized in that the haptic information and / or warning follows by means of vibration of the steering wheel and / or the driver's seat, the frequency of the vibration changing depending on the hazard potential.

7. The method according to claim 3, characterized in that the haptic information and / or warning takes place by means of a reversible belt tensioning, the force and / or the acceleration and / or the frequency of the belt tensioning depending on the hazard potential.

8. The method according to claim 3, characterized in that the haptic information and / or warning takes place by briefly braking and / or removing gas, the strength and duration of this measure changing depending on the hazard potential.

9. The method according to any one of claims 1 or 2, characterized in that the intervention takes place by means of a supportive or active steering movement and / or a track-correcting braking of individual wheels.

10. The method according to any one of claims 1 or 2, characterized in that the intervention takes place by braking the vehicle, even to a standstill.

11. The method according to claim 10, characterized in that the hazard warning system is additionally activated.

12. The method according to any one of claims 10 or 11, characterized in that when braking, the vehicle is directed to the side of the lane or on the hard shoulder or in an emergency stop or on a parking lot or on a hatched area.

13. The method according to any one of the preceding claims, characterized in that as a parameter for determining the hazard potential road type and / or road width and / or type and Width of the line markings and / or the extent of the curvature of the road on which the vehicle is moving are used.

14. The method according to claim 13, characterized in that the parameters are taken from a detection of the street and the surroundings of the vehicle and / or from a map stored in a navigation system.

15. The method according to any one of the preceding claims, characterized in that the hazard potential is determined depending on a current and / or a previous behavior of the driver.

16. The method according to claim 15, characterized in that the previous behavior of the driver is determined by recognizing the steering angle when steering in comparison to the lane traveled.

17. The method according to claim 15, characterized in that the current behavior of the driver via a detection of his viewing direction, a detection of the activity of his eyelids, a detection of whether the driver keeps his hands in contact with the steering wheel, a detection of whether the driver Operating controls in the vehicle are operated and / or a detection of an extent of its steering and / or pedal activity is determined.

18. The method according to any one of claims 15 to 17, characterized in that fatigue detection is used to detect the current behavior of the driver.

19. The method according to any one of the preceding claims, characterized in that the hazard potential is determined as a function of the lateral acceleration of the vehicle.

20. The method according to any one of the preceding claims, characterized in that the hazard potential is determined as a function of an approach speed to the lane edge.

21. The method according to any one of the preceding claims, characterized in that the hazard potential is determined as a function of an approach speed to vehicles and / or objects in neighboring lanes or at the edge of the road.

22. The method according to any one of the preceding claims, characterized in that the hazard potential is determined as a function of an approach speed to vehicles in their own lane.

23. The method according to any one of the preceding claims, characterized in that the hazard potential is determined as a function of detection of a passage through a construction site.