The present invention relates to a driving assistance system for motor vehicles, a method for the haptic warning of a driver of a motor vehicle, and the use thereof.
Modern driving assistance systems for motor vehicles are intended to warn the driver of hazardous situations. One example thereof is a so-called lane departure warning system, which monitors via sensors, for example a camera, ultrasonic sensors, radar signals, or the like, whether there is a risk of the vehicle leaving the roadway, whereupon a warning signal is generated (see, for example, German patent documents DE 10 2006 032 554 A1 or DE 10 2006 050 214 A1).
Distance warning systems operate in a similar manner; such systems measure the distance of the vehicle from a preceding vehicle or an obstruction, and as a function of the vehicle speed and the distance ascertain whether there is a risk of collision.
Other systems monitor the attentiveness of the driver, using, a camera, by observing the driver's eye movements, blinking frequency, or the like, and likewise generate a warning when an attention deficit is determined.
In addition to acoustic and optical warnings, it is known that haptic warnings are also very effective. Such warnings are very quickly received, do not distract the driver, and intuitively and directly lead the driver to a correct response. Thus, the driver automatically associates vibration of the steering wheel, for example, with the steering operation, and his attention is guided directly to the roadway lane. In the above-mentioned lane departure warning system it is therefore also known to initiate vibration of the steering wheel when a lane sensor generates a warning signal.
However, setting the steering wheel into vibration requires appropriate control elements or actuators. In practice, this has been achieved heretofore using an electrically activatable power steering system, which in many compact and midsize passenger vehicles is available instead of a strictly hydraulic power steering system. However, such steering systems have not been available thus far in heavy-duty utility vehicles, since reasonable electrical generation of the necessary steering forces has not been possible heretofore.
An object of the exemplary embodiments and/or exemplary methods of the present invention, therefore, is to improve a driving assistance system and a method for the haptic warning of a driver of a motor vehicle in such a way that an effective haptic warning may be generated with little complexity. This object is achieved by the features described herein as to the related system, the method, and the use thereof.
An aspect of the exemplary embodiments and/or exemplary methods of the present invention lies in using the reaction of the braking forces of the vehicle brake to generate a haptic warning signal.
Various interesting options are thus provided, namely,
As a result of the application frequency of the individual brakes and the braking force triggered in each case, different haptic patterns may be generated which are adapted to the particular hazardous situation, for example the situations of lane departure, imminent collision, excessive speed, fatigue or inattentiveness of the driver, etc.
Implementation in present utility vehicles is possible with little complexity, since most modern utility vehicles are already provided with an electronic braking system (EBS) or electronic stability program (ESP) which allows autonomous application of the individual brakes of the vehicle. Therefore, no additional actuators are necessary for generating the desired haptic warning.
Thus, in practice, with the assistance of the electronic braking system or the ESP, a slight brake pressure on the front axle may be requested which alternates on the left and right sides, and which at the appropriate frequency is perceivable as vibration on the steering wheel. The driver may thus be made aware of a departure from the roadway lane.
When a slight brake pressure is cyclically requested on the front axle with the assistance of the electronic braking system or the ESP, the driver perceives this similarly as he does a “washboard” roadway.
A single, brief braking jerk is perceived as driving over an obstruction. Both described types are suitable as a warning for an imminent collision.
When, with the assistance of the electronic braking system or the ESP, a slight brake pressure on the front axle is requested which is randomly distributed to the left and the right sides, this is perceived by the driver as a very uneven roadway.
The cyclical braking interventions may be superimposed as the result of a pressure differential between the left and right sides in order to achieve a given steering effect which is a function of the roll radius. The-driver may thus also be provided with a steering instruction concerning which direction he is to turn the steering wheel in order to make a lane correction which may be necessary.
In brief, the exemplary embodiments and/or exemplary methods of the present invention therefore provides for the use of a motor vehicle brake system for the haptic warning of a driver.
According to the method of the present invention this is achieved on the basis of a signal of a hazard sensor, in that the signal of the hazard sensor momentarily activates braking of a vehicle. This may be carried out multiple times in alternation on the front axle brakes of a left front wheel and a right front wheel, or at least on all front axle brakes simultaneously, in particular multiple times cyclically, multiple times randomly, or a single time.
All known sensors, for example cameras, distance measuring instruments based on ultrasound, radar, etc., may be used as hazard sensors.
The exemplary embodiments and/or exemplary methods of the present invention are explained below with reference to one exemplary embodiment in conjunction with the drawings.
The vehicle also has a hazard sensor 11 which, for example, is a lane sensor for scanning the roadway, or a distance sensor for measuring the distance from an obstruction or a preceding vehicle. Of course, multiple different sensors may be provided, all of which are connected to central control unit 10. The two front wheels 2 and 3 are connected in a known manner to a steering system 14 via a steering linkage 12 and optionally a steering gear 13.
The function of the haptic warning is carried out by the combination of hazard sensor 11 of central control unit 10 and brake actuators 6 and 7, and also optionally brake actuators 8 and 9, which have a haptically perceivable reaction on steering system 14 and/or entire vehicle 1.
The central control unit processes signals of hazard sensor 11, and triggers various haptically perceivable warnings by activating individual brake actuators 6, 7 and optionally 8, 9 according to a predetermined pattern.
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The cyclically alternating activation of left and right brake actuators 6 and 7 on the front axle results in vibration of the steering system.
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Number | Date | Country | Kind |
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10 2008 018 474.8 | Apr 2008 | DE | national |
Filing Document | Filing Date | Country | Kind | 371c Date |
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PCT/EP2009/002589 | 4/8/2009 | WO | 00 | 11/15/2010 |