Lane departure warning system

Abstract

Lane departure warning system in which a warning (W), which is generally activated when there is a risk of unintentional lane departure, is suppressed for a predetermined time (dt) when an intended lane change is detected, wherein this warning suppression is aborted when it is detected that after the lane change there is a risk of unintentional lane departure with regard to the new lane (S2) and wherein the lateral speed (vq) at which the lane change is carried out is determined and when an intended slow lane change (LS) with a lateral speed (vq; vq1) below a predetermined threshold value (S) is detected, the warning suppression remains set for a predetermined time (dt).

Description

The invention relates to a lane departure warning system according to the preamble of claim 1.Lane departure warning systems for motor vehicles are known, which have in an electronic control unit a functional module for lane keeping (lane keeping assistant) and / or a functional module for preventing a collision during a lane change (lane changing assistant). Depending on defined parameters, in particular depending on the instantaneous distance of the own vehicle from the lane markings laterally delimiting the own lane and / or depending on the (lateral) speed at which the own vehicle approaches a lane marking laterally delimiting the own lane, and optionally depending on defined situations of different dangerousness levels, a visual, acoustic and / or haptic warning is activated (e.g. by display flash, warning tone, steering wheel vibration and / or counter steering torque). For this purpose, an electronic control unit assigned to the lane departure warning system is connected to corresponding sensors and actuators.However, a warning of the lane departure warning system can be suppressed if an intended lane change is detected at least with a certain probability. This is intended to prevent superfluous warnings to relieve the driver. An intended lane change is detected, for example, when the turn signal indicator is set.For technical background in this regard, reference is made, for example, to DE 10 2004 048 009 A1, EP 1 867 542 B1, DE 102 05 225 A1 and DE 10 2008 051 700 A1.It is an object of the invention to further improve a lane departure warning system with temporary warning suppression with regard to its reliability.This object is achieved by the features of claim 1. The dependent patent claims are advantageous further developments of the invention.The invention is based on the following considerations:The starting point is a known lane departure warning system (e.g. "TLC"=time to line crossing or "HC"=heading control) with visual, acoustic and / or haptic warning including or without active counter steering torque assistance. Such a system is intended to output a warning to the driver, in particular when there is an unintentional approach to a lane marking. The lane marking can be detected, for example, by means of cameras.In a development of such a system, the warning is suppressed if it is assumed that the driver signals an intended lane change, for example by setting a flashing signal. In order to also enable a relatively slow intended lane change without an unnecessary warning, a time window ("timer") is preferably started from the time of the flasher removal with a predefined time duration for the purpose of suppressing the warning.However, if the lane change is carried out very quickly, so that the aforementioned timer for suppressing the warning still runs even if the next lane marking of the new (adjacent) lane could already be traveled over (unintentionally) in multi-lane roads, the timer is stopped according to the invention; i.e. the suppression of the warning is canceled again.The warning on the new lane should therefore be active again after a warning suppression in the case of a fast lane change, i.e. if the lane change is faster than the timer. To determine a fast lane change, according to the invention, the lateral speed of the vehicle is determined directly or indirectly and compared with a defined threshold value. The lateral speed is the speed at which the lane marking is traveled over or at which the vehicle moves away from the lane marking or towards the new lane marking after the lane marking has been traveled over.The time duration of the timer and the threshold value for the lateral speed are determined empirically, for example, by driving tests.The invention is intended to warn the driver, on the one hand, in the situations where he is also expecting it, and, on the other hand, to relieve possibly unnecessary warnings.The drawing shows a preferred embodiment of the invention. It shows the lane departure warning system according to the invention on the basis of a lane departure situation represented over time.In the upper part of the drawing, a motor vehicle F is schematically shown, which is currently travelling on a first lane S 1 and, after setting the turn signaler, will change to the adjacent lane S 2 at two different lateral speeds vq (vq 1, vq 2). In the lower part of the drawing, firstly the basic activation signal of the warning W, the setting signal of the flasher BL, the timer for warning suppression and the lateral speed vq (in particular vq 2) are shown over time t in these situations.For the warning W, a parameter to be taken into account is in particular the distance of the own motor vehicle F from a roadway marking delimiting the own lane, in this case M 1 or M 2. For the termination of the suppression of the warning (timer, dt), a further parameter to be taken into account is, according to the invention, also the lateral speed vq at which the host motor vehicle moves away from the center of the host lane, here S 1 or S 2, toward a roadway marking delimiting the lane, here M 1 or M 2.By setting the flashing signal BL, the driver of the motor vehicle F signals an intended lane change. It starts a lane change from the first lane S 1 to the adjacent lane S 2 of a multi-lane road. When the motor vehicle F approaches the first roadway marking M 1, the lane departure warning system of the motor vehicle F would issue a first warning W, which is basically activated in the risk of unintentional lane departure (dash-dot warning W in the lower part of the drawing). However, the warning W is suppressed by starting a timer after the flasher BL is reset.When an intended slow lane change LS is detected with a lateral speed vq below a predefined threshold value S, the timer remains set for a predefined time dt for the purpose of suppressing warnings. It is assumed here that the timer takes longer than the time until an unintentional lane departure, if necessary, with respect to the new lane S 2, which would lead to the warning W (LS). In the upper part of the drawing, a first slow lane change LS with a lateral speed vq1<S is shown for this purpose. For this situation, the dot-dash line of the timer in the lower part of the drawing would continue to apply.Furthermore, a second relatively fast lane change SS with a lateral speed vq2>S is shown. For this situation, the solid line of the timer would apply in the lower part of the drawing. In the event of unintentional driving over the second roadway marking M 2, therefore, according to the invention a next warning W (SS) is already output before the timer dt expires. This is because, after the rapid lane change SS, the risk of unintentional lane departure with respect to the new lane S 2 is recognized.

Claims

Lane departure warning system, in which a warning (W), which is basically activated in the event of the risk of unintentional lane departure, is suppressed when an intended lane change is detected for a predefined time (dt), wherein this warning suppression is canceled if it is detected that the risk of unintentional lane departure with respect to the new lane (S2) exists after the lane change, and wherein the lateral speed (vq) at which the lane change is carried out is determined, and if an intended slow lane change (LS) is detected with a lateral speed (vq; vq1) below a predefined threshold value (S), the warning suppression remains set for a predefined time (dt).Lane departure warning system, in which a warning (W), which is basically activated in the event of the risk of unintentional lane departure, is suppressed when an intended lane change is detected for a predefined time (dt), wherein this warning suppression is broken off if it is detected that the risk of unintentional lane departure with respect to the new lane (S2) exists after the lane change, and wherein the lateral speed (vq) at which the lane change is carried out is determined, and if an intended rapid lane change (LS) is detected at a lateral speed (vq; vq1) above a predefined threshold value (S), the warning suppression is interrupted before the expiry of the time (dt) which is predefined.

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