Motor vehicle with a distance-based speed control system and a lane departure warning system

Abstract

Motor vehicle (F1) - with a distance-related cruise control system (ACC), in which, in the case of following behind a vehicle in front (F2), a target distance (d_n) set by the driver to the vehicle in front (F2) is generally regulated and in which a shortened target distance (d_k) is regulated for a distance-reducing indicator effect time (t_ACC) when the indicator (BL) is activated, and - with a lane departure warning system (TLC), in which a warning, which is generally activated when there is a risk of unintentional lane departure, is suppressed for a predetermined warning-suppressing indicator activation time (t_TLC) after the indicator BL is activated, - whereby the warning-suppressing indicator effect time (t_TLC) begins at the same time as the distance-shortening indicator effect time (t_ACC) and whereby these time windows (t_ACC, t_TLC) are specified to be of equal length.

Description

[0001] The invention relates to a motor vehicle with a distance-related cruise control system and a lane departure warning system.

[0002] Such systems are well known and usually operate independently of one another in a vehicle. A lack of coordination between these systems can lead to confusing vehicle responses.

[0003] For example, DE 10 2010 041 620 A1 discloses a cruise control system for assisting the driver during overtaking maneuvers. DE 101 14 470 A1 discloses a lane keeping and speed control system, which discloses a certain dependency of the activation and deactivation logic for the speed control and lane keeping control in certain situations.

[0004] The object of the invention is to coordinate the above-mentioned vehicle systems in a motor vehicle in the sense of a predictable, uniform vehicle behavior.

[0005] This problem is solved by the features of the sole patent claim.

[0006] The motor vehicle according to the invention firstly has a distance-related cruise control system in which, when following behind a vehicle in front, a target distance to the vehicle in front set by the driver is generally regulated and in which a shortened target distance is regulated for a distance-reducing turn signal activation time when the turn signal is activated. Furthermore, the motor vehicle according to the invention has a lane departure warning system in which a warning, which is generally activated when there is a risk of unintentional lane departure, is suppressed for a predetermined warning-suppressing turn signal activation time after the turn signal is activated. According to the invention, the warning-suppressing turn signal activation time begins simultaneously with the distance-reducing turn signal activation time, with these two turn signal activation times (time windows with a predetermined duration) being predetermined to be of equal length.

[0007] The invention is based on the following considerations: Motor vehicles with the above-mentioned systems are offered, for example, by the applicant. A known distance-related cruise control system (ACC (Adaptive Cruise Control) system) regulates the speed to a predetermined target value as long as there is no vehicle ahead within a predetermined detection range in front of the vehicle. If a vehicle is ahead of the vehicle within the predetermined detection range, a target distance from the vehicle ahead is set as desired by the driver. This also provides special distance control for lane changes. During a lane change, which is detected by an activated direction indicator (turn signal), the target distance to the vehicle ahead is reduced, particularly to achieve brief acceleration, or the distance control is terminated at the time the turn signal is activated.In the first case of a reduced target distance, the vehicle accelerates to achieve the now smaller target distance. This function simulates the driving behavior of a driver without a system who begins to accelerate in their own lane before overtaking. After the indicator is switched off again, the target distance is reset to the normal value. In the second case, distance control is switched off and acceleration control is activated. In this case, the system is also given a shortened target distance as the minimum distance to the vehicle in front. When this target distance is reached, acceleration control is switched off and the system switches back to distance control.

[0008] These indicator-dependent distance control systems are sub-functions of ACC in the sense of an overtaking aid and generally specify a temporarily reduced target distance for a specific time window that is initiated by activating the indicator. This time window is referred to below as the distance-reducing indicator activation time.

[0009] Furthermore, lane departure warning systems for motor vehicles are known which have a functional module for lane keeping (lane keeping assistant) and / or a functional module for preventing a collision during a lane change (lane change assistant) in an electronic control unit (e.g. “TLC” = Time to Line Crossing or “HC” = Heading Control).

[0010] Depending on defined parameters, in particular the current distance of the vehicle from the lane markings that laterally delimit the vehicle's lane and / or the (lateral) speed at which the vehicle approaches a lane marking that laterally delimits the vehicle's lane, and possibly depending on defined situations of varying degrees of danger, a visual, acoustic, and / or haptic warning (e.g., a flashing display, a warning tone, steering wheel vibration, and / or countersteering torque) is activated. For this purpose, an electronic control unit assigned to the lane departure warning system is connected to corresponding sensors and actuators.

[0011] However, a lane departure warning system warning can be suppressed if an intended lane change is detected with at least a certain degree of probability. This is intended to reduce the driver's workload by preventing unnecessary warnings. An intended lane change is also detected, for example, when the turn signal is activated. For the technical background on this, see DE 102 05 225 A1 and DE 10 2008 051 700 A1.

[0012] Here, a time window is also started from the moment the turn signal is activated, with a predefined duration for warning suppression. This time window is referred to below as the warning suppression turn signal effect time.

[0013] According to the invention, the distance-shortening indicator action time and the warning-suppressing indicator action time are specified equally.

[0014] The invention coordinates these two time windows to achieve comprehensible reactions to the activation of the indicator.

[0015] This prevents the lane change warning system from starting to warn again even though the adaptive cruise control system is still operating at a shortened target distance for a smooth overtaking maneuver. Or, conversely, it prevents the adaptive cruise control system from returning to the normal target distance because the driver hasn't overtaken after all, but the lane change warning system still suppresses the warning when approaching too closely to the lane markings.

[0016] The drawing illustrates a preferred embodiment of the invention. It shows the motor vehicle according to the invention in an intended lane change situation.

[0017] The upper part of the drawing schematically shows a motor vehicle F1 according to the invention, which is currently traveling in a first lane S1 and will change to the adjacent lane S2 after the turn signal BL is activated. The motor vehicle F1 has a distance-related cruise control system ACC and a lane departure warning system TLC with at least one electronic control unit programmed according to the invention. Another vehicle F2 is traveling in front of this motor vehicle F1. The distance-related distance control is active. Before the turn signal BL is activated, the normal target distance d_n set by the driver is adjusted. After the turn signal BL is activated, a shortened target distance d_k is adjusted for a predetermined distance-reducing turn signal activation time t_TLC in order to prepare for an overtaking maneuver.

[0018] When the turn signal BL is activated, the suppression of the lane departure warning of the lane departure warning system TLC is simultaneously started for a predefined warning suppression turn signal activation time t_ACC: By activating the turn signal BL, the driver of the motor vehicle F1 signals an intended lane change. He begins a lane change from the first lane S1 to the adjacent lane S2 of a multi-lane road. When the motor vehicle F1 approaches the first lane marking M1, the lane departure warning system TLC of the motor vehicle F1 would issue a warning that is basically activated in the event of the risk of an unintended lane departure. However, the warning is suppressed by starting the warning suppression turn signal activation time t_ACC after the turn signal BL has been activated.

[0019] In the lower part of the drawing, the distance-reducing turn signal action time t_TLC and the warning-suppressing turn signal action time t_ACC are shown for this situation, which are started when the turn signal BL is set and which have the same duration.

Claims

[1] Motor vehicle (F1) - with a distance-related cruise control system (ACC), in which, in the case of following behind a vehicle in front (F2), a target distance (d_n) set by the driver to the vehicle in front (F2) is generally regulated and in which a shortened target distance (d_k) is regulated for a distance-reducing indicator effect time (t_ACC) when the indicator (BL) is activated, and - with a lane departure warning system (TLC), in which a warning, which is generally activated when there is a risk of unintentional lane departure, is suppressed for a predetermined warning-suppressing indicator activation time (t_TLC) after the indicator BL is activated, - whereby the warning-suppressing indicator effect time (t_TLC) begins at the same time as the distance-shortening indicator effect time (t_ACC) and whereby these time windows (t_ACC, t_TLC) are specified to be of equal length.

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